copycat gettingstarted

7/28/2019 Copycat Gettingstarted

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CopyCAD

Getting Started

By Delcam plc

Issue 5.0 20/02/03 09:08


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Information contained in this guide is subject to changewithout notice and does not represent a commitment by

Delcam plc. The software described in this guide is

furnished under licence agreement and may be used orcopied only in accordance with the terms of such licence.

No part of this guide may be reproduced or transmitted inany form or by any means, electronic or mechanical,

including photocopying and recording, for any purposewithout the express permission of Delcam plc.

Program 1996 2003 Delcam plc

Important NoticeDelcam plc has no control over the use made of thesoftware described in this guide and cannot accept

responsibility for any loss or damage howsoever caused

as a result of using the software. Users are advised that all

the results from the software should be checked by a

competent person, in accordance with good qualitycontrol procedures.


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CopyCAD Getting Started Contents i

ContentsIntroduction 1

Overview.......................................................................................1Printing the Getting Started Tutorials .................................. 1

Alloy Wheel Tutorial 3Alloy Wheel Tutorial - Overview..................................................3

What Does This Tutorial Show?....................................................3Importing the Digitised Point Data ................................................ 5

Before you begin ................................................................. 6

Manipulating the View ........................................................8

Tidying up the Scan Data .............................................................. 8

Using the Triangulation wizard ...................................................10

Opening the Triangulation wizard ..................................... 10

Limiting the Triangulated Model.......................................15Deleting the Vertical Edge.................................................18

Deleting models...........................................................................19Processing the Points Manually...................................................20

Generating Scanlines......................................................... 20

Offsetting the Model..........................................................21

Limiting the Model............................................................23

Deleting the Vertical Edge.................................................28Tolerancing the Model.......................................................29

Stripping the Scanlines ...................................................... 31Generating a Triangle Model.............................................32

Deleting the Triangles on the Base .................................... 33

The Surfacing Process ................................................................. 35

Generating Curves from Boundaries..................................35

Creating Cross Section Curves .......................................... 37Creating a Curve Network................................................. 38

Generating a Surface using Curves .................................... 40Creating a Surface using Guidepoints................................42

Shading the Surfaces .........................................................44

Reversing a Surface...........................................................44


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ii Contents CopyCAD Getting Started

Creating more Surfaces .....................................................45

Completing the Model.................................................................48Saving the Surfaces ..................................................................... 49

Saving the Session.......................................................................50

Summary .....................................................................................51

Surfacing Tutorial 53Surfacing Tutorial - Overview..................................................... 53

What Does This Tutorial Show?..................................................54Importing the Triangle Data ........................................................ 55

Manipulating the View ...................................................... 56Deciding the Surfacing Strategy ..................................................56

How do I Surface the Buggy?............................................ 56

Creating the Four-Sided Surfaces ................................................57How Can I Create Surface Boundaries?.............................58

Tips for Sketching Surfaces...............................................58Sketching the Four-Sided Surfaces .................................... 59

Basic Principles of Surfacing.............................................66Creating Curves...........................................................................67

Importing Curves...............................................................67

Sketching the Bonnet Boundaries ...................................... 68

Generating the Inlet Wall Curves.......................................70

Creating the Bonnet Trimmed Surface.........................................74Creating the Air Inlet Surfaces ....................................................76

Measuring the Air Inlets .................................................... 76Opening PS-Surfacer ......................................................... 78

Creating an Extruded Surface ............................................ 79

Delete the Wireframe Curves.............................................82

Extend the Base Surface .................................................... 82

Create the Fillet Surfaces...................................................84Checking the Model ..........................................................88

Returning to CopyCAD ..................................................... 88Saving the Surfaced Buggy Model .............................................. 89

Saving the CopyCAD Session ..................................................... 89

Summary of Tutorial ................................................................... 90


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CopyCAD Getting Started Introduction1

Introduction

OverviewThis "Getting Started" is intended as a guide to new users of CopyCAD.It contains two tutorials, which show you step-by-step how to producecomplex CAD surfaces from digitised point data.

In the first "Alloy Wheel Tutorial" you are shown how to prepare point

data for an alloy wheel, triangulate it and create a few basic surfaces.

In the second "Surfacing Tutorial", you build up your understanding of

CopyCADs surfacing techniques to create a CAD model of a car bonnet.

You are also recommended to make full use of the CopyCAD ReferenceOn-line Help: this guide is designed as a supplement to help you in

"getting started".


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CopyCAD Getting Started Alloy Wheel Tutorial 3

Alloy Wheel Tutorial

Alloy Wheel Tutorial - OverviewThis "Getting Started: Alloy Wheel" tutorial is intended as a starting pointfor new users of CopyCAD. It shows the two main stages in creating asurfaced model from point data:

Creating a triangulated model from a points file Surfacing the triangulated model

The digitised data can come from conventional co-ordinate measuring

machines, tracing machines or laser scanners, and it is assumed that you

already know how to acquire the original point data.

This tutorial describes two ways to carry out the first stage. Firstly, you

are taken through the process using the Triangulation wizard. This asksyou questions about the points file and then triangulates the model based

on your answers.

Secondly, the tutorial describes the stages needed to process the file

manually. This will help you understand CopyCADs processes,including scanline generation, tolerancing, filtering, offsetting and

triangulation.When you have created your triangulated model, you can start surfacing

the model. Surfacing is covered in more detail in the second tutorial in

this guide, "Getting Started: Surfacing".

What Does This Tutorial Show?Here is the original point data that you will start with. It is one spoke in

an Alloy Wheel:


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4 Alloy Wheel Tutorial CopyCAD Getting Started

There are four main stages in generating surfaces from point data:

1. Importing the digitised data.2. Processing the data, including generating a Scanline Structure,

offsetting the Scanlines to account for the probe radius andreducing the number of points.

3. Generating a triangle model.4. Generating the surfaces.

The tutorial will go through each of these stages, to guide you through the

process of surfacing the alloy wheel model. At the end of this tutorial,

you will have produced the following surfaces:


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Importing the Digitised Point DataAfter starting CopyCAD, load in the digitised data file.

1. Select the File - Examples menu option.

The following dialog box appears:

2. Choose the file alloy.asc from the dialog box, and click onOpen.

This file contains the point data and the model appears in the

Graphics window. The view shown is from the Z direction, and thisneeds to be changed to see the model more clearly.

3. Select the View - ISO - ISO 1 menu option to get the view shownin the diagram below.


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Before you begin

It is good practice to make sure that the View toolbar and Draw toolbarare displayed. The tools available on these toolbars make it easier to

control the view, and the entities that are drawn on screen later on in theprocess.

1. Select View Toolbars from the menu bar.2. Make sure that there is a tick next to the Main, View and Draw

options, so that CopyCAD will these toolbars at the edges of the

Graphics window.

The toolbar is displayed at the right hand side of the Graphics

window as follows:


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The buttons on this toolbar are described further in the CopyCAD

on-line help. Tooltips also describe the function of each button.The Draw toolbar is displayed at the bottom of the Graphics window as

follows:

You use the Draw toolbar buttons to control the CopyCAD components

displayed. The buttons are toggles, so selecting a button once will drawan entity, pressing the button again will undraw the entity.

The buttons on this toolbar are described further in the CopyCAD on-linehelp.


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Manipulating the ViewBefore continuing the tutorial, it is a good idea to familiarise yourself

with manipulating the view. This can be done using the commands on the

toolbar.You can also change the viewpoint using the mouse as follows:

Middle mouse button click and drag on the model to rotate theview

Middle mouse button + Shift Pans the model (moves at the samesize to a different position in the Graphics window)

Middle mouse button + Shift + Ctrl Zooms to box Middle mouse button + Ctrl - Zooms in and out.

Most of the diagrams in this guide are shown using the View ISO 1

button on the toolbar.

Tidying up the Scan DataThe model shown is the original scan data, and therefore has lead-ins,which must be removed.

1. Click on the Point Editing button on the Main toolbar. ThePoint Editing side toolbar appears.In ISO 1 view you can see two of the lead in points that you need

to delete.


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2. Select the points individually by dragging a box around them usingthe Left mouse button. The selected points turn red.

3. Click on the Delete Points button from the Point Editing sidetoolbar.

4. Click on the ViewISO 3 button to display the other two leadin points that you need to delete.

5. Select them, then click on the Delete Points button.You are now ready to start getting the model ready for triangulation. Thistutorial describes two ways of carrying out this process:

Firstly, using the Triangulation wizard, which guides you throughthe process. This is described in "Using the Triangulation wizard"

on page 10.

Secondly, manually carrying out each task needed to get the modelready for triangulation. This is described in "Processing the Points

Manually" on page 20.

By repeating this main stage, you will get an understanding of the range

of CopyCADs functionality and how it can be used. The Triangulationwizard is very useful when you are starting to use CopyCAD. However,

to get the most out of this powerful reverse engineering package, you

need to have a more in-depth knowledge of how CopyCAD works.


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Using the Triangulation wizardThe Triangulation wizard helps you carry out the exact steps needed fortriangulating a points file. It also speeds up the process, reducing the

number of buttons and menu options you need to select.

Opening the Triangulation wizardIn this tutorial, you have the points model already open and displayed in

the Graphics window.

Note: If you open a points file using the Open Filebutton , theTriangulation wizard automatically opens.

1. Click on the Triangle Generation button on the Main toolbarto display a side toolbar.

2. Click on the Triangulation Wizard button . After a fewseconds, CopyCAD displays the Step 1 of the Triangulation

wizard.

Note: If you select the Non-contact option, the Wizard displays a

picture of a laser digitiser on the left

3. The Alloy.asc points file was created using a Touch probe soleave this option selected and click on Next.


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4. Type 2.0, the diameter of the probe used when creating theAlloy.asc points file, then click on Next.

Note: This Step and the next one are displayed because the

Alloy.ascwas created using a Touch probe, and needs offsetting

5. Click on Probe Centre, as this is how the probe was set up whencreating Alloy.asc, then click on the Next button.


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6. Leave the default ofSingle ordered raster scan, as this wasthe scanning method used, then click on Next.

Note: If you select one of the other options a picture of that method

is shown on the left.

7. Select Bi-directional raster scan, as this was the scanningstrategy used, then click on Next.

Note: You can tell that this was a bi-directional scan by looking at

the model it has one continuous scanline that zig zags back and

forth, so must be bi-directional.

8. Type 0.5, as this is the stepover between scanlines in theAlloy.asc, then click on Next.

Tip: Zoom in on the end of two scanlines, then select two points on

the model in neighbouring scanlines. Click on the button on the

Point Editing toolbar to display the distance in X or Y between the

two points.


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9. By default, CopyCAD makes the triangulation grid the same as themaximum stepover. Click on Next to accept this.

10.By default, CopyCAD sets triangulation tolerance to a tenth of thegrid size specified in the previous step. Click on Next to acceptthis.


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11.The final step is to remove points that you do not want to beincluded in the triangulation. As you have already carried out thisstage, click on Next.

12.Check the settings you have specified in the summary, then clickon Finish.

CopyCAD automatically processes the data based on the answers you

have given to the wizards prompts. This processing will include scanline

generation, tolerancing, offsetting and triangulation. The progress of each

of these stages will be shown in the Status bar, but further user interactionis not required in the triangulation process.

When the triangulation is complete, CopyCAD displays the followingmodel:

If you now look in the CopyCAD Explorer, you can see that a newtriangulated model has been created, tri_alloy.


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Note: Each CopyCAD process creates a new model in CopyCAD. To

see the processes carried out by the Triangulation wizard, select

Options-Input/Outputthen click on the Keep wizardintermediate modelscheck box to select it. If you then repeat the

triangulation of the Alloy.ascfile, you will see that the final modelhas been toleranced, offset and triangulated.

Limiting the Triangulated ModelBefore you can start surfacing the model that the Triangulation wizard

has produced, you must trim off the unwanted areas.

As part of the triangulation process, the model has been offset, and thishas created edges that need to be removed. You must also remove the

base plane, which represents the surface on which the alloy wheel wasplaced during scanning.

1. Click on the Model Editing button on the Main toolbar todisplay a side toolbar.

2. Click on the Limit Model button to display the followingdialog box:


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3. Make sure that the default options are as follows: Plane in theLimit To area, Other Side in the Keep area, Create for theTask option and Set for the Trim option.

4. Click on the Define LimitingPlane button to display theDefine Plane dialog box.

5. Select X Plane for the Type, and fill in 99.0 for the X value,Click on the Accept button to close the Define Plane dialog box.

A yellow representation of the limiting plane is displayed on themodel. This moves if you change the plane definition, or click on

the model to position the plane by eye.

6. Click on the View from Back (Y) button to see the area of themodel that will be removed by this limiting operation.

7. In the Limit Model dialog box, click on the Apply button.


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When the limiting is complete you can see that you have trimmed back

the triangles to the yellow line. This has limited one side.

To limit the second side, change the options as follows:

1. In the Limit Model dialog box, change the Keep option fromOther side to Normal side.

2. Click on the Define LimitingPlane button to display theDefine Plane dialog box.

3. Change the X value to -99.0. Click on the Accept button to closethe Define Plane dialog box.

The yellow representation of the plane moves to the new position

on the model.

4.

Click on Apply.To limit the third side, change the options as follows:

1. In the Define Plane dialog box, change the Type to Y Plane.The X value will become greyed out, and the Y value optionbecomes available. Enter the value 1.0 into this box, and leave theother options unchanged.

The yellow representation of the plane moves to the new position

on the model.

2. Click on View from Right (X) button , to see the area that willbe trimmed.

3. Click on Apply.The Z plane now needs to be limited to remove the base plane.

1. In the Define Plane dialog box, change the Type to Z Plane,and leave the default value of0.0 in the Z value box.

2. Click on the Accept button to close the Define Plane dialog box.The yellow representation of the plane moves to the new positionon the model:

3. Click on Apply.4. Click on Accept to close the Limit Model dialog box.5. Click on the ViewISO 1 button . The model will now look like

this:


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Deleting the Vertical EdgeThe last thing you need to do to the model produced by the Triangulationwizard, before you can surface it, is to delete the triangles that make up

the vertical edge on the outside of the spoke.

1. Click on the Triangle Editing button from the Main toolbarto display its side toolbar.

2. Click on the View From Back (Y) button , then drag the viewdown using the Middle mouse button so that the required pointsare visible.

3. Select the points by dragging a box around them using the Leftmouse button as shown below. The triangles turn red to show that

they are selected. The selection process may take a some while, as

you are selecting a fine mesh of triangles.

Note: All the triangles can be deselected using the Undobutton

or you can de-select the rogue points holding down the Ctrlkeyas you click.


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4. Click on the Delete Triangles button on the side toolbar.When you have deleted these triangles, the model is ready for surfacing.

This tutorial now describes how to get the alloy file ready for surfacing

manually.

The first step is to delete the models created by the Triangulation wizard.

You can then follow the steps that describe how to process the points file

manually.

Deleting modelsThis section describes how to delete the models created by the

triangulation process.

It is good practice to delete unwanted models, as each time a new model

is created, CopyCAD names it using the last model name and the

operation just carried out. When you have created four or five models, thenames become very long. You can rename models at any time, to make

the name shorter and more meaningful.

After carrying out the steps described in "Using the Triangulation

wizard", the CopyCAD Explorer should look like this:

To delete the models created by this process:

1. Double click on the icon to the left of the first model, alloy. Thisselects the model, turning on its light bulb. This can be fiddly ifyou are not used to it. Make sure that the lamp icon is properly lit

.

2. Select Delete All Other Models from the menu bar.3. At the Confirmation Box displayed, click on Yes to confirm that

you want to delete all models except the selected one, alloy.CopyCAD now deletes all the models you dont need any more,

leaving you with the alloy model.

The CopyCAD Explorer should now only contain one model and

look like this:

We will now look at how to process the points manually.


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Processing the Points ManuallyRather than using the Triangulation wizard, you can carry out the stepsneeded to create a triangulated model manually. This tutorial takes you

through these steps so that you know how to process files, should theTriangulation wizard be unsuitable for your points file.

The steps are as follows:

Generating Scanlines Offsetting the Model Limiting the Model Deleting the Vertical Edge Tolerancing the Model Stripping the Scanlines Generating a Triangle Model Deleting the Triangles on the Base.

Generating ScanlinesYou can now use the digitised data to generate a Scanline structure. At

the moment the model has one continuous scanline, which needs to besplit up and the links between scans need to be removed.

1. Click on the ScanlineGeneration button on the Maintoolbar. The following dialog box appears:

2. Choose the following options:


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Bi-Directional in the Scanning Strategy area Both as the Clean-up option leave the default Z Axis as the Digitising Axis leave the default Tolerance value of0.1.

3. Click on Apply. The following Scanline structure is produced.

If you click on the Zoomto box button , then draw a boxaround the ends of one side of the model, you will see that the end

links between Scanlines have been removed. This is shown below.

4. Click on Accept to close the Scanline Generation dialog box.Offsetting the ModelThe scanlines must now be offset by the Probe Radius. When a part is

scanned and a digitised model is created, the points are recorded at either

the probes tip or centre. The actual contact point with the surface is

unknown.


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When the probe is recording points where the probe contact point is the

same as the probe tip then the point taken is on the true surface. However,when the probe runs over a corner or other feature, the contact point is on

a different position on the hemisphere.

You must offset the points by the probe radius to recreate the true surfacedata.

You specify the probes diameter in the Offset Model dialog box andCopyCAD offsets the model by its radius.

1. Click on the Model Editing button on the Main toolbar todisplay a side toolbar.

2. Click on the Offset Model button on the side toolbar todisplay following dialog box.

3. Choose the Centre option for the Probe Datum, and fill in aProbe Diameter of2.0 and a Tolerance of0.1.

4. Click on Apply.You can see the progress of the offsetting on the status bar.


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5. When the offsetting process is complete, click on the View ISO 2button , and the model will look like this:

6. Click on Accept to close the dialog box.Although the model appears unchanged, if you Zoom In on the ends ofthe scanlines indicated in the figure above using the Zoom to box

button , you will see that the scanlines have all been offset and "radii"have been created at the ends of the digitised data.

As these "radii" were not part of the original data, they must be removed.This is done by limiting the model.

Limiting the Model

First, three sides of the model will be limited to remove these "radii" andthen the Z=0 plane will be limited to remove the base plane.


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1. Click on the Resize to Fit button , to view the whole of themodel again, then click on View ISO 1 button .

2. Click on the Limit Model button on the Model Editing sidetoolbar. The following dialog box appears:

3. Select Plane in the Limit To area, Other Side in the Keep area,Create for the Task option and Set for the Trim option

4. Click on the Define Limiting Plane button to display theDefine Plane dialog box.


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5. Select X Plane for the Type, and fill in 99.0 for the X value,Click on the Accept button to close the Define Plane dialog

box.A yellow representation of the limiting plane is displayed on themodel. This moves if you change the plane definition. The position

values of the limiting planes that you select depend on the size ofthe model and the probe radius, as this distance produced the

unwanted "radii" during the offsetting process.

You can see the size and the extents of the model by clicking on

the plus sign next to its icon in the CopyCAD Explorer. In thiscase, you are trimming 1mm from the Min X, Max X, and Min Y

extents and making the Min Z extent be zero.

6. In the Limit Model dialog box, click on the Apply button.This has limited one side. To limit the other sides, the options need to be

changed as follows:


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1. In the Limit Model dialog box, change the Select option fromOther side to Normal side.

2. Click on the Define Limiting Plane button again to redisplay theDefine Plane dialog box.

3. Change the X value to -99.0. Click on the Accept button to closethe Define Plane dialog box.

4. Leave the other options unchanged.The yellow representation of the plane moves to the new position

on the model:

5. In the Limit Model dialog box, click on the Apply button.6. Redisplay the Define Plane dialog box, and change the Type to

Y Plane. The X value will become greyed out, and the Y valueoption becomes available. Enter the value 1.0 into this box, andleave the other options unchanged.

7. Click on the Accept button to close the Define Plane dialog box.The yellow representation of the plane moves to the new positionon the model:


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8. In the Limit Model dialog box, click on the Apply button.The Z plane now needs to be limited to remove the base plane:

1. In the Define Plane dialog box, change the Type to Z. and type0.0 in the Z value box. Leave the rest of the options unchanged.

The yellow representation of the plane moves to the new positionon the model:

2. In the Limit Model dialog box, click on Apply. The model willlook like this:


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The base plane has not been completely removed, because the

scanlines cannot have gaps in them. If you Zoom In on the ends,you will see that the "radii" have now been removed.

3. Click on Accept to close the Limit Model dialog box.Deleting the Vertical EdgeTo tidy up the model, you now need to delete the vertical edge on the

outside of the wheel spoke. This is done easily by deleting the points on

the bottom of those scanlines.

1. Click on the Point Editing button on the Main toolbar. ThePoint Editingside toolbar appears.

2. Display the points by clicking the Draw Points button on theDraw toolbarat the bottom of the screen.

3. Rotate the view using the Middle mouse button so that therequired points are visible, then select the points by dragging a boxaround them using the Left mouse button as shown below.

Note: Points can be deselected either using the Undobutton orselecting the rogue points whilst holding down the Ctrlkey.


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4. Click on the Delete Points button on the Edit Points sidetoolbar.

The model will now look like this:

Tolerancing the ModelYou can now tolerance the model to reduce the amount of points, since

the model was scanned at a finer tolerance than is necessary for surfacing.Reducing the amount of points will speed up subsequent operations.

1. Turn the Scanlines off by clicking the Draw Scanlines buttonthen click on the View ISO 1 button . The model will look likethis:


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7. Click on Accept to close the dialog box.Stripping the ScanlinesStripping the Scanlines is another way of reducing the amount of data.

1. Redraw the Scanlines using the Draw Scanlines button onthe Draw toolbar, and undraw the points using the Draw Points

button .

2. Click on the Strip Model button on the Model Editing toolbar.The following dialog box appears:

3. Strip the Scanlines to 1 in 2, by entering the values into the StripScanlines to area, as shown above.

4. Click on Apply. The model will look like this:


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5. Click on Accept to close the dialog box.Note: When working with regular grid data as produced by laser

scanners, CopyCAD will automatically reduce the amount of data

when triangulating the model to the triangulation tolerance.

Generating a Triangle ModelTriangulation of the model is an essential step in surface creation.

1. Click on the Triangle Generation button on the Main toolbarto display a side toolbar.

2. Click on the Triangulation button on the side toolbar.3. Click on the Ordered Scans tab.

4. Make sure that None is selected as the Close Triangulationmethod, and that the other options are left unselected.


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5. Click on Apply.The model will look like this:

Note: If you cannot see the model, click on the Draw Triangles

button on the Draw toolbar at the bottom of the Graphics

window.

6. Click on Accept to close the dialog box.Deleting the Triangles on the BaseYou saw that limiting the model in the plane Z=0 did not remove the

entire base plane. Therefore, the triangles on the base must now bedeleted.

1. Click on the TriangleEditing button on the Main toolbar todisplay its side toolbar appears.

2. Click on the View From Top (Z) button on the toolbar, andZoom In on the sections shown, using the Right mouse buttonwhile holding down the Alt key.

3. Select the base triangles on one side, by using the Left mousebutton to drag a box around them as shown.


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If the whole or part of a triangle is inside the box, it will beselected. The selected triangles turn red with stars in the middle of

each triangle.

4. Select the base triangles on the other side.The model will look like this:

5. Click the Delete Triangles button on the Triangle Editingside toolbar.

The model will look like this:


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The model is now ready for surfacing.

The Surfacing Process

The triangulated model is now ready for you to start the surfacingprocess. In this tutorial we will generate curves to use when creating one

type of surface, and then create the surfaces.

When creating the surfaces, the model should be split up into "flattish"areas, vertical walls, and fillets. This creates a smoother surface set.

This section describes, step by step, how to create four surfaces on the

alloy spoke. A guide how to surface the remainder of the model is also

provided.

Generating Curves from BoundariesYou are now ready to generate curves around the edge of the triangulated

model. They will be used later to guide the direction of the surface

boundaries during surface creation.

1. Click on the Curve Generation button on the Main toolbar todisplay the following dialog box.


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2. Make sure that the Boundaries option in the Generate Fromarea is selected.

3. Leave the default values unchanged.4. Click on Apply to create curves around the boundary of the

triangle model.

In the CopyCAD Explorer, double-click on the icon to the left

of the Curves model to select it. This model contains all the Curves

created in this CopyCAD session. As you create new curves, these

are added to the model. Curves are available in all models in theCopyCAD Explorer.

As the Draw Curves button is turned on, you can see thecurve model in the Graphics window.

5. Click on the ViewISO 1 button .The curves will look like this:


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6. Click on Accept to close the CurveGeneration dialog box.Creating Cross Section CurvesNext we will create two cross section curves through the part, which will

be used in the surfacing process.

Creating curves from cross sections removes the need to pick points by

eye, and ensures an accurate curve as the sections match the contours ofthe part.

This model needs to have two curves to use when surfacing the spoke,

and these will be taken through the part as shown below.

1. Click on the View from Top (Z) button , to display the modelin a plan view.


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2. Click on the Curve Generation button on the Main toolbar.3. Click on the Triangle Model Cross Section option in the

Curve Generation dialog boxs Generate From area.

4.

In the Define Plane dialog box, select Y Plane from the Typelist box, then type 130 in the Y box.

This is the position of the first cross section curve you want to

generate.

5. In the Define Plane dialog box, click on the Accept button.6. In the Curve Generation dialog box, click on Apply to create

the cross section curve.

The curves are added to the Curves model and you can now create

the second curve.7. Click on the Define Section Plane button to redisplay the

Define Plane dialog box.

8. Repeat the steps to create a cross section curve at Y=105.9. Click on the Accept button to close the Curve Generation

dialog box.

The curves in the model should now look like the example below.

You can now convert the curves on the spoke into a curve network. Thisensures that the intersecting lines have exact crossing points.

Creating a Curve NetworkTo create a curve network from the curves.


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1. Make sure that the curves are displayed and the model looks likethis example.

2. If the model looks different, click on the Draw Curves button ,and click on the View ISO 1 button .

3. Click on the Curve Editing button to display itsside toolbar.4. Select the two curves you have just created on the spoke and then

select the curves that they meet at the boundary of the model.

5. The curves turn red to show that they are selected:

6. Click on the Create Curve Network button , on the CurveEditingtoolbar to display the following dialog box:


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7. Click on the Breakpoint Insertion to Tolerance check box to selectit.

This ensures that breakpoints, which are used to create internals

during surfacing, are created along the curves. If you leave this

check box deselected, breakpoints will be created only at

intersections.8. Click on the Apply button.9. When CopyCAD has finished constructing the curve network, click

on the Accept button.

You can now use the construction curve network to create the first of the

surfaces on the Alloy wheel.

Generating a Surface using CurvesThe surfaces can now be created. Four corner points are needed to create

a surface, and CopyCAD takes the shortest route between two points. Thecurves you have just created will be used as a guide to create the first

surface.

To do this

1. Click on the Surface Generation button on the Main toolbarto display its side toolbar.

2. Click on the Create Surface button on the side toolbar. Thisputs you in Surface Creation mode and opens the Curve andSurface Fitting Options dialog box. We are going to use thedefault settings in this dialog box to create our curves.

Note: Advanced users can change the Curve and Surface Fitting

options to suit the particular needs of a model.

3. Select the four points as shown in the next diagram, by dragging abox around them individually with the Left mouse button.


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The selected points are shown as yellow squares, with purple lines

connecting them.

4. Reselect the first point.When you re-select the first point, the surface boundaries are

closed and the first surface is created. The model will look like the

one below. The surface has a surface marker on it, which you canuse to select it.

5. Redraw the triangles using the Draw Triangles button on theDraw toolbar. The model looks like this:


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Creating a Surface using GuidepointsNow you will create a surface for the flat part of the outer centre of the

wheel. This is done using Guidepoints between the four main points toguide the surface boundaries around the circular edges.

If you select the points in a clockwise direction, CopyCAD will constructthe surface facing the wrong direction, as you will see in this example.

You can easily reverse surfaces that are wrongly orientated.

1. Change the view to a View From Top (Z) .2. Click on the Point 1 as shown in the diagram above, using the

Left mouse button.

3. Hold down the Ctrl button to produce guidepoints, and click onpoints around the curve between Points 1 and 2, following the

circular outlines of the triangles. Each guidepoint you enter appearsas a red asterisk.


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Note: Use the Undobutton if you select a point you dont want.

4. Click on the Point 2 to create the first surface boundary.CopyCAD creates breakpoints (pink asterisks) on the curve you

sketched using the guidepoints.

5. As you are using the default settings in the Curve and SurfaceFitting Options dialog box, there will be three breakpointsinserted between the points. CopyCAD uses the breakpoints as the

endpoints of surface internals, which govern the fit of the surface.

6. Click on Point 3 to create a straight surface boundary.7. Select the guidepoints between Points 3 and 4.8. Click on Point 4 to create the third surface boundary.9. Reselect Point 1 to create a surface.10.When CopyCAD has finished creating the surface, click on the

Stop Creation button on the Surface Generation side toolbar.

This takes you out of Surface Creation mode and closes the Curveand Surface Fitting Options dialog box.

11.Click on the Draw Triangles button on the Draw toolbar tosee the surface more clearly

The model now looks like this:

Again, the surface you have created may look different to that shown inthe diagram.


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Shading the SurfacesYou can shade the surfaces to get a clearer idea of what the finished

surfaces will look like.

1. Click on the View ISO 1 button on the View toolbar.2. Click on the Shade Surfaces button on the Draw toolbar.3. Click on the Draw Surfaces button on the Draw toolbarto

hide the surface boundaries and internals.

The model will look like this:

As you can see the last surface you created is wrongly orientated. Thesurface is displayed in red, which means you are looking at the inside of

the surface rather than the blue of the outside. In the next section we willreverse the surface so that they are both orientated the same.

Reversing a SurfaceDepending on the order in which you select the corner points for thesurface, you may need to reverse a surfaces orientation.

Make sure that you can see the surface boundaries and internals, which

you use to select the surface.

1. Turn off the surface shading by clicking on the Shade Surfacesbutton on the Draw toolbar.

2. Turn on the surface boundaries, internals and marker by clickingon the Draw Surfaces button on the Draw toolbar.


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3. Draw a box around some of the surface internals to select thesurface. The surface boundaries and internals turn red to show theyare selected.

Note: If you cannot select the surface, you may still be in Surface

Creation Mode: click on .

4. Click on the Reverse Surfaces button on the SurfaceGeneration toolbar.

5. When the reversing process is complete, shade the model byclicking on the Shade Surfaces button . Turn off the surface

boundaries by clicking on the Draw Surfaces button

The model will now look like this:

Creating more SurfacesNow you can create the flat surface in the centre of the wheel. This is also

done using guidepoints.

1. Redraw the triangles using the Draw Triangles button on theDraw toolbar.

2. Change the view to a View From Top (Z) .3. Click on the Create Surface button on the side toolbar.4. Click on the points as shown in the next diagram using the Left

mouse button, and holding down the Ctrl button to produceguidepoints, roughly follow the circular outline of the triangles.


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5. Reselect Point 1 to create the new surface.6. Turn off the triangles to see it more clearly and change the view to

ISO 1.

Click on the Draw Triangles button on the Draw toolbar. Click on the View ISO 1 button on the View toolbar.The model should now look like this:

The surface you have created may look different to that shown in thediagram, as the surface internals created depend on the guidepoints you

picked.

Now you will surface the fillet joining these two flat, circular surfaces

together. This is done using the existing surface boundaries. Guidepoints


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are needed to guide the direction of the new surface boundaries along the

existing surface boundaries.

1. Select the first three points as shown in the next diagram, using theLeft mouse button.

As the third side of the new surface uses an existing surfaceboundary that has two corner points in it, these must be selected as

guidepoints, to guide the new surface boundary.

2. Hold down the Control button and drag boxes around the cornerpoints between points 3 and 4 using the Left mouse button. Thecorner points will automatically be selected.

3. Click on Point 4 and reselect Point 1 using the Left mousebutton to finish off the surface.


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Completing the ModelYou can now continue in the same way to complete the surfaces over the

entire model. A more complete set of surfaces for this particular model isshown below:

If you need to delete a surface, first select it and then delete it using the

Delete Surfaces button on the Surface Generationtoolbar. When

you have finished creating surfaces select the Stop Creation buttonon the Surface Generationtoolbar.

Since the wheel is symmetrical, the surfaces for this one spoke will

probably be copied and rotated. Therefore, only the necessary parts of the

spoke need to be surfaced.

A possible order of surfacing is shown below:


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When shaded, the model looks like this:

Saving the SurfacesThe surfaces can be saved separately as an IGES file, a DUCT command

file, or a CADDS4X file, for output to another application.

Here you will save them as an IGES file.

1. Select File Export Current Model Surfaces IGES from themenu bar.

2. The following dialog box will appear:


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3. Choose the folder where you want to save the file, and type a namein the File name box.

4. Click on Save.The file is now saved with a .igs suffix.

Saving the SessionThe model can now be saved as a session file. This saves all the models

created in the session as one file.

1. Select File Save Session from the menu bar.2. The following dialog box appears:

3. Choose the folder where you want to save the file, and enter aname into the File name box.

4. Click on Save.


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The file is now saved with a .ccs suffix.

SummaryIn this tutorial you have taken the alloy wheel model through the step-by-step process from scanned data to surfaced model. You will now be ableto:

Import digitised data Use the Triangulation Wizard Delete old models Generate Scanlines Offset the Model Limit the Model Reduce the amount of data in the model Triangulate the model Generate Curves Create a Curve Network Create Surfaces Shade the Surfaces Reverse Surfaces Save the Surfaces Save the Session.

This tutorial is now complete.


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CopyCAD Getting Started Surfacing Tutorial53

Surfacing Tutorial

Surfacing Tutorial - OverviewThis "Getting Started: Surfacing" tutorial is intended as a guide tosurfacing triangle models in CopyCAD. Using the example of a carbonnet and wings, it shows step-by-step how you can create CADsurfaces on a triangle model.

This tutorial shows how you should use the different methods of creatingsurfaces in CopyCAD. It explains first how you examine the model to

decide where you will place the surface patches. You then are shown the

steps needed to create four-sided untrimmed surfaces.

It then shows you how you can create trimmed surfaces which can

include internal trim boundaries to surface awkwardly shaped areas. In

this case, we will create just one surface over an area that using four-

sided surfaces would need 21 surfaces to create a smooth finish.

Finally, the tutorial shows a few of the extensive CAD surfacing solutions

available in the PS-Surfacer editing module. With these you can easilycreate accurate surfaces over the regular features of the air inlets in themiddle of the bonnet.


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54Surfacing Tutorial CopyCAD Getting Started

What Does This Tutorial Show?Here is the original triangle data for the Delcam buggy sample model,

shown with shaded triangles.

After you have created the four-sided surfaces, the buggy will look like

the example below.

After creating the curves needed for the remaining surfaces, you fit a

trimmed surface over the bonnet area, excluding the air inlets.


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The surface model is complete when you have created air inlet surfaces

using the PS-Surfacer module. The example below, shows a complete,shaded surface model.

Importing the Triangle DataCopyCAD constructs surfaces over a triangle mesh. This can either becreated through triangulating point, scanline or grid information or by

importing a triangle model. In this tutorial, we will import a ready-

triangulated model.

To import the triangle data:

1. After starting CopyCAD, select File Examples from the mainmenu bar.

2. In the Open Example dialog box, double-click on the Surfacingfolder to open it.

3. Click on the Bonnet_Triangles.dmt file, then click on theOpen button. This file contains the triangle model for the Delcambuggy design.


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Manipulating the ViewBefore continuing the tutorial, it is a good idea to familiarise yourself

with manipulating the view. This can be done using the commands on the

View toolbar, which is displayed on the right of the CopyCAD window.You can also change the viewpoint using the mouse as follows:

Middle mouse button click and drag on the model to rotate theview

Middle mouse button + Shift Pans the model (moves at the samesize to a different position in the Graphics window)

Middle mouse button + Shift + Ctrl Zooms to box Middle mouse button + Ctrl - Zooms in and out.

Deciding the Surfacing StrategyWhen surfacing a triangle model, you must first examine it carefully and

decide where you need to position the surfaces.

You will achieve the smoothest and most accurate model by first

surfacing flattish areas, which are four-sided. You can then create the

filleted areas between the flat areas and areas with high curvature.

Creating the surfaces in this order allows you to reuse existing surface

edges and set the tangency required across the models surfaces. You canmaintain tangency to blend the model across the surfaces. Alternatively,

you can turn off tangency if you require a sharp edge.

Where the positioning of four-sided surfaces results in an three-sided or

multiple sided area, you can fit a trimmed surface.

If you require surfaces with a fixed width or radius, you can use PS-Surfacer, the surface editing module, whose tools provide the accuracy of

a CAD package.

How do I Surface the Buggy?Looking at the triangle model for the Delcam buggy, you can quickly

identify the areas that are easy to surface with four-sided patches. Theseare the wings of buggy. We can also create a rough four-sided surface on

the base of each inlet.


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For the main bonnet area, we can create a trimmed surface, excluding the

islands of the air inlets. This avoids the need to create a large number offour-sided surfaces, as shown in the examples below.

Four-sided solution Trimmed surface solution

For the air inlets, we can use PS-Surfacer to create accurate CAD

surfaces, rather than creating freehand CopyCAD surfaces. To do this, wemust first find out the draft angle on the walls, and the fillet radius at the

top and base of the inlets.

For the air inlet walls, we can create extruded surfaces from a curve. Tosurface the base of the inlets we can extend the edges of the previously

created four-sided surface. We can then create fillet surfaces around top

and bottom of the air inlet walls, linking them to the bonnet and the basesurfaces.

Creating the Four-Sided SurfacesYou can place four-sided surfaces over areas that are roughly square or

rectangular. Within these areas, you should create a new patch for eacharea of regular curvature.


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On the buggy model, we will create two surfaces over each wing. At the

base of each air inlet, we will create a rough four-sided patch, which canthen be extended in PS-Surfacer to cover the whole of the base.

Before we start, we will look at some of the ways you can create surfaces,

and some of the techniques you can use to ensure that the surfaces are ofgood quality.

How Can I Create Surface Boundaries?You can create the four boundaries for each surface as follows:

Use an existing curve.You can automatically generate curves to use from the openboundary of the model, from horizon lines, from cross sections orfrom discontinuities in the model. Alternatively, you can sketch or

import curves.

Sketch the boundary, defining the internals and tangency using theoptions on the Curve and Surface Fitting Options dialogboxs Standard tab.

By default, CopyCAD projects the curve down the current view of

the part shown in the Graphics window. If you want to guide thesurface boundary around the part, you can hold down the Ctrl

button as you click to create guidepoints.

Note: The Curve and Surface Fitting Optionsdialog boxprovides extensive options, see the on-line help for more details.

Use existing surface boundaries, already created for neighbouringsurfaces.

Tips for Sketching Surfaces Zoom in on the model as much as possible, so that you can pick

points with more accuracy.

Like This Not This

Use the view wherever you can - spin the model so that theboundary will be projected down the current view onto the model.In this way it will follow the models curvature automatically.


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Dont put boundary points or control points right on the edge of atriangle model. If you do, there is a danger that the boundary will

move off the model when you select the next point.

Use the Crosshair Cursor. This helps you to line up the cornerpoints. It also shows you the line that will be projected down thecurrent view, so you can see if the boundary will move off the edge

of a model. To turn on the Crosshair Cursor, click on the button

on the Draw toolbar at the bottom of the CopyCAD window.

Make sure that the four-sided surfaces are as near rectangular aspossible in the current view. This means that parallel internals willbe created and smoothness and accuracy will be increased.

Make sure that you pick the points in an anti-clockwise direction toensure that the surface is correctly orientated. If you pick the pointsclockwise, the surface will be reversed. Reversed surfaces are

shaded red when you click on the Shade Surfaces button onthe Draw toolbar.

Make sure that you can see the region to surface clearly, otherwiseyou might pick points on the wrong part of the model.

Sketching the Four-Sided SurfacesWe will now create two surfaces over each wing of the buggy.

Note: If you want to use an imported set of surfaces, and practice

sketching surfaces later, the four-sided surfaces are provided in the

Bonnet_4SidedSurfs.dgkfile in the Examples\Surfacingdirectory. If you import the surfaces, you must append the surface


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model to the triangle model before you continue

As you must pick the surface boundary points in an anti-clockwise

direction, make sure that you follow the steps exactly.

Sketching the First Four-Sided SurfaceTo sketch the first left hand wing surface:

1. Make sure that the model is shown in plan view by clicking on theView from Top (Z) button, .

2. Use the Zoom to Box tool , to zoom in on the top of the lefthand wing area as shown below.

3. Click on the Surface Generation button on the Main toolbarto display its side toolbar.

4. Click on the Create Surface button to go into SurfaceCreation mode.

5. Set the following values in the Curve and Surface Fittingdialog box:

Number of T breakpoints (side 1 and 3) = 12 Number of U breakpoints (side 2 and 4) = 7You can leave the other settings as we want to use the default

options. This means that surface boundaries will be projected down

the current view, tangency will be maintained with neighbouring

curves and surfaces and that breakpoints for internals will beinserted evenly.


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6. Click on the model as shown below to insert the first surface cornerpoint.

7. Zoom in on the top area and click on Point 2, as shown above.CopyCAD uses the Z view to project the first surface boundaryalong the curved wing.

8. Click on the View from Left button , then zoom in so that themodel is in the view shown below.

9. Hold down the Ctrl key and click to position guidepoints for thesecond boundary as shown above, then click on Point 3, makingsure that the point is positioned just beside the triangle model

boundary.

10.Click on the View from Top button , then zoom in again onthe top left of the wing.


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11.Click on Point 4, making sure that the point is positioned justbeside the triangle model boundary.

12.Click again on Point 1 to project the final surface boundary downthe current view and complete the surface.

13.Click on the Resize to Fit button , to see the whole of themodel as shown below.

This view shows the shaded surface. To check its accuracy, click

on the Shade Errors button, . If there are large areas of red

shading, delete the surface using the button, and try again.

Tip: You can see the problem areas by rotating the model to see if the

surface boundary has fallen off the triangle model.


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Sketching the Second Four-Sided Surface

To sketch the second left hand wing surface:

1. Zoom in on the bottom of the left hand wing area.2. If you are not already in Surface Creation mode, click on the

Create Surface button .

3. Leave the current settings in Curve and Surface Fitting dialogbox as we want to use the same number of internals, that is, 12

along the long boundary, and 7 on the short boundary to match the

internals used for the first surface.

4. Click on the first two points as shown below. This uses a cornerpoint from first surface and projects the first boundary along the

curved wheel arch.

5. Rotate the model so that the bottom curve looks like a straight line,as shown below.


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Note: If you want, you can use the Crosshair Cursor, , to lineup the points. This has the drawback however that you must

position the view so that the surface boundary is horizontal in the

view.

6. Click on Point 3, as shown above. CopyCAD uses the current viewto project the surface boundary along the curve.

7. Click on the View from Top button , then zoom in so that themodel is in the view shown below.

8. Hold down the Ctrl key and click to position guidepoints for thethird boundary as shown below, then click on Point 4, which is a

corner point from the first surface.

9. Click on Point 1 again to share the first surfaces boundary.


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10.Click on the Resize to Fit button , to see the whole of themodel as shown below.

This view shows the shaded surface. To check its accuracy, clickon the Shade Errors button, . If there are large areas of red

shading, delete the surface using the button, and try again..

Tip: You can see the problem areas by rotating the model to see if the

surface boundary has fallen off the triangle model.

You can now sketch the surfaces on the other wing. Make sure that youselect the corner points in an anti-clockwise direction so that the surface

is correctly orientated. Also, you should ensure that you pick the long

surface boundaries first and third, so that the correct number ofbreakpoints are used for each boundary.

Sketching the Inlet Base Surfaces

Finally, we will sketch a rough four-sided surface on the flat base of theeach air inlet. We will use zero breakpoints as we want to create a singlepatch surface (one with no internals). Dont try and fit the surface to

match the boundaries, as we will extend the surface to cover the whole of

the base, then trim it back using PS-Surfacer.

To create the inlet base surfaces:

1. Zoom in on the air inlets.2. If you are not already in Surface Creation mode, click on the

Create Surface button .

3. Change the settings in Curve and Surface Fitting dialog box asfollows:

Number of T breakpoints (sides 1 and 3) = 0 Number of T breakpoints (sides 1 and 3) = 0


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This will create a planar surface with no internals.

4. Click on the corner points as shown below to create a surface.

5. Click on the Shade Errors button , on the Draw toolbar. Thesurfaces should be perfectly green.

6. If there are any yellow or red areas, delete the surface and recreateit, making sure that you pick points away from the filleted corners.

7. Repeat the steps to create a surface on the base of the other inlet.Make sure that you pick the points in an anti-clockwise direction

You have now created all the four-cornered surfaces needed for the

buggy model. Next we will look at the basic principles of

surfacing.

Basic Principles of SurfacingBefore you start creating surfaces on a new model, you should consider

the following:

Do you want the neighbouring surfaces to be tangent? How many internals do you need to constrain the surface to the

underlying triangles? Is it possible to match internals in neighbouring surfaces? Can you generate curves to use from the open boundary of the

model, from horizon lines, from cross sections or fromdiscontinuities in the model?

Can you sketch curves to use as surface boundaries? Can you use the orientation of the model to determine exact

location of the surface boundaries?


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Will you need to use guide points to define the curves used assurface boundaries?

Creating CurvesWe will now create the curves needed to create the other surfaces on thebuggy.

First, we will import already sketched curves around the top of the airinlets.

Next, we will sketch curves to link the two wings at the top and bottom of

the bonnet. These will be used as boundaries for the trimmed surface overthe bonnet

Finally, we will generate cross-section curves at the base of the inlets touse when creating an extruded surface for the inlet walls.

When you have finished creating the curves, your model should look like

the example below.

Importing CurvesWe will now import a set of already sketched curves around the top of the

inlets. These will be used as internal trim boundaries for the bonnettrimmed surface.

Important: You must import curves before sketching or generating

any curves on the model. If you import curves afterwards, the newCurves model overwrites all existing curves


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To import the internal trim boundaries:

1. Select File Examples from the menu bar.2. From the Surfacing directory, select the inlet_curves.ccc file.3. Click on the Open button to import the curves into yourCopyCAD session.

Your model should now look like the example below.

Note: If you want to sketch these yourself, use the following values:

sketch the short sides first with 4 breakpoints each; then sketch the

hypotenuse with 8 breakpoints; next sketch corners to link the sides

using 4 breakpoints on each corner. You should sketch the curves in

this order so as to maintain tangency around the corners. For more

information about sketching curves, see Sketching the Bonnet

Boundaries on page 68.

Sketching the Bonnet BoundariesThe bonnet is currently bounded on its two sides by surfaces. In order to

create a trimmed surface, we need to create curves that enclose the bonneton the other two sides.

We will use a simple curve fitting option to create a smooth curve that

follows the edge of the bonnet closely.

To sketch the curves:

1. Click on the Curve Editing button on the Main toolbar.


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2. Click on the Sketch Curve button .3. In the Curve and Surface Fitting Options dialog box:

in the Standard Options tab, set the set the CurveParameterisation option to Breakpoint Insertion toTolerance.

in the Advanced Curve Fitting Options tab, set the CurveFitting option to Simple Curve Fitting (through polylinesegments).

4. Click on the View from Top button .5. Click on the corner point of the surface boundary, as shown in the

example below.

6. Ctrl-click two guide points as shown in the example.7. Click on the surface corner point on the other side to create the first

curve.

8. Hold down the Shift and Alt keys and rotate the model using theleft mouse button, so that the lower two surface corner points are inline.


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Tip: To rotate the model evenly around the X axis, use Shift-Alt-Left

Mouse button. To rotate around Y, use Shift-Alt-Middle Mouse button.

To rotate around Z, Shift-Alt-Right Mouse button.

9. Click on each corner point to create a curve between them.As CopyCAD is using the Project User Defined Path OntoModel option (set on the Curve and Surface Fitting Optionsdialog boxs Advanced Sketching Tab), the curve will followthe curvature of the bonnet. You can see this when you return tothe plan view (from the top, down the Z axis).

Generating the Inlet Wall CurvesAs the base of the inlets are on a Z plane, we can generate a line aroundthe walls using a Z plane cross section. These curves will be used to

create extruded surfaces for the walls.

To find out the Z height needed, we will first use the Measurer to find apoint at the base of the wall. The points set for the buggy is irregular, so it

is a good idea to generate a cross section through the part. This creates aline of points that we can use to find out more information about the air

inlets.

Creating a Cross Section LineWe will create a cross section through the triangle model to create a

polyline. We can then use the points on this line to find out more aboutthe air inlets. Initially, we will use the line to find the Z height of the base

of the inlet walls.

To create a cross section line:

1. Click on the Triangle Modelling button on the Main toolbar.2. Click on the Section Triangles button on the TriangleModelling side toolbar.


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3. In the Section Triangles dialog box, click on the DefineSectioning Plane button.

4. In the Define Plane dialog box, select X Plane from the Typelist box.

5. Click on the middle of one of the inlets to define the cross section,as shown in the example below.

6. In the Define Plane dialog box, click on the Accept button.7. Leave the default of1 in the Number of sections box, and click

on the Apply button to create a new model containing the crosssection line of points.

8. Click on the Accept button to close the Section Trianglesdialog box.

CopyCAD creates a new model calledsection_Bonnet_Triangles and selects it in the CopyCAD

Explorer to the left of the main Graphics window.Note: If you cannot see the cross section, click on the Draw Points

button on the Draw toolbar.

Measuring a Point

Now that we have a regular set of points through an air inlet, we can findthe Z height of the base of the wall.

To measure a point:


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1. Click on the Draw Curves button to turn the curves off, thenclick on the View ISO 1 button on the View toolbar.

This allows you to see the points clearly in the cross section.

2. Click on the Zoom to Box button , then click and drag tozoom in on the inlet wall area, as shown in the example below.

3. Click on the Measurer button on the Main toolbar.4. In the Measurer dialog box, click on the Point tab.5. Find a point at the base of the wall, just before the fillet that joins it

to the base of the inlet, and click on it.

6. Make a note of the points Z height, as displayed in the Point tabsZ box. This should be about 61.

Generating Cross Section Curves

We will now generate curves just above Z height found at the base of the

inlet walls, using a cross section. First we need to reselect the trianglemodel we are surfacing, as the cross section model,section_Bonnet_Triangles, is currently selected.

To generate the curves:

1. In the CopyCAD Explorer, double click on the icon to the left ofthe Bonnet_Triangles model name.

2. Turn off the points and turn back on the curves display, using theand the buttons on the Draw toolbar.

3. Click on the Curve Generation button on the Main toolbar.


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4. In the Curve Generation dialog boxs Generate From area,click on the Triangle Model Cross Section option.

5. In the Define Plane dialog box, select Z Plane from the Typelist box.

6. Type 62 in the Z box, as this is just above the Z height of the pointyou selected on the inlet wall.

7. In the Define Plane dialog box, click on the Accept button8. In the Curve Generation dialog box, click on the Curve Fitting

Options button.

9. In the Curve Fitting Options dialog box, enter the followingvalues:

In the Curves Parameterisation list box, select EvenBreakpoint Insertion in 3D Number of breakpoints = 24 Curve Fitting Tolerance = 0.05Leave the other default values.

10.In the Curve Generation dialog box, click on the Apply button,then the Accept button.

Finally, we need to delete the extra curve created through the

bonnet that is not part of an inlet.

11.Click on the Curve Editing button on the Main toolbar.12.Click on the extra curve, as shown in the example below.


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13.On the Curve Editing side toolbar, click on the Delete Curvesbutton .

Now you have created all the curves needed for the remaining surfaces,

you can create a trimmed surface over the main part of the bonnet.

Creating the Bonnet Trimmed SurfaceTrimmed surfaces differ from usual four-sided CopyCAD surfaces. When

you create trimmed surfaces, CopyCAD generates a larger surface

(roughly rectangular) and then uses trim boundaries to trim this surface

back to the required region. This makes this method of surface creation

very suitable for filling many sided or triangular areas.

In addition to the outer trim boundary, you can select surfaces or curvesto use as internal trim boundaries. This allows you to create cut-outs inthe surface.

In this tutorial, we will create a trimmed surface over the bonnet of thebuggy, using the curves you imported as internal trim boundaries. These

exclude the air inlets from the bonnet surface. To ensure an accuratesurface we will use 8 surface patches and a surface fit of 0.05.

The number of surface patches determines the number of internals for

surface, and the fit determines how closely the external trim boundary is

fitted to the underlying triangles.

To create the trimmed surface:

1. Click on the Surface Generation button on the Main toolbar.2. Click on the Create TrimmedSurface button on the Surface

Generation toolbar.

3. Follow the instructions in Step 1 of the Wizard to select the outertrim boundary for the surface. Make sure that you pick the four

corner points in an anti-clockwise order. Click on Next.

4. With Step 2 of the Wizard displayed, click on Next as you do notwant to use surfaces as internal trim boundaries.

5. Follow the instructions in Step 3 of the Wizard to select the curvesaround the top of the inlets as internal trim boundaries. Make sure

that you dont select the curves at the base of the inlets. Click onNext.


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6. With Step 4 of the Wizard displayed, leave 25 as the percentage ofpoint data to use for the surface fit. Click on Next.

7. With Step 5 of the Wizard displayed, move the slider bar to 8 tocreate eight surface patches. This will provide enough internals tomaintain a close fit to the underlying triangles. Click on Next.

8. With Step 6 of the Wizard displayed, leave 3 as the surface degree.This will give a smooth surface within each surface patch. Click onNext.

9. With Step 7 of the Wizard displayed, leave 0.2 for the surface fittolerance. This is the maximum acceptable deviation between thesurface and the underlying triangles. If the deviation is greater than

this tolerance, CopyCAD displays a message box informing you.

Click on Preview to see what the surface will look like.

10.If you are happy with the surface, click on Accept.The construction of the trimmed surface and associated error may

take a few minutes, depending on the processing power of yourcomputer.

If the surface fit is out of tolerance, CopyCAD displays a warning

box telling you the deviation between the surface and the

underlying triangles. Click on OK to close the box.

When construction is complete, the buggy should now look like this.


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To check its accuracy, you can click on the Shaded Errors buttonon the Draw toolbar.

Creating the Air Inlet SurfacesWe are now ready to create the surfaces for the air inlets. The first step is

to find out the draft angle of the inlet walls and the fillet radius used at thetop and bottom of the walls to join them to the other surfaces. To find out

this information, we can use the points in the cross section model that youcreated in "Creating a Cross Section Line" on page 70.

Next, we will open PS-Surfacer and create an extruded surface for thewalls. Fillet surfaces can then be created to blend the top of the walls to

the bonnet, and the bottom of the walls to the extended base surface.

Measuring the Air InletsBefore we open PS-Surfacer and create the surfaces for the air inlets, we

must first find out the inlets dimensions.

We need to know the draft angle for the inlet walls. This is the angulardifference between the wall and the Z plane normal. This can be

measured by picking two points at the top and bottom of the wall to

create a line using the CopyCAD Measurers Line tab.

Next we need to measure the radius of the fillet at the top and bottom of

the inlets. This can be measured using the Measurers Circle tab, by

picking three points on the fillet to construct a circle.


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To find out this information, we can use the points in the cross section

model that you created in "Creating a Cross Section Line" on page 70.

Finding the Draft Angle

We can find the inlet walls draft angle using the points in thesection_Bonnet_Triangles model.

To find the draft angle:

1. In the CopyCAD Explorer to the left of the Graphics window,double-click on the icon next to thesection_Bonnet_Triangles model.

2. If you cannot see the cross section, click on the Draw Pointsbutton on the Draw toolbar

3. Click on the Draw Curves button to turn the curves off, thenclick on the View ISO 1 button on the View toolbar.

This allows you to see the points clearly in the cross section.

4. Click on the Zoom to Box button , then click and drag tozoom in on the inlet wall area, as shown in the example below.

5. Click on the Measurer button on the Main toolbar.6. In the Measurer dialog box, click on the Line tab.7. Click on two points on the straight section of the wall, one at the

top and one at the bottom, keeping away from the fillets.

8.

Make a note of the angle displayed in the Line tabs Elevationbox. This should be about 75 degrees.


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As the draft angle is calculated from the Z normal rather than the Z

plane itself, this represents a draft angle of 15 degrees.

Measuring the Fillets

We can now use the same cross section to find out the fillet radii at thetop and bottom of the inlet walls.

To find the fillet radii:

1. Zoom in again on the points, drawing a box around the top fillet.2. In the Measurer dialog box, click on the Circle tab.3. Pick three points on the fillet, making sure that they are evenly

spaced over the curve.

Note: The curve of the circle should be over the points in fillet. Ifthey are not, pick another point, then click on the Refreshbutton

on the View toolbar, then pick the remaining two points.

4. Make a note of the value displayed in the Circle tabs Radiusbox. This should be about 2mm.

5. Repeat the steps to measure the bottom fillets radius. Make a noteof the radius value, which should be about 1mm.

Opening PS-SurfacerYou are now ready to create the inlet surfaces using PS-Surfacer. First wemust reopen the Bonnet_Triangles model, which contains the existingsurfaces.

Important: Once you have opened PS-Surfacer, you must not work in

the CopyCAD window. If you change the CopyCAD model or close

the CopyCAD window, PS-Surfacer will be unable to transfer the

surfaces back to CopyCAD at the end of the PS-Surfacer session

To open PS-Surfacer:


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1. In the CopyCAD Explorer to the left of the Graphics window,double-click on the icon next to the Bonnet_Triangles model.

2. Click on the Surface Editing button to transfer the curvesand surfaces to the PS-Surfacer module.

PS-Surfacer opens in a different application window.

PS-Surfacer contains a wide range of curve and surface creation options.

To see the different types of surfaces you can create:

1. Click on the Surface button on the Main toolbar.You will see that the drop-down button at the end of the toolbar

changes from a Selection tool to a Surfacing tool .

2. Click on the drop-down button to display buttons for the range ofsurfaces you can create with PS-Surfacer.

If you hover the mouse over each one, you will see a tool-tipdescribing the type of surface it creates.

Creating an Extruded SurfaceFirst, we will create the walls of the inlets using extruded surfaces.

1. Click on a curve at the bottom of an air inlet wall to select it.Note: If you cannot select a curve as the whole model is selected,click on the background to de-select the model first.


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2. Click on the drop-down button next to the Surface option listto display the available surface types.

3. Click on the Extrusion button .PS-Surfacer creates an extruded surface of a default length.

4. To view the extruded surface more clearly, click on the ISO 1button .

5. Double-click on the extruded surface to display the PrimitiveExtrusion dialog box.


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6. Change the following values for the extruded surface: Length = 15 Draft Angle = 15 Reverse check box = selected

Note: Setting a length of 15 ensures that the walls are higher than

the bonnet, ready to be filleted and trimmed back.

Note: You need to reverse the extruded surface, otherwise it will be

wrongly orientated with the reverse of the surface on the inside of

the inlet. This can be seen if you shade the model by clicking on the

Shaded Viewbutton on the View toolbar.

7. Click on the Accept button.8. Click on the Shaded View button on the View toolbar to

display the amended extruded surface as shown in the example

below.


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5. Click on the Edit Toolbar button on the Main toolbar.6. Click on the Point limit button on the Edit toolbar.7. Move the cursor over one of the surfaces boundaries until the

cursor looks like a magnet with the word, On, next to it, .

8. Click and drag the boundary until it extends past the wall surface.9. Repeat this step to extend all four of the surfaces boundaries, as

shown in the example below.

10.Now, rotate the model using the middle mouse button so that youcan see the extruded wall surface clearly.

11.Extend the walls downward using the same method so that the baseand wall surfaces intersect in all directions.

12.Shade the model and rotate it to make sure that the two surfacesintersect, as shown in the example below.


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13.Repeat the steps to extend the other inlets walls and base.Create the Fillet SurfacesWe are now ready to create the fillet surfaces for the air inlets.

Creating the Top Fillet

The top fillet will link the bonnet to the inlet walls. We know that it has aradius of 2mm, as this was measured from the original triangle model.

First, we need to create a composite curve around the internal trim curve

of the bonnet surface. We will then create the fillet surface.

To create the top fillet:

1. Click on the ISO 1 button , so that you can see the surfacesclearly.

2. Click on the Zoom to Box button , then click and drag tozoom in on one of the inlets.

3. Hold down the Alt key and click on the edge of one of the bonnetsinternal trim boundary.

A composite curve is created around the boundary, marked by a

yellow line with blue points.


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Tip: It is easier to pick the internal trim curve if just the bonnet

surface is displayed.

To blank the extruded surface, click on it and press Ctrl-J.

When you have created the composite

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