proe surfacing - module 9

Module 9: Analyzing Surface Models

Lab Exercises

If you are ready to start on the exercises for this module, please click the links below.

Exercise 1: Analyzing the Shaver Exercise 2: Creating a Mouse with Curvature Continuity (Challenge) Exercise 3: Analyzing the Air Filter Cover (Challenge)

Lecture Review

If you would like to review a text-based version of the materials presented in this lecture, please click here.

IntroductionWhen designing products using surface features, the transitions between surfaces play an important role. Continuity conditions at the edges of the surface sets or quilts determine how smooth these transitions are. The treatment of rounds at the edges does not always give desired results. In such scenarios, you can use blended surfaces with continuity conditions that are defined at the edges. To create aesthetically pleasing surface models, you need to analyze the model characteristics using different analysis tools. Surface analysis techniques enable you to analyze the quality of edges and surfaces and display the results using different methods. These can be effectively used with surface modeling techniques to improve the overall quality of surfaces in models. Creating models with high-quality surfaces requires constant use of different analysis tools for checking the curve and the surface quality.

ObjectivesAfter completing this module, you will be able to:

Define the need to evaluate the surface models. Describe the various surface analysis tools. Create and analyze curvature continuous surfaces.

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Analyzing Surface ModelsTo create high quality surfaces

With intended smoothness and continuity – You check tangent and curvature continuity using tools like Shaded Curvature (Gaussian), Dihedral Angle or Sections.

With intended curvature – You check the curvature values or dispersion to check that there are no unwanted high curvature zones, which would signify that there is a problem in the surfaces. For example, a kink in the surface would display a very sharp rise in curvature and could be easily located using the Shaded Curvature (Gaussian) or Curvature (Porcupine) tool.

Without distortions – Kinks or small patches are common problems in surface models. These may cause problems in adding thickness while creating a solid part or while creating manufacturing sequences.

To prepare surface model for part design With the possibility of adding intended thickness – To add thickness in

an open quilt, or to shell a solid created using a closed quilt, it should not have a radius smaller than the thickness. Sometimes, it is the design intent (fillets or blends with small radii) but if you have unintended smaller radii (high curvature) then the surface model will fail in protrusion or shelling (offsetting).

With adequate clearances from internal parts – While designing enclosures, you need to make sure that the thickened quilts have intended gaps from the internal parts.

To prepare surface model for manufacturing

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With appropriate surface sides – Many operations, like creating machining sequences, take the surface side into account. The quilts in your surface model should have the correct sides. You check the side using the Normal tool.

With appropriate draft angle – While creating plastic-molded, metal-forged, or cast parts, you need to consider their ejection from the mold. While creating parts using surfaces, you do not control the draft angle as you do in the modeling of solids. You need to build the required draft angle while modeling. Therefore, you need to check it after finishing the model.

To create aesthetic shapes With intended reflections – Reflections are important factors in designing

aesthetic shapes and determine the visual characteristics of a product. As a designer of visual characteristics of enclosures, you need to evaluate them when you are designing shapes. In shiny objects, particularly the ones that are used outdoors, the reflections play a major part in determining the visual characteristics of a product. Use the Reflection tool to determine the reflections.

Using Different Tools to Analyze Surface Models Pro/ENGINEER Wildfire 3.0 offers many different tools to suit different

modeling requirements. Depending on the objective, you can use specific tools to analyze surface models. Certain tools enable you to analyze the surface models for different characteristics such as continuity and distortions.

The table in the slide displays a list of various tools that are used for different analysis needs.

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Using Curve Analysis ToolsUsing Curvature tool.

You can use the Curvature tool to create the smoothness and continuity of curves that form the framework of surfaces. The figures on the top-right corner of the slide illustrate using the curvature tool to analyze curves.

Using Dihedral Angle tool. The Dihedral Angle tool measures and returns a numerical value of the

angles between the tangents of adjoining surfaces that occur along a common edge. This is useful when determining whether two surfaces are tangent (G1), or the extent to which they deviate from tangency.

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Using Surface Analysis Tools Analysis tools use fringe plots or graphical representations on the model to

display the results of analyzing the surface model. Pro/ENGINEER provides numerical values of the analysis when using both fringe plots and graphical plots.

Fringe plot Some of the analysis tools use fringe plots when analyzing surface models.

Pro/ENGINEER uses fringe plots to shade the selected surfaces in order to represent values in a color range. When looking at a fringe plot, you need to know what each of the colors represent. The hot colors of the spectrum represent large positive values, whereas the cool colors, such as blue, represent highly negative values.

Graphical Some of the analysis tools use graphical plots to display the results when

analyzing surface models. You can see the graphical plots on the model to determine the continuity or smoothness of surfaces, as shown in the examples on the slide.

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Using Surface Analysis Tools (cont.)Shaded Curvature (Gaussian)

Pro/ENGINEER determines the Gaussian curvature as the product of the smallest and largest normal curvature for every point on the surface. This can produce positive values (ridges), negative values (saddles), and zero values (example, cylinders, and planes). You can use the Gaussian curvature tool to check:

o Surface Character – Use it to display surface curvature in order to validate the design intent.

o Distortions - You can detect unwanted high curvature areas in a surface that may pose problems in manufacturing.

o Surface Continuity –You can detect discontinuities in the surface based on the discontinuities that appear in the fringe plot.

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Using Surface Analysis Tools (cont.)Sections

When you perform a section curvature analysis, Pro/ENGINEER creates the curvature fringe plot of cross-section cuts that are parallel to a reference plane. When you select a datum plane or planar surface, the system calculates the surface curvature parallel to the selected plane. Whereas Gaussian curvature analysis effectively depicts the distortion of the surface in two directions, section curvature analysis enables you to examine specific areas in one direction at a time.

Slope You use the Slope Analysis tool to visualize the way a surface slopes away

from a selected plane. The system renders the slope of a surface relative to a reference plane by calculating the sin (á), with results ranging from –1 to +1. For example, a 45-degree angle to a reference plane results in a 0.707 slope.

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Using Surface Analysis Tools (cont.)Draft

Using the Draft tool, you can check the draft angle on the surfaces of the solid model by setting up a plane to define the direction of pull for the mold. This enables you to identify areas that could become problematic when the part is pulled from a mold during manufacturing.

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Using Surface Analysis Tools (cont.)Curvature (Porcupine)

Using the Curvature tool, you can graphically display the normal curvature of a surface using isolines (equally spaced lines that display the contour of the surface in one direction) and line segments normal to the isolines. The curvature plots are also known as porcupines. The normal line segments are equally spaced along the isolines. Their length is proportional to the surface’s normal curvature in the isolines direction at that point. You can display the isolines on the surface in either of two directions or both. The porcupine is an excellent way to show discontinuities in surface curvature.

Using Surface Analysis Tools (cont.)Curvature (Normals)

Using the Curvature tool, you can display vectors normal to a selected surface.

The top figure displays the two adjacent surfaces having different sides. This would lead to manufacturing problems.

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The bottom figure displays the surface distortion being highlighted using Normals.

Using Surface Analysis Tools (cont.)Reflection

Using the Reflection option, you can simulate the reflection of light from a linear source that hits the surface from a particular direction. You can show the reflecting curves that pass through selected points, all those within a specified range of visibility, or those in the entire range of visibility from a selected viewing direction.

The figures in the slide illustrate reflection curves on the Shaver body. Breaks in the reflection curves indicate problem areas.

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Using Surface Analysis Tools (cont.)Radius

Using the Radius tool, you can determine the minimum and maximum radius of a surface. This is useful for determining the maximum tool radius that can be used in a manufacturing operation.

Offset Using the Offset tool, you can create a mesh offset from a selected surface,

which is useful for exaggerating slight changes to check the quality of the surface. Visible cusps in the offset mesh show a radius of curvature smaller than the offset distance. This tool is useful for interrogating geometry that fails when you create thin protrusions or shells.

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Using Model Analysis Tools You use the Model Analysis dialog box to analyze model properties. If the

selected objects do not interfere, the minimum clearance appears graphically as a red line. A small red circle with a cross hair appears at each end of the line to identify the location at which the clearance is being measured. The clearance value appears in the Message window. If there is interference, the system highlights the volume of interference and provides the value or highlights the curve or point of intersection, as appropriate for the selected items.

Global Clearance The Global Clearance type of analysis is available in Assembly and Drawing

modes. You use the Global Clearance type to calculate the clearance between each part and sub-assembly of a model.

Global Interference The Global Interference type of analysis is available in Assembly and Drawing

modes. You display information about interference between each part or sub-assembly in a model.

Thickness Analysis This analysis is used to check the cross-sectional thickness on a model. You

can enter maximum and minimum thickness values. The analysis tool checks the Over Max and Below Min locations on the model and displays the information graphically and in a table form. It also displays the cross-sectional area at each of the X-sections.

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Creating Curvature Continuous Surfaces As with curve geometry, designers analyze surfaces to locate imperfections

and to verify tangency and curvature with mating surfaces. To the consumer, aesthetic parts appear as one continuous freeform shape. Often however, the underlying shape is actually made up of a series of interconnected surfaces that fit smoothly across the entire shape. Surface analysis helps designers achieve the end result - a completed product.

You will learn about the following in the next few slides: o Curvature of a surface. o Continuity conditions. o Creating curvature continuity. o Analyzing curvature continuity.

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Curvature of Surface Curvature is defined as a portion of a surface that is proportional to 1/r at any

given point on a curve. Therefore, the smaller the radius value, the greater the curvature will be. This is illustrated in the figure at the top of the slide.

To detect changes in curvature, you can use a combination of surface analysis tools available with Pro/ENGINEER. The figure at the bottom of the slide shows a cross-section curvature plot, which graphically displays the range of curvature as a comb along the curve.

When designing surfaces with curvature, keep in mind the following: o A straight line has a zero curvature since 1/r (where r is infinite) =

zero. o A true arc has constant curvature at all points along the curve, based

on its radius. o Splines, in general, have constantly changing curvature.

Geometry can contain inflection points, where the curvature switches from one side of the surface to the other.

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Continuity Conditions When geometry is joined at a common boundary, the surfaces can meet at

three different levels of continuity: o G0 continuity. o G1 continuity. o G2 continuity.

As we can see, the three figures in the slide display various continuity conditions. Note the following:

o The straight-line curvature plot of the surface in the G0 condition in the first figure.

o The continuous slope in the G1 condition in the second figure. o The continuous curvature plot denoting the G2 condition in the last

figure. To attain a higher order of smoothness between the surface patches, we

need to define the continuity as curvature continuous or G2. We may need to create G2 surfaces for aesthetic or engineering reasons such as:

o Exterior panels of automobiles that have a shiny and glossy surface finish, and have painted, chrome-plated, and glass surfaces. These are called Class A surfaces.

o Products, like valves and flow meters, where smooth surfaces are needed to improve fluid-dynamic (or aerodynamic) properties.

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Creating Curvature Continuity The creation of curvature continuous surfaces in a given model depends on

the existing features that are referenced to create the surfaces. To create the curvature continuous surfaces, references like curves or edges

should have curvature continuity. When creating a surface from boundaries, the new surface can only be

curvature continuous in one direction. (Style surface features can have curvature continuity on all four boundary edges.)

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Analyzing Curvature Continuity It is a good practice to analyze the results when you create curvature

continuous surfaces. Use Shaded Curvature (Gaussian), Sections (sectional curvature plot) or Curvature (Porcupine) tools to analyze the curvature continuity. These plots graphically display the conditions in different manners.

o Shaded Curvature (Gaussian) – The product of the smallest and largest normal curvatures for every point on a surface. This produces fringe color plots showing positive, negative, and zero values for surfaces and planes. A sudden change in the color pattern denotes a change in curvature.

o Sections – Displays the surface curvature in a comb. The plot is valid only for that cross section.

o Curvature (Porcupine) – Displays isolines and line segments normal to the isolines on a part.

In surfaces that curve together tightly in both directions, the magnitude of the curvature is relatively high, whereas in areas which resemble the plane, the curvature is low.

Exercise 1: Analyzing the ShaverObjectivesAfter successfully completing this exercise, you will know how to:

Evaluate the quality of the surfaces. Modify surfaces to enhance quality.

ScenarioYou continue to develop the Shaver model. In order to create a smooth and high quality surface model, you are evaluating the model quality using various analysis tools.

Task 1. Inspect the quality of surfaces visually.

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1. In the Folder Browser , browse to the module_09 folder. o Right-click the module_09 folder and select Set Working Directory. o Open the BODY_MASTER_ANALYZE.PRT.

2. If necessary, click Datum Planes , Datum Axes , Datum Points ,

and Datum Coordinate Systems from the main toolbar to disable their display.

3. Examine the surface model. o Notice that the surfaces appear smooth without any apparent

distortion.

BODY_MASTER_ANALYZE.PRT

Task 2. Start analyzing the upper surface, using the Porcupine tool to check the surface quality.

Many of the following tasks utilize small pop-up windows that can get lost behind the main

Pro/ENGINEER window. To ensure ease of use, create a small gap between the Pro/ENGINEER

window and the right edge of your screen, and place any dialog boxes in the gap for easy

access.

1. Click Analysis > Geometry > Curvature.o Right-click to query and then select the entire upper quilt, as shown in

the following figure.

Selecting the Upper Body Quilt

2. Notice that the minimum and maximum curvature values are displayed in the

Analysis tab of the Curvature dialog box.o Notice that the initial porcupine display is cluttered.

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Porcupine Display

3. Select the Definition tab in the Curvature dialog box.

o In the Plot Second Direction area, type 0 for the Quality and Scale, pressing ENTER for each.

o Notice the second direction curves are not displayed, uncluttering the display.

o Notice the sharp change in curvature in the indicated area.

Porcupine Plot- First Direction

4. Select the Analysis tab and click Saved.

o Click Complete Analysis to save ANALYSIS_CURVATURE_1.

5. Click Analysis > Saved Analysis from the main menu. o Click Hide Analysis to toggle off ANALYSIS_CURVATURE_1. o Leave the Saved Analysis dialog box open for now.

6. Click Analysis > Geometry > Curvature.o Right-click to query and select the previous quilt again. Notice that the

initial porcupine display retains the previous settings. o Select the Definition tab. o In the Plot Second Direction area, type 20 for the Quality and 0.8 for

the Scale, pressing ENTER for each. o In the Plot area, type 0 for the Quality and Scale, pressing ENTER after

each. o Notice the sharp change in curvature in the indicated area.

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Porcupine Plot- Second Direction

7. Select the Analysis tab and click Saved if necessary.

o Click Complete Analysis to save ANALYSIS_CURVATURE_2.

9. Locate the Saved Analysis dialog box (which should be still open). o Click Hide Analysis for ANALYSIS_CURVATURE_2 to toggle its

display off.

o Close the dialog box when finished.

Task 3. Use a shaded curvature display to gain more insight into the surface quality.

1. Click Analysis > Geometry > Shaded Curvature.o Right-click to query and select the previous upper quilt. o Drag the Color Scale dialog box to the right of the Pro/ENGINEER

window. o Click Saved from the Analysis tab to set the saved name to

ANALYSIS_SHADED_1.

Shaded Curvature

2. Select the Definition tab and change the plot type from Gaussian to Mean.

o Notice the color gradient changes according to the color scale, depending on the amount of curvature present.

o Smooth transitions of color throughout the spectrum are normal. The yellow and red area is not necessarily a problem. This area simply has greater curvature.

o Notice the thin strip of dark blue shading on the left side of the model. This area is not currently blending smoothly.

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Shaded Mean Curvature

3. Select Gaussian as the Plot Type.

o Click Logarithmic Scale from the Color Scale dialog box. o Notice that the blue stripe invades the red region and the red stripe

invades the blue region. o The curvature in this stripe is not smooth.

Gaussian Curvature with Logarithmic

Display

There are many ways to analyze a surface. Curvature (Porcupine) plots and various shaded

displays often reveal similar findings.

4. Click Two Color from the Color Scale dialog box. o Notice the stripe effect again. The two-color plot is useful since the two

colors indicate positive and negative curvature respectively. o The stripes are caused by a thin surface curving the opposite way from

the neighboring surface.

Gaussian Curvature with Logarithmic Display

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5. Click Complete Analysis to save ANALYSIS_SHADED_1. 6. Click Analysis > Saved Analysis from the main menu.

o Click Hide Analysis for ANALYSIS_SHADED_1 to toggle its display off.

o Close the dialog box.

Task 4. Examine the reflection curves in the model.

1. Click Analysis > Geometry > Reflection. o Right-click to query and select the upper quilt again. o Press CTRL, then right-click to query and select the lower quilt. o Slowly rotate the model to view the changing reflection. o Notice that there are breaks in the reflection around the previously

identified stripe.

Reflection Curves

2. Click Saved from the Analysis tab to set the saved name to

ANALYSIS_REFLECTION_1.o Click Complete Analysis to save ANALYSIS_REFLECTION_1.

3. Click Analysis > Saved Analysis from the main menu. o Click Hide Analysis for ANALYSIS_ REFLECTION _1 to toggle its

display off. o Close the dialog box.

Task 5. Since curves are primarily responsible for the surface quality, analyze the

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curves to figure out why the surface quality is not smooth.

1. Click Analysis > Geometry > Curvature from the main menu.o Select the edge shown in the following figure. o Drag the scale handle to approximately 10. o Notice the curvature has a dip in the curvature plot, similar to the first

direction curvature plot analyzed earlier.

Curvature of Selected Edge

2. Click Quick from the Analysis tab.

o Click Complete Analysis .

3. Select the OFFSET_CURVE group from the model tree. o Right-click and select Unhide.

4. Click Analysis > Geometry > Curvature from the main menu.o Select the curve shown in the following figure. o Drag the scale handle to approximately 25. o Notice this curve also has a dip in the curvature plot.

Curvature of Selected Edge

5. Click Quick from the Analysis tab if necessary.

o Clico k Complete Analysis .

Task 6. Clean up the curvature problems on the first of two curves.

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1. Select the TOP_PROFILE sketch from the model tree. o Right-click and select Unhide.

2. With the sketch still selected, right-click and select Edit Definition.

o Click Modify Values , and select the spline.

o Click Curvature Analysis from the dashboard. o Edit the Scale to 5. Notice the dip in the plot.

Spline Curvature

3. Place the cursor over the highlighted point in the following figure.

o Right-click and select Delete Point. o Notice the curvature now ramps up quickly, but no longer has the dip

where curvature decreased slightly.

Deleting Spline Point

4. Click Complete Feature from the dashboard.

o Click Complete Sketch . o With the TOP_PROFILE sketch still selected, right-click and select Hide.

Task 7. Clean up the curvature problems on the second of two curves.

1. Expand the OFFSET_CURVE group in the model tree and select Sketch 1.o Right-click and select Edit Definition.

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o Click Curvature Analysis from the dashboard. o Edit the Scale to 10. o Notice the waviness in the plot, as shown in the following figure.

Curvature Plot


o Modify the upper endpoint curvature value from 40 to 60. o Modify the lower endpoint curvature value from 30 to 80.

3. Select the background to de-select all items.


o Click Curvature Analysis from the dashboard. o Notice the waviness in the plot has been greatly reduced.

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Improved Curvature


o Click Complete Sketch .

Task 8. To correct the curvature irregularity that we previously noticed in the stripe, create datum points that will be used as control points in the boundary blends.

1. Click Datum Planes from the main toolbar to enable their display. 2. Drag the Insert Indicator just above Boundary Blend 1 in the model tree.

3. Start the Datum Point Tool from the feature toolbar.o Select a location on the sketch, as shown in the following figure. o Edit the name of the Point to CTRL1. o Edit the offset ratio to 0.075. (Do not click OK yet).

Point CTRL1 Created

4. Right-click and select New Point.

o Select a location on the sketch, as shown in the following figure.o Edit the name of the Point to CTRL2. o Edit the offset ratio to 0.80. o Click OK to complete the datum point.

Point CTRL2 Created

5. Click Datum Points from the main toolbar to enable their display.

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6. Press CTRL and select DTM2 and Datum Point 485 (within the OFFSET_CURVE group) from the model tree.

o Right-click and select Hide.

7. Click Datum Planes from the main toolbar to disable their display. 8. Select the Insert Indicator , right-click and select Cancel.

o Click YES in the message window.

Datum Points Created

Task 9. Redefine Boundary Blend 1 to use CTRL1 as a control point.

1. Press CTRL and select the two copy geometry features in the top of the model tree.

o Right-click and select Unhide.

2. Select Boundary Blend 1 from the model tree.o Notice the stripe is caused by the double lines on the surface.

Surface with Stripe

3. With Boundary Blend 1 still selected, right-click and select Edit Definition.

o Select the Control Points tab and select Second. o Select the first undefined chain. o Select the center X on the right, then CTRL1, and then the center X on

the left. o Notice that the center stripe has been removed, and is now a single

line, as shown in the following figure.

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Control Points Added


o Boundary Blend 2 fails due to the changed control points in Boundary Blend 1.

o Continue to the next step to resolve the failure.

Task 10. Resolve the failure on Boundary Blend 2.

1. Click Quick Fix > Suppress > Confirm > Yes from the menu manager. o Notice that the failing Boundary Blend 2 feature is suppressed.

2. Select the BOTTOM_PROFILE curve from the model tree.o Right-click and select Unhide. This enables us to select this boundary

while in resolve mode.3. Select Boundary Blend 2 from the model tree, right-click and selected

Resume.o Click Quick Fix > Redefine > Confirm from the menu manager.

4. Select the Curves tab in the dashboard.o Notice that Chain 1 under the First Direction has a red dot, indicating a

missing reference. We redefine all curves for completeness. o Right-click over the model. Notice that First Direction Curves is

active. o Right-click again and select Clear. o Press CTRL and select the two curves (top then bottom) as shown.

Selecting an Edge

5. Right-click and select Second Direction Curves.

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o Right-click and select Clear. o Configure the first boundary, as shown in the following figure.

To configure this boundary, select an edge, press SHIFT, query and select the tangent chain,

and then press SHIFT and drag the endpoint handle to snap it.

First Boundary Configured

6. Press CTRL and configure the second boundary, as shown in the following

figure.

Second Boundary Configured

7. Press CTRL and configure the third boundary, as shown in the following

figure.

Boundary 3 Configured

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8. Notice a stripe is also forming on this boundary blend.

o Click Complete Feature from the dashboard to ensure the feature is correct thus far.

9. With the feature still selected, right-click and select Edit Definition.o Select the Constraints tab. Configure, as shown in the following

figure.

Boundary Conditions Defined

10. Select the Control Points tab and select the Second direction.

o Select the first undefined chain. o Select the center X on the right, then CTRL2, and then the X, second

from the bottom on the left. o Click Complete Feature from the dashboard. o Click Yes from the Menu Manager to exit resolve mode. o Notice that the stripe has been removed.

Boundary Blend 2 Redefined

Task 11. Hide all construction geometry.

1. Select anywhere on the background to de-select all items. 2. Press CTRL and select the two copy geometry features in the top of the

model tree.o Right-click and select Hide.

3. Press CTRL and select the BOTTOM_PROFILE, OFFSET_CURVE group and the Datum Point feature used for the control points.

o Right-click and select Hide.

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Task 12.

Re-analyze the surface quilts.

1. Click Analysis > Saved Analysis. o Expand the dialog box. There should be four saved analyses.

Saved Analyses

2. Select Display Analysis for ANALYSIS_CURVATURE_1 to display it.

o Click Edit Analysis and select the Definition tab. o Type 20 and 0.8 for the Quality and Scale in the Plot area. o Type 0 for Quality and Scale in the Plot Second Direction area. o Notice the improved curvature plot compared to before the

modifications.

ANALYSIS_CURVATURE_1

3. Select Hide Analysis for ANALYSIS_CURVATURE_1 to disable its display.

o Select Display Analysis for ANALYSIS_CURVATURE_2 to display it.

o Click Edit Analysis and select the definition tab. o Type 0 for the Quality and Scale in the Plot area. o Type 20 and 0.8 for Quality and Scale in the Plot Second Direction

area. o Notice the improved curvature plot compared to before the

modifications.

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ANALYSIS_CURVATURE_2

4. Click Complete Feature from the Curvature Dialog box. 5. From the Saved Analysis dialog box, click All > Hide All.

o Close the Saved Analysis dialog box

6. Press CTRL and select the upper quilt and then the lower quilt (the two boundary blend features).

o Start the Merge Tool from the feature toolbar. o Click Complete Feature from the dashboard.

Merging Quilts

Now that the surfaces are merged, the saved analyses will appear for both quilts.

7. Click Analysis > Saved Analysis.o Select Display Analysis for ANALYSIS_SHADED_1 to enable its

display.

o Click Edit Analysis and select the definition tab.

o Click Rainbow Plot and select Logarithmic Scale . o Change the fringe plot scale if necessary and notice the improved

shaded curvature plot. The stripe has been eliminated.

Notice that with this type of plot, the warm colors indicate positive curvature and the cool

colors indicate negative curvature.

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ANALYSIS_SHADED_1

8. Click Complete Feature from the Curvature Dialog box. 9. Select Hide Analysis for ANALYSIS_SHADED_1 to disable its display.

o Select Display Analysis for ANALYSIS_REFLECTION_1 to display it. o Notice the improved reflection lines.

ANALYSIS_REFLECTION_1

10. From the Saved Analysis dialog box, click All > Hide All.

o Close the Saved Analysis dialog box.

You can also click Analysis > Hide All from the main menu.

Task 13. Check areas of concern for information.

1. Click Analysis > Geometry > Point.o Select a location as shown. o Investigate the provided information in the dialog box. o Click Complete Analysis .

Point Analysis

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2. Click Analysis > Geometry > Radius.

o Select a similar location as selected previously. o Investigate the provided information on-screen and in the dialog box. o Click Complete Analysis .

Radius Analysis

Task 14. Analyze the quilt to see if it will thicken properly using the Offset tool.

1. Click Analysis > Geometry > Offset.o Query and select the entire quilt. o Drag the offset handle toward the inside of the quilt to a value of 2. o Notice that there are no intersecting mesh lines. A material thickness

of 2 will work.

Offset Mesh of 2

2. Drag the offset handle toward the inside of the quilt to a value of 5.

o Zoom in and notice that there are some intersecting mesh lines. A material thickness of 5 will not work.


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Offset Mesh of 5

3. Click Save from the main toolbar and click OK. 4. Click File > Erase > Current > Yes.

This completes the exercise.

Exercise 2: Creating a Mouse with Curvature Continuity (Challenge)ObjectivesAfter successfully completing this exercise, you will know how to:

Offset boundary edges of a surface. Create blended surfaces with curvature continuity. Check the Gaussian Curvature of a quilt.

ScenarioThe basic shape-defining surfaces of the mouse were created earlier. Since the mouse is a handheld device, the product stylist wants to smoothen the sharp edges with variable transitions. The transitions have been defined with the aesthetics of the product in mind.

Task 1. Locate and open the Mouse part.

1. Open the MOUSE.PRT. o Review the features in the part. o Rotate the model and view the underside.

Mouse Part

Task 2. Define the first two boundary curves for a blended surface by offsetting

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edges.

1. Offset the edge of the top surface.o Select the top surface and then select the edge of the surface, as

shown in the following figure.

Selecting the Edge

2. Click Edit > Offset.

o Edit the offset value to 0.3. o Select the Measurements tab from the dashboard.

3. Right-click in the tab and select Add to add another point. o Edit the Distance value of this point to 0.4. o Edit the Location value to 0.3.

4. Right-click in the tab and select Add to add a third point. o Edit the Distance value to 0.4. o Edit the Location value to 1.0. o Click Complete Feature .

Offset Edge on the Top Surface

5. Offset the edge of the front surface.

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o Select the front surface and then select the edge of the surface, as shown in the following figure.

Selecting the Edge

6. Click Edit > Offset.

o Edit the offset value to 0.3. o Select the Measurements tab from the dashboard.

7. Right-click in the tab and select Add.o Edit the Distance value to 0.4 and the Location value to 0.3.

8. Right-click in the tab and select Add.o Edit the Distance value to 0.4 and the Location value to 1. o Refer to the following figure. o Click Complete Feature .

Offset Edge on the Front Surface

Task 3. Define two additional curves through the end points.

1. Click Datum Curve from the feature toolbar.o Click Thru Points > Done.

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o Select the end points on the far left of the model, as shown in the following figure.

o Click Done.

Selecting End Points

2. Double-click Tangency.

o Select the edge shown in the following figure.

Specifying Tangency at the

Start Point

3. Click Flip > Okay.

o Select the edge shown in the following figure.

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Specifying Tangency at the

End Point

4. Click Flip and Okay.

o Click Done/Return. o Click OK.

Curve Created

5. Repeat the previous steps to create another curve through the far right end

points, as shown in the following figure. o Specify tangency at the start and end points, also shown in the

following figure. o Click Done/Return. Do NOT complete the feature yet.

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Specifying Tangency

6. Double-click Attributes.

o Click Quilt/Surf > Done and select datum plane TOP from the model tree.

o Click OK to complete the curve.

Curve Created

By changing the curve attribute from free to lie on the datum plane TOP, you have ensured

that the edge of the surface created will lie on the base of the mouse.

Task 4. Use the four previous curves to create a blended surface with tangency to the adjoining surfaces.

1. Start the Boundary Blend Tool from the feature toolbar. o Press CTRL and select the two curves in the first direction, as shown in

the following figure.

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Selecting Curves in the First Direction

2. Right-click and select Second Direction Curves.

o Press CTRL and select the two end curves in the second direction, as shown in the following figure.

Selecting Curves in the Second Direction

3. Select the Constraints tab.

o For Direction 1-First Chain, change the condition from Free to Tangent.

o Select the surface that the curve lies on for the tangency reference. o For Direction 1-Last Chain, change the condition from Free to

Tangent. o Select the surface that the curve lies on for the tangency reference.

4. Click Complete Feature .

Task 5. Merge the new blended surface with the original surfaces.

1. Change the selection filter from Smart to Quilts. 2. Select the boundary blend quilt created previously.

o Press CTRL and select the front quilt, as shown in the following figure.

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Selecting Quilts

You may notice that the merge feature will fail when selecting the combination of quilt side to

keep. This is because by default, the Intersect option is selected when merging quilts. You

need to use the Join option in this case.

3. Start the Merge Tool from the feature toolbar.o Select the Options tab and select Join. o Flip the arrow if necessary, as shown in the following figure. o Click Complete Feature .

Joining Surfaces

4. Select anywhere on the model background to de-select all items. 5. Press CTRL and select the remaining two quilts.

o Start the Merge Tool from the feature toolbar. o Right-click and select Join. o Flip the arrow if necessary, as shown in the following figure. o Click Complete Feature .

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Joining Surfaces

Task 6. Analyze the surface.

1. Click Analysis > Geometry > Shaded Curvature. o Query and select the entire quilt, as shown in the following figure. o Notice the Gaussian plot of the quilt shows that the geometry is

tangent (continuous in slope), but it is discontinuous in curvature.2. Select Saved as the Analysis Type.


Gaussian Curvature Analysis of Quilt

Task 7. Make the first two curves of the blended surface curvature continuous.

1. In the model tree, right-click Curve id 1016 and select Edit Definition.o Double-click Tangency. o Select the Curvature check box for the start point. o Click End and select the Curvature check box. o Click Done/Return. o Click OK.

2. In the model tree, right-click Curve id 1019 and select Edit Definition.o Double-click Tangency. o Select the Curvature check box for the start point. o Click End and select the Curvature check box.

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o Click Done/Return, and click OK. o The curvature plot should has not changed much since only the

boundary curves have been made curvature continuous.

Curvature Plot

Task 8. Redefine the surface and investigate the updated analysis.

1. Now that the boundaries have been made curvature continuous, we can make the surface curvature continuous.

2. In the model tree, right-click Boundary Blend 1 and select Edit Definition. o Select the Constraints tab. o For the Direction 1-First Chain, change the condition from Tangent to

Curvature. o For the Direction 1-Last Chain, change the condition from Tangent to

Curvature. o Click Complete Feature .

3. Notice the fringe pattern at the edges of the surface. o Zoom in and you will notice the color gradient changes near, but not

exactly on the boundaries of the blended surface. o The smooth blend of colors shows curvature continuity at the transition

surface.

Gaussian Curvature Analysis of Quilt

4. Save and erase the model.


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Exercise 3: Analyzing the Air Filter Cover (Challenge)ObjectivesAfter successfully completing this exercise, you will know how to:

Analyze the surface quality of a model using Surface Curvature and the Gaussian tools.

ScenarioYou have created an Air Filter Cover model using the Boundary Blend tool. You have found a number of small patches on the surface and removed them using the Blend Control Point option. You want to compare the surface quality before and after removal of the small patches.

Task 1. Review the surface quality of the model with many small patches.

1. Open the AIR_FILTER_COVER.PRT. o Select the main body of the model and notice the quilt has many

patches.

Air Filter Cover Model with

Small Surface Patches

2. Click Analysis > Geometry > Sections.

o Select the entire quilt, as shown in the following figure.

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Selecting the Quilt

3. In the Sections dialog box select the Definition tab.

o Right-click and select Direction Collector. o Select datum plane TOP from the model tree. o In the Sections area, type 10 for the number, 10 for the spacing and –

55 for the start value. o In the Plot area, type 20 for the Quality, and 10 for the Scale.

Surface Curvature Display

4. Zoom in and review the plots closely.

o Notice the breaks and jagged edges in the curvature plot, as shown in the following figure.

o Click Cancel Analysis .

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Closer View of the Surface Curvature Display

5. Click Analysis > Geometry > Shaded Curvature.

o Select the entire quilt to display, as shown in the following figure. o Zoom in and review the different shaded areas of the quilt. Notice the

various patches in the top left and right corners of the part. Also make a note of the minimum and maximum Gaussian curvature values.


Gaussian Curvature

Task 2. Review the surface quality of the improved model.

1. Open the AIR_FILTER_COVER_BLENDED.PRT. o This model is actually the same as the previous model, except that the

surface quality has been improved using the Blend Control Point technique (as shown in a previous exercise).

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o Select the main body and notice that the number of surface patches has been reduced, as shown in the following figure.

Air Filter Cover Model without the

Small Surface Patches

2. Click Analysis > Geometry > Sections.

o Select the entire quilt. o In the Sections dialog box select the Definition tab. o Right-click and select Direction Collector. o Select datum plane TOP from the model tree.

3. Zoom in and review the plots closely. o Notice that the curvature plot is continuous, as shown in the following

figure. o Click Cancel Analysis .

Surface Curvature Display

4. Click Analysis > Geometry > Shaded Curvature.

o Select the entire quilt. o Zoom in and review the different shaded areas of the quilt.

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o Notice the increase in continuity of the surface patches at the corners of the part.


Remember that Guassian Curvature only measures 2-directional curvature. In this model, only

the corners and sides curve in more than one direction, so only those show a color gradient.

Gaussian Display

5. Save and erase all models from session.


SummaryAfter successfully completing this module, you should know how to:

Define the need to evaluate the surface models. Describe the various surface analysis tools. Create and analyze curvature continuous surfaces.

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proe surfacing - module 9

Documents

air filter

objectivesafter

intersecting

line segments

click cancel

click complete

copy geometry

click complete