caustics research

Francois Mangion, Shuchi Agarwal, Ran Yan, Ali Zolfaghari (Bartlett School of Architecture RC2)

PORTFOLIOBY TEAM CAUSTICS

why?[Analysing light as architecture]

These images are the refraction patterns formed when light asses through various shaped and formed plastics, glass or liquid. By careful control and manipulation of the forming process, semi-regular patterns and delicate tracery can be achieved.

The effects we studied are determined mostly by basic geometric shapes and small un-dulations of surface topography which when illuminated under specific lighting produce amazing caustic effects. Although artists have projected such patterns in the past onto screens and walls, there has been little experimentation using photography and digital simulation.

All our research work has been on practical experimentation with digital simualtion backing and the evaluation of hundreds of objects either found or created. The most important part of the system to show these patterns is light which was feeding us all sorts of caustic pat-terns for us to explore, develop and expand in the field of architecture.

RC2_Choreography of light

1. Why?

2. The Caustic Analysis 2.1. Analogue Analysis 2.2. Digital Analysis

3. Evolution of Caustics

4. Physical Analysis 4.1. Layered Models 4.2. Surface Deformation

5. Caustic Networks 5.1. Composition of 3D shapes 5.2. Surface Deformation

6. Archiglace

RC2_Choreography of light

CONTENTS

ANGUE

ALO Analogue analysis of refraction patterns formed when light passes through various shapes and everyday objects made of plastic or glass. By controlling and manipulation of the direction of light, ori-entation of objects and different types of light sources we started forming semi-regular patterns and delicate tracery.

Also the integration of liquid and coloured plastics into the tested objects, modifi es the way the plastic refracts light and hence the associated varies. Here we are using digital cameras to capture the light projected by the object itself onto a screen surface.

SURFACE ANALYSISCAUSTICS ANALYSIS THROUGH CUP (CIRCLES)

Below_ Caustic pattern projection from a patterned glass cup using a white directional light source.

1. Close-up of initial surface analysis of patterned glass caustics 2. Detailed close-up of light caustics

3. The integral caustic pattern project-ed from the tested patterned glass.

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1. The integral caustic pattern project-ed from the tested patterned glass.

2. Close-up of initial surface analysis of patterned glass caustics 3. Detailed close-up of light caustics

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SURFACE ANALYSISCAUSTICS ANALYSIS THROUGH COLOURED PLASTIC

Below_ Caustic pattern projection from a patterned glass cup through liquid & coloured plastic.

1. Caustic interaction of analysed glass surface & coloured plastic.

2. Close-up of the projected caustic pattern projected by the 2 surfaces.

3. Photographic analysis of multi-ple mayers of materials. Glass-Liq-uid-Coloured Plastic

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DIGITAL

Most modern rendering systems support caustics. Some of them even support volumetric caustics. This is accomplished by ray-tracing the possible paths of the light beam through the analysed material, accounting for the refraction and refl ection.

Photon mapping is one implementation of this. The focus of most computer graphics systems is aesthetics rather than physical ac-curacy and hence we are using a computer generated tool, usu-ally appreciated for its aesthetic characteristics, to obtain a more accurate and analytical study.

Some computer graphic systems work by “forward ray tracing” wherein photons are modeled as coming from light source and bouncing around the environment according to rules. Caustics are analysed through basic geometric shapes of curvature and recording the shift in the projected caustic curves, position of ob-ject, light source and angle of incidence. In the region of study suf-fi cient information is recorded to further understand what shapes give which type of caustic curves, determining if there is a direct path to the light source and how this changes.

SIMULATION

DIGITAL SIMULATIONBASIC SHAPE BASED RESEARCH

1. CYLINDER

2. SPHERE

3. CRESCENT

Side

Position A

Position B

Position B

Side

Position A

Position B

Side

Position A

Position B

Side

Position A

Position B

4. CONE

6. RHOMBIC

Position A

Position B

Position C

Light Position 1

Elevation

Plan

Position A

Position B

Position C

Light Position 1

Elevation

Plan

Position A

Position B

Position C

Light Position 1

Elevation

Plan

Position A

Position B

Position C

Light Position 1

Elevation

Plan

5. ELIPTIC

Sid

e

Sid

e

Plan

Posi

tion

1

Posi

tion

1

Posi

tion

2Po

sition

2

Posi

tion

3

Plan

Sid

e

Sid

e

Plan

Plan

Posi

tion

1

Posi

tion

1

Posi

tion

2

Posi

tion

2

Posi

tion

3

7. LANCEOLATE

8. OVATE

Side

Side

Plan

Plan

Position 1

Position 2

Position 3

Position 4

Position 1

Position 2

Rotate X Rotate Z

PlanFront

Change Position

9. CUNATE

Position A

Position B

Position C

A Position B C

Plan

Front

Position A

Position B

Position C

A Position B C

Position A

Position B

Position C

A Position B C

Plan

Front

Position A

Position B

Position C

A Position B C

10. SPATUALTE

11. TORUS

Rotate Y

Plan

Front

Change Position Rotate Y

Plan

Front

Change Position

Rotate Y

Plan

Front

Change Position

Position A

Object Position 1

Plan

Elevation

Light Position 1

Light Position 2

5. LINEAR

Side

Side

Plan

Plan

Position 1

Position 2

Position 3

Position 1

Position 2

SHAPE ANALYSISCAUSTIC SIMULATION OF LINEAR SHAPE

Position C

Position A

Position E

Position B

Position D

Position APosition E

PlanSide

Position C

Position A

Position E

Position B

Position D

Position APosition E

PlanSide

SHAPE ANALYSISCAUSTIC ANALYSIS OF RENIFORM SHAPE

12. RENIFORM

Object Position 1

Elevation

Position A

Position B

Position C

Plan

Light Position 1

Light Position 2

Light Position 3

Object Position 1

Elevation

Position A

Position B

Position C

Plan

Light Position 1

Light Position 2

Light Position 3

SHAPE ANALYSISCAUSTIC ANALYSIS OF STAR SHAPE

13. STAR

SHAPE ANALYSISCAUSTIC ANALYSIS OF HASTATE SHAPE

15. HASTATEObject Position 2

PlanElevation

Light Position 1

Light Position 2

Light Position 3

Object Position 2

PlanElevation

Light Position 1

Light Position 2

Light Position 3

EVO ON

LUT

Using computer simulation, caustic curves are mapped and analysed through a consistant shifting of both the x and y-planes.

The basic geometric curves are recorded, the shift in the projected caustic curves, position of object, light source and angle of incidence are recorded. In the re-gion of study suffi cient information is recorded to further understand the evolution of caustic surves, determining if there is a direct path to the light source and how this changes with distance.

ofCAUSTICCURVES

SHIFT ANALYSISCAUSTIC CURVE EVOLUTION FOR STAR SHAPE

TILES LAYOUT 1

SHIFT ANALYSISCAUSTIC CURVE EVOLUTION FOR RENIFORM SHAPE

TILES LAYOUT 1

SHIFT ANALYSISCAUSTIC CURVE EVOLUTION FOR HASTATE SHAPE

PHY AL

SIC

Each individual layer of plexi glass is cut into a geometric shape representing the caustic pattern recorded. When put together they create a gradation in shape with each level of the composition. The construction motivates the viewer to walk around it to see how it is built and how the additive elements on one side create the depth on the other. The model together becomes a study of light as a volume in space. The geometric shapes become a changing illusion three dimensionally.

ANALYSIS

layered models

PHYSIC

layered models

PHYSICAL ANALYSISLAYERED MODELS

CAUSTIC CURVE EVOLUTION

Caustic curve evolution

1. Layering model used to analysing the evolution of the caustic curve. 2. Close-up detail of the caustic curve development.

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1. Side view of the layered model showing clearly the caustic curve transition.

2. Front view of the layered model showing clearly the caustic curve transition.

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PHYSICAL ANALYSISHOLOGRAM MODEL

Caustic curve chosen to generate the hologram

Graphical representation of hologram

Graphical representation of hologram

1. The hologram model showing the volumetric qualities of a caustic curve.

2. Side view of the hologram model

3. Front view of the hologram model1

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PHY AL

SICWith the aid of grasshopper, the analytical caustic curves were used as deformers hence obtaining a 3 dimen-sional representation of the light curve itself which, in turn, gives us the ability of further analysis.

ANALYSIS

surface deformation

PHYSICAL ANALYSISSURFACE DEFORMATION

SURFACE DEFORMATION_1 SURFACE DEFORMATION_2 SURFACE DEFORMATION_3 SURFACE DEFORMATION_4

Plaster Mould for Glass Casting Plaster Mould for Glass Casting Plaster Mould for Glass CastingPlaster Mould for Glass Casting

Milled Surfaces generated from the caus-tic curves, used to produce plaster moulds for the glass surfaces.

1. Initial assembly of the milled surface mould for the plaster.

2. Moulds ready to be fi lled using a mixture of plaster & quartz.

3. One typical plaster mould to be used for the glass surfaces.

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1. Plaster moulds with glass powder & granules, placed in the kiln ready to bake for 60hrs

2. Internal view of the kiln and moulds using 2 types of recy-cled glass; powder & granules.

3. Breaking of the plaster moulds to remove the glass surface after 60hrs of baking.2

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The resultant glass surfaces to be tested , showing clearly the fun-damental resulting difference be-tween the powder and the granu-lated glass.

1. Glass surface 1

2. Glass surface 1 tested over light (showing an inverted representation of the caustic curve they were gener-ated from)

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1. Glass surface 2


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1. Glass surface 3


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1. Glass surface 4


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NETWORKS

Using digital simulation and analogue analysis, custic net-works are created and analysed through 2 basic meth-ods of analysis.

1. Combination of 3D shapes2. Direct Surface Deformation

The basic geometric caustic curves are recorded de-pending on the surface generated from. In the region of study suffi cient information is recorded to further under-stand the transition of caustic curves, determining if the end result was direct combination and repetition of caustic curves or if a proper caustic network was generated.

CAUSTIC

ANALYSIS

CAUSTIC NETWORKSCOMBINATION OF 3D SHAPES

3D shape combination network testing

Network combination of crescent shape

resultant caustic patterns [not caustic networks]

Network combination of crescent shape

1. resultant caustic patterns gen-erated from a combination surface [not caustic networks]

2. resultant caustic patterns gen-erated from the rotated combina-tion surface [not caustic networks]

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CAUSTIC NETWORKSSURFACE DEFORMATION_ CIRCULAR BUMPS

Network of surface with circular bumps

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CAUSTIC NETWORKSSURFACE DEFORMATION_ MULTI-DIRECTION BUMPS

Network of surface with bump in 2 directions

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CAUSTIC NETWORKS CAUSTIC NETWORKSSURFACE DEFORMATION_ ALTERNATING BUMPS SURFACE DEFORMATION_ SPIKES

Caustic networks projected from alternating bumps surface Caustic networks projected from alternating bumps surface

MATERIALRESEARCH

MATERIAL ANALYSISICE CAUSTIC ANALYSIS

Rectangular Ice Surface(120mm x 300mm x 25mm)

1. Initial testing of light caustics in ice

2. The thin tile of ice tested for light caustics generated.

3. Close-up view of ice caustics.

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Connor O’Grady, May Wu, Emad Ghattas (Waterloo Architecture)

MUSéE NATIONAL DES BEAUx-ARTS DU QUéBEC

ARCHIGLACEBY TEAM CAUSTICS

Modulated ICE_SURFACE was created by students from RC2 (UCL Bartlett School of Architecture) and Waterloo University collaboration in Canada by Francois Mangion, Shuchi Agarwal, Ran Yan, Ali Zolfaghari (Bartlett School of Architecture RC2) and Connor O’Grady, May Wu, Emad Ghattas (Waterloo Architecture)

The project’s scope was a full-scale ice installation that transformed the traditional ap-proach towards the application of ice in architecture. Part of Archiglace (a.k.a. Inclusions) at the (MNBAQ), in association with the Quebec Winter Carnival, Caustic ICE_SURFACE explores ice as a primary construction material. The installation seeks to enhance and transform the visitor’s expectation of ice application through visual conditions of fi guration, lighting, materiality, texture, possible coloration, and corporeality. Revealed only through a single opening in the museum corridor, the installation accompanies the visitor’s visual background along a walk through all the other installations, gently lifting vertically from the yard’s ground, and undulating as the ornamented foreground of the old Museum’s internal Façades. The project sensitively engages occupants through its formal description of prox-imal and cuspate peaks while elegantly dissipating into the surrounding snow at its edges.

ICE_SURFACE

2013

CATICS

USFinding a way to build incredible structures using just ice. In an at-tempt to find light caustics with ice structures this practice led to specific technique of working exclusively with “tiles” of frozen water. The enchant-ingly frosty structure start off with only 4 different types of frozen “tiles”.

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Above_ Initial visual proposal

The design investigated both, the abstract mathematical constructions of undulating surfaces, and the rich tectonic and ornamental potential of the fascinating yet contradicting versatility and “uncontrollable” nature of ice, hence fully embracing its seductive and surrealist attributes.

In doing so, the design aimed at generating a new definition of superficial interiority in architecture by articulating a loose and modulated network that challenge the conventional divisions of wall and ceiling, surface and space, monolithic and discrete, opaque or clear, monochrome or coloured, figure and figuration.

As a Digital Fabrication Studio, Team Caustics as part of RC2 was concerned with developing this ice project throughout all phases of design, fabrication and installation including the development of a coherent tectonic and as-sembly system, intricate detailing and affluent materiality.

Right_ Analysis of light caustic patterns projected using ice

PRODE

SIG

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DEV

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PMEN

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The fi rst proposal for Modulated Surface was a result of an in-vestigation into surface development through the use of only four modulated ice tiles with varying curve degrees which when fi t together would create uni directional waves of varying heights. This digital to analogue feedback was aimed in cre-ating a platform to advance segmented fabrication processes ensuring the completion of the installation while preserving all of the desired design ideas.

Above_ First Modulated Surface proposal without a sub-structure; linear directional undulations.

Above_ Initial proposal included a waffl e sub-structure to help support the ‘tiled’ overall surface

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CAST

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SSEM

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CONSTRU CTION

The Modulated ICE_SURFACE final installation is comprised of four unique tiles types; totalling 90 tiles fabricated using cus-tom designed moulds. All of these four modules are square in shape with inter dependency through their flexible rotational and mirroring logic. Once aggregated, these four tiles form a larger meta-tile [40cm X 40cm], which is then duplicated and rotated to systematically grow into a larger field condition based on the concept of self supporting dome structures.

FABRICATION LOGICCOMPRESSIVE ICE TILE CONSTRUCTION

Experimental ICE tileTraditional ICE cube

Thickness: 20mm

FABRICATION LOGICONDULATED SURFACE LAYOUT

TILES LAYOUT 1 TILES LAYOUT 2 TILES LAYOUT 3

FINAL TILES LAYOUT

Layout Plan Layout Plan Layout PlanLayout Plan

TILES ORGANISATIONMODULES SCHEDULE

MODULE A MODULE C MODULE DMODULE B

Size: 220 x 220mmThickness: 20mmCurvature: 130mm




Above_ Process of Fabrication of the Moulds used to make the ice tiles.

TILES ORGANISATIONMODULES LAYOUT

A B C D

Above_ Tiles Aggregation: Individual Tiles Layout

The tessellation of the surface modules is further enhanced by achiev-ing the thinnest thickness of the ice possible for the eventual surface to be self-supporting. This coherence approach in size and thickness creates a sense of continuity in the fi nished surface.

ICE_SURFACE consist of a fi nite number of tiles each of them with a distinct curvature yet interdependent,the tiled surfaces are not textured yet the subtle natural crystallization pattern within the ice itself affects the overall fi nished surface. This aspect of inner crystallisation of ice was made possible by the rapid freezing process of the tiles inside a freezer. Customized techniques and methods of coloration were ana-lysed but not implemented to further defi ne the abundant material effect of these thin ice tiles.

ASSEMBLY LOGISTICSLAYERED CONSTRUCTION

ICE_SURFACE structure consists of a centralized cross-arc spine suspended from the ground on four sides; with transverse perpen-dicular appendages further supporting the load distribution in the tiling. This structural logic, paired with the minimal thickness of the modules allows the construction to calibrate temporary supports designed as boxes that were used for the initial moments of as-sembly and removed once the joints were adequately frozen.

Step A

Step C

Step B

Step D

Left_Laying the tiles illustrated in Step A to form the foundation of the cross-arc spine.

Right_ Continuation of assembly using temporary framework as boxes for support.

Initial testing of different methods of as-sembly for the moulds was done to de-termine the most viable and time effi cient method.

These pictures illustrate the steps taken to make one ice tile.

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1. Assemblage of the top and bottom parts of the vaccuum formed plastic moulds was done by adding screws at equal intervals on all four corners to hold the two pieces together.

2. Silicone was applied only onto the top pieces of the moulds to allow for the moulds to be disassembled easily and be reused.

3. Clay was used on the edges of the assembled moulds to make it water tight. The moulds where then put into the freezer for around 6 hrs to make the ice tiles.

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1. The process of making the card-board boxes with unique curvatures on the top; The curvature illustrated comes from the study of intercon-nections between four tiles at the point of placement of the box.

2. The placement of the four card-board boxes was pre-determined at equal distances according to the design of the surface. To make them reusable, duct tape was ap-plied as a waterproofi ng method.

3. The moulds of each ice tile con-sisted of two halves. The top and bottom half which fi t together to create one module. The picture displays the method used to make the moulds water tight by using sil-icone.

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Photography_ May W

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Since each tile’s relation with the next was based on edge conditions, it be-came exceedingly important to get perfect edges for each tile.

The four edges of each tile of ice was cleaned using a method of melting. Using a heated piece of metal, the ice was melted until clean edges of ninty degrees were acquired.

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1.Individual ice tiles were connected by ‘gluing’ them together using snow and water. The gaps were fi lled with snow and hot water was poured over it to melt the two edges into one unit.

4.For additional temporary support, snow walls was constructed along the cantilevered edges of the tiles. All the snow was removed once the assem-bly of the surface was complete

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The success in the construction of the ICE_SURFACE exemplifs the premise that the usage of only ice as a material for construction is feasible with the extensive study and experimentation between the design and properties of ice.

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Connor O’Grady, May Wu, Emad Ghattas (Waterloo Architecture)

ARCHIGLACE

MUSéE NATIONAL DES BEAUx-ARTS DU QUéBEC

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caustics research

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