1

4.206

Design Computing

Computer Rendering& Radiosity

Lecture 5

1. Lighting – Day Light

2. Radiosity Modeling

3. Louis Kahn

4. Design Options with Radiosity

SOLID MODELING

1D TEXT INFORMATION

2D DRAWINGS

3DMODELS

RENDERINGS

ANIMATIONS

2D CUTTING

3D PRINTING

INFORMATION IN

INFORMATION OUT

Design Input & Output High Level Rendering

• Building of a Stage Set

• Relationship between Lighting & Surfaces

2

3D Computer Rendering

Rendering with Light

• Providers of Light

• Present Design Possibilities

• Define Designers Thoughts

• Natural Lighting – Day Light

LIGHT

Day Light

r = Angle of Reflection

Artificial Light

r = Angle of Reflection

LIGHTING TYPES

Diffuse Light - Bouncing Rays

Direct Light - Vectors

Surface Value - B

Surface Value - A

Surface Value - C

LIGHTING TYPES

Diffuse

LIGHTING TYPES

Direct

SURFACES

Direct Light - Reflections – View Dependent

Reflection

Spread

Transparency

i =Angle

ofInc

idenc

e

l

r = Angle of Reflection

SURFACES

Reflections – View Dependent

Norm

a

SURFACES

Types of Reflections

Specular Diffuse Spread

3

n sin (0) in (0’)

0’

0

SURFACES

Transparency - Refraction

Refraction

SURFACES

Transparency - Refraction

Air

N = 1

Glass

N’ =1.5

= n’ s

i

r

ic

SURFACES

Partial Transparency - Refraction

Air

N = 1

Glass

N’ =1.5

SURFACES

i

SURFACES

Diffraction

Diameter of hole

SURFACES

Interference

4

5

SURFACES

Interference

Dielectric

Glassy Layer

Glassy Layer

Design

PLAN

Locations of Windows

Building Orientation

S

EW

N

BUILDING PLANNING

SECTION

Openings

Height of Windows

Radiosity

• Simulating Global Illumination

• Calculates Global Energy Loads

• Final Results can be raytraced

• Day Light & Artificial Light

• CAD Models are Stage Sets

RADIOSITY PROCESSING

1) CAD FILE – AutoCAD

2) Preparation of Materials

3) Radiosity Model

4) Final Images - Raytraced

CAD Model

TranslationFile

RadiosityModel

Final Rendering

Walls

Floor

Ceiling

Furniture

Light

CAD MODEL

Models should be a trimmed version of the original model (Stage Set)

Surfaces should not touch

Radiosity works best with enclosed spaces

i

Lighting

Geometry Layers

Mater als

PREPARATION OF MATERIALS & LIGHT

Geometry

VIEW

VIEW SOLUTION FILE

ENERGY ON SURFACES FINAL SOLUTION

6

CAD ModelCAD Model

CAD ModelCAD Model

Raytraced

(A)

Raytraced

(B)

Raytraced

(C)

Raytraced

(D)

Raytraced

(A)

Raytraced

(B)

Raytraced

(C)

Raytraced

(D)

Assignment #5

Radiosity Model

Image

Analysis 11AM – Feb. & 12PM June

Image Image Image

CAD Model

Radiosity Model

Image

Solution 2PM – June

Image Image Image

CAD Model

7