Shader Graphs

Toy Story, Pixar. 1995First computer generated, full length film. Phong Reflectance Model

Material Surfaces are complicated.

dMaterial color k is no longer constant.

k changes based on angle to the surface.d

Examples

Iridescence

rough smooth rough

Specular power n is no longer constant.

Specularity changes based on position on the surface.

e.g. Wet skinWater is smooth in places,dry skin is rough in others.

1984

Examples

Material color k is no longer constant.

k changes based on position on the surface.

d

d

Maya Hypershade

Phong nodeChecker node

Plant Shader

Maya Hypershade

Mental Images, MentalMill

Lab:

Maya Hypershade

Override button.Replaces a constant variablewith a texture/node.

Notice that essentially ANY attribute can get an override. Very powerful control.

Getting to Hypershade

Very useful. Show graph for selected object.

When you override a graph isautomatically created.

Three variablesare overridden

Three variablesare overridden

Best view:See the hypershade (left), viewport object (middle), and attributes (right)

Lab:

1) Find a material you would like to render. (use a sphere)

2) Do research, or think carefully on the material, to find out what makes it look that way.

3) Create a hypergraph which approximates the material.

Note: Writing shaders is an art, it takes practice and experience to know which variables to override, and how to create the shader graph.

Some examples: Fabric, skin, copper, cloth, …