Introduction

To recap on last week’s lesson, look development or lookdev is the process of creating and refining the designs for characters and objects that are 3D modelled for a production such as a film or TV show.

Lookdev Scene

This is an example of a lookdev scene:

The grey ball is to show how the lighting being used would affect a standard untextured Maya asset and the chrome ball shows the HDRI lighting map that is being used for the scene.

The Macbeth colour chart allows the creator to calibrate the colours in the scene and to see how the colours look under the lighting of the scene.

Shaders

A shader is a material that is applied to a 3D model that changes how it looks. The official definition is that “A shader defines how to compute each pixel in an image during rendering”. The design of shaders can be different according to which rendering engine is used, but they are all built with similar settings and types (e.g diffuse, specular and normal).

PBR Workflow

PBR stands for Physical Based Rendering. Most VFX and games companies use a PBR workflow.

This means that objects that use shaders behave as they would in real life – glass, water, bricks or metal are all affected by light in the same way that they are in real life, or as closely as possible.

PBR uses a texture map image for each shader component.

This saves time for artists, meaning that they don’t have to input each and every value into a shader.

Components of a Shader

• Base/Diffuse – This is the colour of the shader
• Specular/Metallic – This is how reflective a surface is.
• Roughness- This determines how smooth a surface is, and how defined the reflections are.
• Transmission – This is how much light is diffused through an object.
• Subsurface – This is the light scattering
• Translucency -The ‘Alpha’ of a model, how transparent it is.
• Emission/Incandescence – This is how much light an object emits.
• Normal/Bump/Displacement – 3D detail.

Leaf Properties

We started the process of shading/texturing a leaf by describing the physical properties of a leaf:

• They have a glossy, smooth surface.
• There is a wide range of green colours on a leaf, not just one shade.
• Leaves allow some light to pass through them. They are semi-translucent.

Subsurface Scattering

Semi-translucent materials are affected by an occurrence of light sub-surface scattering. This is where light waves, rather than only reflecting off of the object, also go into the object and bounce around inside of the object, changing its colour.