Project 2 Help Session : Shading

The basic info on shading is covered in Learning Alias, the Shaders and Textures section and lessons 9-10. Unlike the modeling tutorials, this material doesn't take long to go through.

Interface

Throughout the shading sections, the book instructs you to open the Multi-Lister and choose Shaders from a menu. In the version of Alias that we have, choose Windows->Multi-lister->Shaders....

Shading models

Each shading model is named after the graphics person who developed it. Don't worry about the details of these models. They basically work well for different types of materials:

Lambert -- matte and unpolished surfaces
Phong -- glass and glossy surfaces
Blinn -- reflective metals
Lightsource -- don't use this

The shading parameters vary according to the model chosen. Focus on tweaking the following parameters:

Lambert
- Diffuse -- how much light is reflected from surface
- Color -- as you know it
- Incandescence -- color of unlit parts of surface (corresponds to ambient color)
Phong
- Diffuse
- Color
- Incandescence
- Specular -- color and intensity of specular highlight (intensity is implicitly controlled by color value)
- Shininess -- size of specular highlight
- Reflectivity -- degree to which surroundings are reflected
- Transparency -- color and amount of transparency (as with Specular, amount of transparency is implicitly controlled by color)
Blinn
- Diffuse
- Color
- Incandescence
- Specular
- Reflectivity
- Specular Rolloff -- parameter which controls the effect of increasing reflectivity at oblique angles
- Eccentricity -- size of specular highlight (unlike Shininess only in that slider works in opposite direction)

Texture mapping

Alias provides three texture mapping tools:

parametric mapping -- texture mapping as you know it
solid projections -- various ways to cheat at achieving a solid texture effect
real solid texture mapping, in which a model is "carved out" of a solid block of texture

Rendering

Read lesson 12 in Learning Alias to get the basics of rendering. If your scene has reflective or transparent objects in it, be sure to use Raytracing instead of Raycasting. Choose Raytracing or Raycasting using the option dialog for Render->Render.

The rendered images go into the pix directory of the current project. You can view an image that is rendering or was just rendered using Render->Show render.