Working with Materials

Shader Types

There are four shader types: Standard, Simple, Shadow Matte, and No Shade.

To select a shader type:

1. In the Materials UI, select a shader:

• Standard The full range of parameters for creating diverse 3D effects using lights and cameras.
  
• Simple A subset of Standard shader parameters. It does not consider lights in the scene, but you can create lighting effects using environment maps.

• Shadow Matte Used to blend shadows into a scene. By adding objects to a scene, you can create realistic shadow effects.

• No Shade Lets you set parameters and texture mapping for the main material channel only. You rely on the lighting effects in the source image to provide illumination.

Basic Shading Parameters

The basic shading parameters let you set a layer's opacity. Depending on the shader type selected, you can also set the refractive index and surface glossiness.

To set basic shading parameters:

1. Enter a value for the object's opacity, refractive index, and glossiness.

Opacity

Sets the transparency for the layer. Values are measured in percent. A value of 100 is opaque, a value of 0 is transparent. If you want to create a transparent surface, such as glass, a low value (10) will yield a more convincing result than 0.

Note Transparency affects the visibility of a layer's other attributes.

Glossiness

Sets the level of glossiness for the layer, which affects the specular highlights created when a light shines directly on a layer. A glossier, more reflective surface yields a smaller, sharper highlight. A less glossy surface has a highlight that is more diffuse or blurry. Glossiness is available with the Standard shader only. Values range from 0 to 1, with a value of 1 being completely reflective. In this case, you would not be able to see any of the objects other surface properties, so glossiness should be set to less than 1.

Setting Material Colors

You can set color factors for each texture channel available for the type of shader you select. If you are working with a Standard shader, you can also set color factors for ambient and specular lighting effects. The colors you set are multiplied with the colors of the input source image connected to that channel. The Shadow Matte shader has no color factors. For a description of material color settings, see Material Color Settings

To set material color values:

1. Click the color pot of the channel that you want to set a color.

   The Color Picker is displayed, so you can set color values—see Color Picker.

Using Texture or Environment Maps to Control Surface Attributes

The Main texture channel defines the surface's general appearance, but if your main texture is not enough to give you the look you want, you can add more texture maps. Each Material node has five texture channels that you can use to apply texture and environment maps to refine the appearance of an object's surface. You can set parameters for each channel.

The Main and Bump texture channels let you wrap and position a texture on the surface. By default, the image is clamped to the surface. You can then use placement parameters to position the source image on the surface and apply tiling effects.

The Radiosity, Reflection, and Refraction channels let you apply environment maps to your surface object. The environment maps use their source image to surround the surface with a virtual sphere to simulate an environment, which shows up as reflections on the surfaces of objects with reflective properties. The environment map always covers the sphere exactly once. You can transform your object and see the effects of the environment map change dynamically. Using environment maps is a fast and inexpensive way to achieve highly realistic lighting effects.

To connect a source image to a texture or environment map channel:

1. Do one of the following to display the Group Schematic:
   • In the Schematic view, double-click the Reaction tool.
   • In the Schematic view, right-click the Reaction node and select Edit Group.
2. Connect a source image node to a channel tab on a Material node. To identify the nodes, pause over a material node to see a tooltip with the node name.

   Material Texture Channel	Description
   Main	The main channel is used to apply a source image as a texture map on a selected object's surface. You can position the material on the surface using the UV placement controls, and tile the image in U and V.
   Reflection	A reflection map uses the source image to create realistic reflections. You can use the color factor to set areas and the degree of reflectivity for the material. You typically set a grayscale color value, with white being completely reflective, and black having no reflectivity. You can, however, achieve tinted reflections by set setting a color.
   Refraction	A refraction map is an environment map that can be used to simulate how light traveling through a refractive, transparent material is distorted.
   Radiosity	The radiosity map uses the source's color and luminance values to add radiosity effects to the layer surface.
   Bump	A bump map is usually a different image that you specify as a source for a bumpy or textured appearance on a surface. It is sensitive to light sources. Its RGB (when using an RGB image, it is a normals map) or luminance values are used to simulate relief on objects by perturbing the surface shading according to an image map. The geometry is not affected.

3. To exit the Group Schematic, double-click anywhere in the Schematic.

To set texture and environment map parameters:

1. In the Materials UI, select a layer from the Layer Editor.
2. Select the Simple or Standard shader.
3. Under Channels, select a channel: Main, Radiosity, Reflection, Refraction, or Bump.
4. Adjust the parameters to control image brightness and texture quality, and in the case of the Main and Bump textures, specify how the texture is positioned on the object. For a list of parameters, see Shaders Parameters