icon) for that property editor.
Editing Surface Shader Properties
An important part of the process of fine-tuning a scene is editing its shader properties. Most surface shaders have several properties in common. These properties are discussed in the following sections:
• Reflectivity, Transparency, and Refraction
Surface Shader Property Editors
Every shader is edited from its property editor. Property editors contain the various parameters that define the properties of individual objects, whether they be geometric objects, lights, or cameras. You can display and use multiple property editors simultaneously. For more information on property editors in general, see Modifying Properties in Property Editors [ Interface and Tools ].
Information about parameters listed in the property editor is available from its help topic (click the icon) for that property editor.
To open a shader property editor
1. Select an object in the viewport whose shader you want to edit.
2. From the Render toolbar, choose Modify > Shader.
The property editor opens in a floating window and you can now edit any of its parameters. Click the various tabs to select different parameter groups.
Other ways to open a property editor
• In the material manager, double-click on a shaderball in the shelf to open the shader property editor.
• In the explorer, locate the material of the object whose surface shader you wish to edit. Click the material’s icon to open its property editor. A combined property editor for the material and the surface shader opens.
• With the object selected, click the Selection button on the Select panel to display the selected object’s node.
Expand its material node and click the surface-shader icon beneath the surface node to open its related property editors.
• Select the object and open a render tree view. Double-click on the shader node you wish to edit.
• Select an object in a viewport or render tree view and press Enter. Choosing more than one object and pressing Enter displays the Multiple Selection property editor, which contains the objects’ common properties and shaders.
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If a parameter in a property editor is replaced with a question mark (?), this means that the parameter is being driven (controlled) by another shader. For more information on connecting a shader to a parameter, see Using the Connection Icon. |
You can create a very specific color for an object by defining its specular, diffuse, and ambient colors separately in the surface shader property editor.
• The diffuse color is the color that the light scatters equally in all directions so that the surface appears to have the same brightness from all viewing angles.
It usually contributes the most to an object’s overall appearance and it can be considered the “main” color of the surface.
• The specular color is the color of shiny highlights on the surface. It is usually set to white or to a brighter shade of the diffuse color.
Specular highlights are visible only on Phong-, Blinn-, anisotropic- and Cook-Torrance–shaded surfaces (see Shading Models). The size of the highlight depends on the defined Specular Decay value.
• The ambient color appears on areas that are shielded from light but are still visible due to an ambient light, which is a non-directional light that pervades the entire scene.
As an alternative to ambient light and color, you can use global illumination, which is more realistic but takes longer to calculate (see Global Illumination and Caustics [Indirect Illumination]).
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For more realistic results, you may want to make the Ambient color identical to the Diffuse color and let the Scene’s Ambient color control the ambient value. |
Deactivating Illumination Parameters
You can deactivate the Diffuse parameter, for example, when you set a specular and ambient value. Deactivating a parameter does not remove it from view. In the previous image, the Diffuse component would not become transparent.
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A deactivated illumination parameter is converted so that its R, G, and B values are 0 and its Alpha channel remains at 1. |
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