While textures can be applied to individual parts of many objects, as described in Applying a Texture to an Object, applying textures to an object’s class or classes may be more efficient. Texture resources can be assigned to a class, which in turn can be applied to objects during creation.
Walls and roof objects have their own class texture assignment tabs for the main textureable parts of these objects. (Additional parts can be textured individually from the Object Info palette.)
Curtain wall textures are determined by frame and panel settings, and cannot be set from the Render tab.
Roof faces, extrudes, sweeps, and floors contain additional textureable parts, but the Edit Class(es) dialog box does not make this distinction. Textures/surface hatches are applied by class like any other 3D object; see Applying Object Textures by Class. Apply textures to the individual parts of these objects with the Object Info palette and not by class.
Any components of the wall or roof, if textured by class separately from the wall or roof, are assigned textures from the Other tab of the Edit Class(es) dialog box.
Textures cannot be assigned to individual symbols directly through the Object Info palette. Textures must be applied to the separate components of the symbol. This can be done using the Edit Symbol command or by assigning textures to the classes that make up the symbol; complex objects can contain more than one class. Texture changes affect all instances of that symbol.
If you are modeling a glass object (glass reflectivity shader) with a 3D polygon or other sheet-like 3D object, duplicate and offset the 3D polygon by a small amount so that rays are traced through the glass with both an entering and exiting surface.
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