3D layers have Material Options properties, which determine how a 3D layer interacts with light and shadow.

Casts Shadows

Specifies whether a layer casts shadows on other layers. The direction and angle of the shadows are determined by the direction and angle of the light sources. Set Casts Shadows to Only if you want the layer to be invisible but still cast a shadow.

Use the Only setting and a non-zero Light Transmission setting to project the colors of an invisible layer onto another layer.

Light Transmission

The percentage of light that shines through the layer, casting the layer’s color on other layers as a shadow. 0% specifies that no light passes through the layer, casting a black shadow. 100% specifies that the full color value of the shadow-casting layer is projected onto the layer accepting the shadow.

Use partial light transmission to create the appearance of light passing through a stained glass window.

Accepts Shadows

Specifies whether the layer shows shadows cast on it by other layers.

Accepts Lights

Specifies whether the color of a layer is affected by light that reaches it. This setting does not affect shadows.

Ambient

Ambient (nondirectional) reflectivity of the layer. 100% specifies the most reflectivity; 0% specifies no ambient reflectivity.

Diffuse

Diffuse (omnidirectional) reflectivity of the layer. Applying diffuse reflectivity to a layer is like draping a dull, plastic sheet over it. Light that falls on this layer reflects equally in all directions. 100% specifies the most reflectivity; 0% specifies no diffuse reflectivity.

Specular

Specular (directional) reflectivity of the layer. Specular light reflects from the layer as if from a mirror. 100% specifies the most reflectivity; 0% specifies no specular reflectivity.

Shininess

Determines the size of the specular highlight. This value is active only if the Specular setting is greater than zero. 100% specifies a reflection with a small specular highlight. 0% specifies a reflection with a large specular highlight.

Metal

The contribution of the layer color to the color of the specular highlight. 100% specifies that the highlight color is the color of the layer. For example, with a Metal value of 100%, an image of a gold ring reflects golden light. 0% specifies that the color of the specular highlight is the color of the light source. For example, a layer with a Metal value of 0% under a white light has a white highlight. (If you are using OpenGL, the Metal value is temporarily set to zero during an interactive preview.)