Incidence

Category: Illumination

Shader Family: Texture

Output: Scalar

Shades the edges of an object or define an arbitrary shading direction based on light or on the angle of the surface relative to the camera, one or more lights, or a vector.

When used with various surface shaders, the Incidence shader defines variable transparency, for example, on a glass object so the edges appear more opaque than the center. Other possible applications are an X-ray look, static blur, varnish, or glass transparency.

Name	The shader's name. Enter any name you like, or leave the default.
Mode	Camera/Lights: uses the system light list (all the lights in the scene, including exclusive and inclusive light support) Camera/Lights (Light List): uses a specific light or set of lights to compute the incidence. Surface/Light: uses the system light list (all the lights in the scene, including exclusive and inclusive light support) Surface/Lights (Light List): uses a specific light or set of lights to compute the incidence Surface/Camera: computes incidence based on the angle of the surface normal, relative to the camera. Perfect for glass and x-ray type shading. Surface/ Vector: computes incidence based on the angle of the surface normal, relative to a custom vector. X Up Axis: Use vector value (1, 0, 0) X Down Axis: Use vector value (-1, 0, 0) Y Up Axis: Use vector value (0, 1, 0) Y Down Axis: Use vector value (0, -1, 0) Z Up Axis: Use vector value (0, 0, 1) Z Down Axis: Use vector value (0, 0, -1)
Light List	This control is displayed when the incidence mode is set to any mode that uses a light list. Use it to select the lights that contribute to the incidence computation. For more information, see Using Light Lists [Direct Illumination].
Shading Range	Controls the range of shading over the object's surface. 90-Degree: When the shading range is set to 90 degrees, the shading effect is only visible where the surface of the object is pointing towards the light. 180-Degree: When the shading range is set to 180 degrees, the entire object surface is available to the shading effect.
Illuminance	When enabled, light incidence is multiplied by light intensity.

Modify

Invert	Inverts the variation in the shading created by this shader. For example, if the shading is darker at the edges of the shaded object than at its center, inverting it will make it darker at the center than in the edges.
Bias	Controls the contrast between dark and light areas of shading. Values below 0.5 create larger dark areas, values above 0.5 create larger light areas.
Gain	Controls the brightness of the effect.

Render Tree Usage

Usually used at the end of a render tree (left side), this shader often needs to be used in conjunction with a few other shaders to obtain results. These shaders are:

Connecting this shader to the Transparency input of a surface shader and setting the Mode to Camera/Surface is the best way to achieve glass-like results.