 INCIDENT blends between two parameters, based on the angle between the camera (or view
vector) and the surface normal.
How Does It Work?
INCIDENT interpolates between two colors, two percent values, or two distinct bump patterns. It does
this by calculating the angle between a camera view vector and the surface normal. The result is an incident angle which is then used to blend between Edge and Facing values.
The Pitch and Heading parameters cause INCIDENT to behave as though the normal to the surface is bent up or down (Pitch) or to either side (Heading).
Hints!
INCIDENT is excellent for creating x-ray or microscopic (electron microscope) looking surfaces. Figure F2
below shows an example of how to do this. The DarkTree Shader is set to full Luminosity and to zero Diffuse and Specular shading.
Below are more Incident examples. Silk uses a Bell function to get an off center brighter color in the
shading. Ghost increases transparency towards the edges. Titanium increases the coloration towards the edges. Water shows increasing reflectivity as the view angle increases. Incident can greatly increase the
realism of many surfaces or, if you like, make very unreal surfaces.
Note: Using a bitmap of a DarkTree with INCIDENT in it to texture a 3D model will not be accurate, since determining the camera angle must be done at run time.
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