The Billboard shader renders particles as 2D particles instead of 3D, similar to how the Particle (Sparks) shader did in previous versions of XSI. This shader is attached to the particle type by default (along with the Shape shader) when you create a particle cloud with the Particles simulator.
The Billboard shader provides a good surface for making the particles look as you want, such as by using a sprite with the Sprite shader attached, or using a shape with the Shape shader attached. You can control the particle’s form, how it’s textured, which way it faces (the camera, any ray, or using rotation), and if it rotates (rolls). The smoke shown on the left is created by rendering the rotation from particles.
For more details on each of the parameters, see Particle Billboard in the Shaders Reference.
If you have the Shape shader attached to the Billboard shader, its shape type overrides the shape set for the Billboard. For example, the smoke shown on the previous page uses the Turbulence shape type with falloff in the Shape shader, which is attached to the Billboard shader.
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