Shading attributes set the form and appearance of nParticle objects, including the object’s Particle Render Type, Color, and Opacity. nParticles are created with a default Particle Render Type, which is assigned to the nParticle object according to the nParticle style selected when the object was created. nParticle render types specify the form of the particles, as well as the method used to render the nParticle object.
Opacity, Color, and Incandescence attributes can be mapped on a per particle basis using the nParticle object’s internal shading ramps. These ramps allow you to map per particle shading attributes to nParticle properties such as Age, Particle ID, and Radius.
The default software render shaders for nParticles have connections from particleSampleInfo nodes, so that the per-particle Color, Opacity and Incandescence appear in the render. If you assign new shaders to the nParticle object, you must also connect the particleSamplerInfo node to the shaders.