Spot

This group contains the Instance Info node. It allows access to all information regarding the current hit point for instances.

First let’s define what a “spot” is. A spot is just a spot - a fleck, a pinpoint. You can think of a spot as a single element area that is calculated or evaluated, on a surface and that it is arbitrary in size. Any given spot contains several types of data including color, normal angle, the direction that a ray is coming or going from relative to that spot, and so on. Remember Node Editor is a surface texture and shading editor so the word spot here pertains to the spots of an object’s surface. Spots are a useful primitive type for texture design, because, in general, the relations between features of the spot and features of the texture are straightforward.

Instance Info

This node gives control over instances - virtual polygons. I can be used to gain an ID Index for a particular instance, or get a Fixed Random index number for a non-specific instance.