Ray Origin[XYZ ]

Defines the starting point of the raytracing in global coordinates. This normally reflects the position of the active render camera.

Ray Direction[XYZ ]

This is the direction vector of the rendered ray. This vector defines the direction from the Ray Origin in which the ray is underway.

UVW[XYZ ]

The UVW coordinates at the point on a surface currently being rendered.

UVW Delta

The radius measured in UVW coordinates that is used for calculating the RIP/MIP/SAT samples.

Phong Normal

Defines the Normals at the object surface point currently being rendered.

Time

Defines the current animation time and can be used to control animated effects.