Dv vex function

Contexts: cop , displace , fog , light , photon , shadow , surface

Tags: math, shading

Takes the derivative of the given value with respect to V.

1. float Dv(float )

2. vector Dv(vector )

3. vector4 Dv(vector4 )

Takes the derivative of the given value with respect to V.

In shading contexts, this is the change in the variable over the area being shaded.

You can [specify optional parameters|] to control the computation.