Attribute Gradient SOP (Patreon)

Computes the gradient of a scalar attribute using connectivity or proximity.

Gradient of a scalar value is an extremely useful concept, and even though we have this as volumegradient in Houdini in the form of a volume operation, it's still very beneficial to know how to compute this manually, particularly without using volumes.

PolyFrame SOP and Measure SOP also have methods to compute the gradient, but neither SOP can compute it for point clouds. 

I used this exact technique extensively in the cracks setup I created for the movie X-Men: Dark Phoenix, where this technique formed one of the key parts of the system. You can read more in depth details about it here. They explain a lot about the prep and the animation of the cracks:

https://vfxscience.com/2019/07/12/x-men-dark-phoenix/

https://www.dropbox.com/s/900qqbp1r458x8w/AttributeGradient_SOP_Animatrix.otl?dl=1