Houdini expressions are functions available to help you calculate values in the parameters of the nodes. You may have seen $HIPNAME which returns the name of the current hip file. Or the centroid one that I use most often for procedural modeling, $CEX $CEY $CEZ, which returns the centroid vector component.

Building upon that collision detection, we can also use the SDF to deform the object upon the collision. Using the SDF value and some math, the grid can be deformed to create footprints stamped on by the Torus.

Step by step mathematical explanation of the Sine Wave function and how it’s used in defining motion. Increasing the frequency and increasing the amplitude and flipping the entire curve function.

This is an explanation of the math behind how the Height Ramp in the Height Field Mask by Feature node in Houdini is calculated.

This post explains a specific node, “set_density” and how the math works in calculating the density attribute. I’ll try to explain the math behind it and how the node works.