SDF. What is it?

SDF: Scalar Distance Field 

A SDF is a function which calculates the distance to the surface of an object by using the space that object contains. You may notice that SDFs usually function with anything that has a volume or a VDB attribute. 

Here are some common SDF nodes: (As of Houdini 17.5)

SDF Geometry Nodes:

Paint SDF Volume

Volume SDF

VDB Topology to SDF

VDB smooth SDF

VDB reshape SDF

VDB re-normalize SDF

VDB Morph SDF

VDB Activate SDF

Convert VDB

SDF Dynamic Nodes:

SDF Representation

Gas SDF to Fog

Gas Particle to SDF

Gas reinitialize SDF

Gas geometry to SDF

What VFX Simulations Use SDF?

In Houdini some operations and simulations you might use SDFs for are:

  • Explosions

  • Fire

  • Smoke

  • Custom Volume Based Simulations

  • Fog simulations

  • Clouds

  • VDB simulations