There are two ways to source with Axiom, VDBs and primitive shapes that come with the Axiom toolset called Source Shapes.

Activation Fields

Axiom expects a density field in order to know where to activate new regions of the sim. If you do not supply a density field it will fail to create any voxels in the simulation grid. You can however set temperature and fuel to be activation fields in the solver’s sparse settings.

OpenVDB

You can connect VDBs directly into the first input of the solver. You can make these sources any way you want. It can be sourced using OpenVDB or on the GPU using NanoVDB which is on by default.

Naming

Make sure to properly name all of your volumes as other names will not be compatible. It is case-sensitive.

• density
• temperature
• fuel
• vel (VDB vector type)
• pressure (divergence)
• color (VDB vector type)
• sink
• pump
• collision (Fog volume or SDF)
• collisionTemperature