This page will go over the basics of Axiom and all the various setting you need to know about before creating your first simulation.
To create a new solver node you need to be in the SOP context in Houdini. Press tab to bring up the node menu and search for “Axiom Solver” in the dialogue. Then click anywhere to drop the solver down.
<aside> 💡 Axiom is not available in DOPs. It is implemented as a SOP node.
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By default, the solver will set the start frame to the first frame on your timeline. You can change this to whatever start frame you want.
If you have a fast-moving simulation you can add more substeps to make the motion resolve better. Doing this will slow down the solver.
Mode will let you set what fluid simulation algorithm you want to use. Traditional will use an algorithm that acts like classic old school fluid dynamics. Reflection will use the new reflection-advection algorithm to try and preserve energy that is usually lost with the traditional mode. Reflection single step is a faster version of the reflection mode but is not as accurate.
Division size will control the voxel size of the simulation grid. Smaller values will make the grid higher resolution.
The voxel parameter controls the starting number of voxels the simulation will use. This is not a hard limit and the solver will increase it if it needs more. You can set this value to be higher if you know you will be working with a large simulation but generally leaving it on the default is fine.
<aside> 💡 Making the voxels value higher will use more memory. By default with 32m voxels the solver will need 2.37GB of memory.
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API lets you choose what compute API you want the solver to use. OpenCL is the default and will work on most GPUs and CPUs. Metal is only available on macOS and will perform faster compared to OpenCL. Cuda is only available on Nvidia GPUs.
Device lets you pick what type of device you want to use. See the section on picking a device for more information.