Hi all
I was wondering if it is possible to create a voxel grid with variable voxel density. I am relatively new to houdini but i have made lots of numerical simulations before and i wanted to try that out in houdini. The goal is to simulate crack propagation but the density of voxels needed near the crack tip must be very high. This is not needed through the rest of the volume however. I have seen some simulations where the resolution of octree grids increases near boundaries. What i would need is a grid that does the same thing based on some particle attribute.

I would be able to code it in python or matlab but i'm not sure how to implement this in houdini. If anyone knows how one might approach this problem I would be very grateful

best wishes

Houdini supports VDB volumes via OpenVDB which is an hierarchical sparse volume data structure that supports narrow band SDFs. While it's not adaptive in the sense that for a given VDB primitive, you cannot have different voxel sizes, it's pretty efficient at doing SDFs with small voxel sizes. So I would just use the usual set of volume tools (eg. Volume Wrangle) in Houdini with VDB primitives.