Side Effects posts a short look at using the new Granular Solid Tool in the latest version of Houdini. The Granular Solid tool uses the new position based dynamics solver in Houdini 14, making it possible to create super complex and detailed simulations for sand, snow, or any thick viscous material made up of macroscopic particles.

The new Position-Based Dynamics is multi-threaded thanks to its exclusive reliance on VEX-based operators. The granular solid tools can handle sand effects, artists can create solids, sheets or tethers to generate soft body, cloth and wire-like simulations.

Grains/Sand Solver Features:

  • Position-based dynamics (PBD)
  • Implemented 100% in VEX: fast, inherently multithreaded, eminently parallelizable
  • Built into DOPs as particle nodes, thus able to interact with all dynamic elements and forces
  • Unique friction model
  • Completely art-directable
  • Wet & dry sand support as well as support for solids, sheets and strands (the inexpensive and fast equivalent of FEM soft bodies, cloth and respectively wires; see the “granular” tools on the shelf and the new Point Deform SOP)
  • OpenCL acceleration 5-10x
  • Faster particle collision (5x) thanks to OpenVDB 3.0