• Vellum is now a fully complete, unified multi-solver.

  • Vellum now has native support for simple fluid (XPBD) effects with basic viscosity and surface tension solve.

  • Native support for XPBD rigid bodies and plasticity.

  • Vellum grains and fluids are configured using the Vellum Configure Grains SOP. It now has parameters to set these attributes on points configured for a grain/fluid solve.

  • Vellum fluids can interact with Vellum cloth, balloons, grains, and softbodies. Interactions with Vellum hair are currently not supported.

  • The Vellum grain solve now uses GPU accelerated neighborhood search making it significantly faster.

  • New Packing Density attribute allows for over-packing and filling the input geometry completely. Be careful with values greater than 1 when simulating Vellum grains.

  • New Phase attribute lets you create multi-phase fluids from a single source.

  • Soft body optimizations for muscle, tissue & skin sims.

  • New Shape Match Rigidity option on the Vellum Post Process SOP that can be used to ensure all pieces of geometry constrained by a Shape Match constraint remain rigid by blending in the specified amount of rigid motion. This lets you create rigid objects (like plastic) that can be dented without popping back into position.

  • New Shape Match constraint type on the Vellum Constraints SOP, which can be used to add rigidity either on top of existing constraints such as cloth, or by itself to create mostly rigid objects that can interact with other Vellum geometry. This is useful for things like buttons on clothing.

  • New Constraint Browser for visualizing and managing, editing, and visualizing Vellum and RBD constraints. You can access this interface by choosing New Pane Type > Inspectors > Constraint Browser.

  • The Vellum Configure Grain SOP now uses disabled-blending and the gl_texture for its sprite options, resulting in much faster display with large grain counts.

  • The Vellum Solver SOP now has a dive target with multiple outputs. You can wire in POP forces to the FORCE output and add new Vellum geometry to the SOURCE output.

  • Vellum Rest Blend SOP and DOP now support Shape Match constraints.

  • Vellum Brush now has the ability to interact with grains and fluids realtime, which was previously limited to mesh type constraints. It also has a completely redesigned UI which is in-line with our new HUD UI design language. The Vellum Brush uses a fast, GPU-powered solver.


Shape match constraints require the latest driver for NVIDIA Ampere series cards. This is version 456.38 on Windows and version 450.80.02 on Linux.

If you don’t update your driver, you can alternatively set the following environment variable to disable this feature: HOUDINI_OCL_FEATURE_DISABLE=CL_DEVICE_DEVICE_ENQUEUE_SUPPORT. For more information, see environment variables.

What’s new in Houdini 19