An open-source 3D painting utility for Houdini that won gold in the 2021 SideFX Tech Art Challenge. HPaint allows you to digitally paint on any 3D geometry, as well as utilise 2D animation capabilities to bring 2D-3D hybrid workflows to life with complex Houdini proceduralism.
The HDA uses a Python viewer-state and viewport-based intersection analysis to allow colour picking, screen drawing (for annotations) and a variety of optimisations in caching and geometry handling that provide a smooth, efficient, customisable experience.
HPaint has also seen acclaim in the wider Houdini community, most notably in Tumblehead's Stylized Look Development in Solaris talk at Annecy HIVE 2023, and on the USD VFX YouTube channel.
You can download the HDA, or just check out the codebase on GitHub
PolyPaint, the predecessor to HPaint (an adapted version of the Stroke HDA viewer-state), inspired the hot-caching and 2D animation functionality of HPaint. However, because it relied so heavily on expensive Python functionality, a total rewrite was needed to fit the level of realtime interactivity that HPaint now provides. Check out the Code projects page for more info