Download free Houdini tools from SideFX’s Project Grot
Originally posted on 8 January 2025, and updated for the new Procedural Bridge tool.
SideFX has begun releasing custom Houdini tools developed for Project Grot, its in-house tech demo intended to showcase procedural world-building techniques for game development.
The first two tools are for generating procedural ruins and for generating procedural strands of flesh, both also available as .hda files that can be used in Unreal Engine.
Project Grot: showcasing art-directable techniques for building game worlds procedurally
Like 2022’s Project Titan, Project Grot is an in-house tech demo designed to test procedural workflows for creating 3D environment content for use in games.
The art-directed scene depicts an ancient, cave-like environment, partially filled with lava, and with walls and rocks covered with unnervingly organic-looking strands of ‘flesh’.
It was created by a team of five artists working under a two-month deadline, with the custom procedural tools created in Houdini then used to lay out the level inside Unreal Engine 5.
Procedural ruins, procedural flesh and procedural bridge tools now available to download
So far, two of those custom procedural tools have been released publicly, the first being one for generating procedural ruins.
Shown in the video above, it enables artists to turn rough blockout geometry into detailed high-poly meshes by painting areas of procedural damage on their surfaces using vertex colors.
The other, shown in the video at the top of the story, generates procedural webs of flesh.
It makes use of raycasting to shoot curves between surfaces in the scene that will later become flesh, then clusters curves based on proximity to give an organic structure to the results.
Updated 24 April 2025: SideFX has released a new Project Grot tool, for generating procedural ‘bridges’ – the horizontal rock structures bridging the caverns.
Unlike the first two tools, it is only available as a Houdini .hip file.
The Project Grot homepage also hosts videos without downloadable supporting files on creating the volcanic landscape and lava, and creating a rock-generation tool.
Price and system requirements
The Project Grot tools are available free as Houdini .hip files.
Some also include .hda files that can be imported and edited in DCC applications compatible with Houdini Engine, including Unreal Engine.
To use the .hda files inside Unreal Engine 5, you will need the Houdini Engine for Unreal plugin.
It is now included in the Houdini installer, and is free for use on commercial projects, but only works with commercial licenses of the software, not free Houdini Apprentice licenses.
You can find pricing and system requirements for Houdini in this story on Houdini 20.5.
Read more about Project Grot on the SideFX website
Download the free Project Grot procedural ruins tool for Houdini and Unreal Engine
Download the free Project Grot procedural flesh tool for Houdini and Unreal Engine
Download the free Project Grot procedural bridges tool for Houdini
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