SideFX Houdini VFX Simulation Geometry Cache ($HIP/geo)

Bottom Line: It is safe to delete .bgeo.sc simulation cache files for completed VFX shots. Houdini caches fluid, smoke, pyro, and destruction particle geometry to allow fast playback in the viewport.

Why Does Houdini Simulation Cache Exist?

SideFX Houdini is the industry-standard procedural 3D animation and visual effects (VFX) software. Simulating complex smoke, fire, water, or destruction requires calculating millions of particle coordinates per frame.

• Primary Purpose: Frame-by-frame storage of calculated particle, VDB grid, and geometry dynamics (.bgeo.sc, .vdb).
• Storage Impact: A single 100-frame pyro simulation can consume 10 GB to 100 GB+ of SSD space.
• Playback Speed: Without disk caches, Houdini would have to re-simulate physics dynamically on every frame.

What Happens If You Delete Houdini Sim Cache?

• System Safety: ✅ Safe to Delete. Your .hip project scene file is preserved.
• Re-Simulation: To view the simulation again, you simply press “Press Play” or “Save to Disk” on the File Cache node to re-simulate.
• Reclaimed Storage: Reclaims 10 GB to 100 GB+ of storage space.

How to Delete Houdini Simulation Cache

# Remove cached simulation geometry files
rm -rf $HIP/geo/*.bgeo.sc $HIP/geo/*.vdb

Frequently Asked Questions (FAQ)

Will deleting .bgeo.sc files ruin my final Karma/Mantra render?

If your render node relies on disk caches to render geometry, deleting .bgeo.sc files will cause render errors until you re-cache the simulation node.