# \[Open Source\] Crucible: Lazy HDA evaluation as a native Hydra Scene Index

**URL:** <https://forum.aousd.org/t/open-source-crucible-lazy-hda-evaluation-as-a-native-hydra-scene-index/2932>\
**Category:** Hydra\
**Created:** [May 30, 2026, 11:21am UTC](https://forum.aousd.org/t/open-source-crucible-lazy-hda-evaluation-as-a-native-hydra-scene-index/2932 "2026-05-30T11:21:50Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![plattipus](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/plattipus/32/1137_2.png) [@plattipus](https://forum.aousd.org/u/plattipus)\
**Post date:** [May 30, 2026, 11:21am UTC](https://forum.aousd.org/t/open-source-crucible-lazy-hda-evaluation-as-a-native-hydra-scene-index/2932/1 "2026-05-30T11:21:50Z")

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We just open-sourced Crucible.  
Cook Houdini HDAs lazily at Karma render time. Just a single USD prim pointing at your HDA. Karma pulls, Crucible cooks, mesh appears.  
MIT licensed. Built for production.

![testProcedural](https://us1.discourse-cdn.com/flex016/uploads/aousd/original/2X/9/9c5c1cf32bed78d70a64a62518d30abebd57a6bc.gif)

MIT licensed.

> **[Crucible — Cook Houdini HDAs at Karma Render Time as a Native Hydra Scene...](https://www.plattipus.com/research/crucible)**
>
> An open-source Hydra scene index plugin that cooks Houdini HDAs lazily at Karma render time. Author a CrucibleProcedural prim in USD and the referenced HDA is evaluated on Houdini's main thread, its output mesh injected into the Hydra scene — with no...

> **[GitHub - plattipus/crucible: Houdini HDA procedurals cooked automatically at...](https://github.com/plattipus/crucible)**
>
> Houdini HDA procedurals cooked automatically at Karma render time via a Hydra scene index plugin