# HOUDINI — Knowledge MOC > [!abstract] About > Personal **Houdini** knowledge base — covers UI, SOP-level techniques, VEX & HScript / Python, TOPs, custom HDAs, environment workflows, and integrations. **Solaris** (LOPs / USD) and **Karma** (renderer) have their own MOCs and live under `SOLARIS/` and `KARMA/`. > [!note] State of the vault > Some notes are still in French / unfinished / outdated — being cleaned up progressively. Expect WIP content in less-used sections. ## 🧭 Reading Order for Newcomers 1. **UI basics** — [[UI/Houdini Hotkey|Hotkeys]], [[UI/Houdini HDA version|HDA versioning]]. 2. **SOP core** — [[SOP/Houdini Pick n Place|Pick n Place]] → [[SOP/Houdini Bound|Bound]] → [[SOP/Houdini Group by Range|Group by Range]] → [[SOP/HOUDINI Scatter|Scatter]]. 3. **VEX foundations** — [[VEX/HOUDINI VEX|HOUDINI VEX]] then the targeted VEX snippets. 4. **HScript / expressions** — [[HSCRIPT/Houdini Commonly used Expression|Commonly used Expressions]]. 5. **Solaris (LOPs / USD)** — [[SOLARIS/SOLARIS MOC|SOLARIS MOC]]. 6. **Karma** — [[KARMA/KARMA MOC|KARMA MOC]]. --- ## 💻 UI - [[UI/Houdini Hotkey|Houdini Hotkeys]] — useful keyboard shortcuts. - [[UI/Houdini HDA version|HDA versioning]] — major / minor version conventions. ## 🟦 SOP — Geometry - [[SOP/Houdini Pick n Place|Pick n Place]] — interactive object placement. - [[SOP/Houdini Bound|Bound]] — bounding box workflows. - [[SOP/Houdini Group by Range|Group by Range]] — selection ranges. - [[SOP/Houdini Curve from edge|Curve from Edge]] — extracting curves from geometry. - [[SOP/Houdini Scatter on curve|Scatter on Curve]] — point scattering on curves. - [[SOP/HOUDINI Scatter|HOUDINI Scatter]] — general scatter setup. - [[SOP/HOUDINI Proxy|HOUDINI Proxy]] — proxy geometry generation. - [[SOP/HOUDINI Alembic export fix|Alembic export fix]] — fix common ABC export issues. ## ⌨️ VEX - [[VEX/HOUDINI VEX|HOUDINI VEX]] — VEX fundamentals. - [[VEX/HOUDINI Guideline for AI generated VEX|Guideline for AI-generated VEX]] — patterns for prompting AI to write reliable VEX. - [[VEX/VEX Assign Material to Instances|VEX — Assign Material to Instances]]. - [[VEX/VEX Delete every point with normal not pointing at the center of the world|VEX — Delete points not facing world center]]. - [[VEX/VEX Delete last value in path|VEX — Delete last value in path]]. - [[VEX/VEX Make groups or Materials from Geometry Path|VEX — Groups / Materials from Geometry Path]]. - [[VEX/VEX Object to world center|VEX — Object to world center]]. - [[VEX/VEX Transfer Group to Attribute|VEX — Transfer Group to Attribute]]. ## 🔢 HScript / Expressions / Python - [[HSCRIPT/Houdini Commonly used Expression|Commonly used Expressions]] — large reference of HScript expressions. - [[HSCRIPT/HOUDINI Variables|HOUDINI Variables]] — common globals. - [[HSCRIPT/HOUDINI Search and replace|HScript Search and Replace]]. - [[HSCRIPT/Houdini Repath Texture|Repath Texture]] — batch retarget texture paths. ## 🧩 HDAs (Custom Tools) - [[HDA/HOUDINI HDA Render Stat display|Render Stat display HDA]] — Vincent's render-stat HDA setup. - See also LOP HDAs under [[SOLARIS/HDA/HOUDINI HDA SceneInspector|SOLARIS / HDA / SceneInspector]] and [[SOLARIS/HDA/HOUDINI HDA PythonPrinter|SOLARIS / HDA / PythonPrinter]]. ## 🟩 Environment Workflows - [[ENVIRONMENT/Houdini Environment Workflow|Houdini Environment Workflow]] — full env workflow. - [[ENVIRONMENT/Houdini Ivy|Houdini Ivy]] — procedural ivy. - [[ENVIRONMENT/Houdini Tree|Houdini Tree]] — procedural trees. - [[ENVIRONMENT/Houdini LOD Creation|LOD Creation]]. - [[ENVIRONMENT/Houdini Add Variant|Add Variant]] — variants for env assets. - [[ENVIRONMENT/LOOKDEV Houdini Terrain Projection Midg|Terrain Projection Lookdev]] — terrain texturing technique. - See also Scatter notes under [[SOP/HOUDINI Scatter|SOP / HOUDINI Scatter]] and [[SOP/Houdini Scatter on curve|SOP / Scatter on Curve]]. > [!info] Pipeline-level environment workflow > The OSMIUM pipeline's env workflow lives in [[../../ARTFX OSMIUM/PIPELINE/Notes/DETAILS/PIPELINE ENVIRONMENT|PIPELINE ENVIRONMENT]]. ## ⬛ TOPs - [[TOPNET/6.121 HOUDINI TOP network|TOP network basics]] — `6.121 HOUDINI TOP network`. - [[TOPNET/Houdini Deadline|Houdini → Deadline]] — submitting from Houdini. - See also Solaris-side TOP node: [[SOLARIS/WORKFLOW/SOLARIS TOP Render Fetch|SOLARIS TOP Render Fetch]]. ## 🔌 Integrations - [[INTEGRATIONS/7.1 Houdini to Unreal|Houdini → Unreal]] — exporting to Unreal Engine. - [[../../OUT OF PUBLISH/UNREAL ENGINE/Notes/7.2 Unreal to Houdini|Unreal → Houdini]] *(private legacy)*. ## 🟧 LOP — Solaris (USD) See the full [[SOLARIS/SOLARIS MOC|SOLARIS MOC]] for the complete index. ![[SOLARIS/SOLARIS MOC|SOLARIS MOC]] ## 🎥 Rendering — Karma See the full [[KARMA/KARMA MOC|KARMA MOC]] for the complete index. ## 🟪 FX - [[../../OUT OF PUBLISH/KNOWLEDGE OUT OF PUBLISH/BHGC/BHGC Houdini Clothing design|BHGC — Houdini Clothing design]] *(private legacy)*. --- ## 📚 Resources ### Free / Open Source - [Houdini — non-commercial to commercial upgrade](https://www.orbolt.com/upgrade-houdini-files). - [AwesomeHoudini — curated list of Houdini resources](https://github.com/wyhinton/AwesomeHoudini). ### Rodeo (Legacy / Private) - [[../../OUT OF PUBLISH/KNOWLEDGE OUT OF PUBLISH/STUDIO/RODEO/6.12 RDO HOUDINI|6.12 RDO HOUDINI]]. - [[../../OUT OF PUBLISH/KNOWLEDGE OUT OF PUBLISH/STUDIO/RODEO/6.17 RDO HOUDINI UV|6.17 RDO HOUDINI UV]]. - [[../../OUT OF PUBLISH/KNOWLEDGE OUT OF PUBLISH/STUDIO/RODEO/6.04 RDO HOUDINI ShotOveride SbS|6.04 RDO HOUDINI ShotOveride SbS]]. - [[../../OUT OF PUBLISH/KNOWLEDGE OUT OF PUBLISH/STUDIO/RODEO/6.03 RDO HOUDINI SetDressing SbS|6.03 RDO HOUDINI SetDressing SbS]]. - [[../../OUT OF PUBLISH/KNOWLEDGE OUT OF PUBLISH/STUDIO/RODEO/6.02 RDO HOUDINI Mod USD publish SbS|6.02 RDO HOUDINI Mod USD publish SbS]]. ### Discover - **Biome** — SideFX's biome tool. - **Copernicus** — Houdini 20's image-processing context. - [Houdini Berlin Sidewalk Generator — by Julian Bragagna](https://www.artstation.com/blogs/julianbragagna/31yo/houdini-berlin-sidewalk-generator-part-1). --- ## 🔗 Related MOCs - [[SOLARIS/SOLARIS MOC|SOLARIS MOC]] — LOPs / USD in Houdini. - [[KARMA/KARMA MOC|KARMA MOC]] — Houdini-native rendering. - [[../KNOWLEDGE MOC|KNOWLEDGE MOC]]. - [[../../PROTOCOL/USD/USD MOC|USD MOC]] — USD theory feeds Solaris. - [[../../ARTFX OSMIUM/PIPELINE/PIPELINE MOC|OSMIUM PIPELINE MOC]] — the pipeline that uses these tools.