> [!abstract] Summary > Fix for **missing UVs after Alembic export → Maya import**. Root cause is **n-gons** (faces with more than 4 sides) that don't survive the round-trip cleanly. Solution: select faces with `@intrinsic:vertexcount > 4`, then run a **PolyFill / Clean** or convert to quads/tris before export. --- # Symptom UVs are missing when the Alembic file is opened in Maya. # Cause **N-gons** (faces with more than 4 sides) — they don't survive the Alembic round-trip cleanly, breaking UV islands at export. ![[DoNOTDelete/Attachments/6.129 HOUDINI Alembic export fix/image-20230816.png]] # Fix 1. **Group** all problematic faces: ``` @intrinsic:vertexcount > 4 ``` 2. **Clean / Divide / PolyFill** that group to convert n-gons into quads or tris. 3. (Optional) Run a **Clean SOP** with default settings to remove degenerate primitives. 4. Re-export to Alembic. # Prevention - Avoid n-gons during modeling (use a **Clean** node late in the SOP graph). - See [[../../../PROTOCOL/OPTIMISATION/Notes/Asset modeling Clean - Leo Hanrion|Asset Modeling Clean — Leo Hanrion]] for cleanup conventions. --- # 🔗 Related - [[../../../PROTOCOL/OPTIMISATION/Notes/Asset modeling Clean - Leo Hanrion|Asset Modeling Clean — Leo Hanrion]] — upstream non-manifold / n-gon checks. - [[../HOUDINI MOC|HOUDINI MOC]].