Notes

Known Limitations

• OptiDraw is an editor-only tool — no runtime painting API is exposed. All painting must occur in the Unity Editor.
• Undo history is limited to the last 50 brush strokes per session. Redo is supported within the same session only.
• Meshes with more than 65,535 vertices require a 32-bit index buffer. OptiDraw auto-detects and handles both, but Unity versions before 2022.2 may need manual index format override.
• UDIM support is limited to 10 tiles (1001–1010) per mesh. Meshes with more tiles will paint correctly on the first 10; additional tiles are silently skipped.
• Tablet pressure sensitivity requires Unity's Input System package (not the legacy input manager). Ensure Input System is installed and active.

Compatibility Notes

• Unity 2022.3 LTS: Full support. Recommended for production.
• Unity 2023.x: Full support.
• Unity 6 (6000.0+): Full support. GPU Resident Drawer compatible.
• Unity 2021.x: Partial support — Animation Draw Mode unavailable (Job System limitation). Burst and Vertex Paint work.
• Built-in Render Pipeline: Supported. HDRP Mask Map packing preset is HDRP-specific but the packer tool works in all pipelines.

Deliberate Design Decisions

• No runtime API — keeps the package editor-only and zero-cost in builds
• ScriptableObject storage over Scene data — painting data survives scene reloads and is version-control friendly
• Per-stroke undo (not per-frame) — reduces undo stack memory; continuous stroke counts as one undoable action
• No automatic LOD painting — deliberate; LOD mesh topologies differ enough that manual LOD baking produces better results