b3dUnlockMesh

Unlocks mesh and uploads changes to GPU (finalizes vertex/triangle modifications). Takes mesh (surface-based mesh entity). Returns nothing. Validates mesh exists, type is ENTITY_MESH, and is surface-based. Sets mesh->locked=false. If mesh->needsGPUUpload=true, calls RebuildGPUBuffersFromSurfaces(mesh) to create/update GPU vertex and index buffers. Silently returns on validation errors.

This function finalizes mesh editing and synchronizes CPU data to GPU. Critical step: all vertex/triangle modifications stay CPU-side until unlock - unlock triggers GPU buffer rebuild for rendering. RebuildGPUBuffersFromSurfaces: creates D3D12 vertex buffer (upload heap -> default heap copy), creates index buffer, updates buffer views, clears needsGPUUpload flag. Must call after: any mesh modification (b3dAddVertex/Triangle, b3dVertexCoords/Normal/TexCoords/Color, b3dDeleteVertex/Triangle, b3dUpdateNormals, b3dClearSurface). Unlock without modifications: if needsGPUUpload=false, simply sets locked=false (no GPU work). Use cases: (1) Finalize procedural mesh after building, (2) Apply vertex animation frame, (3) Complete mesh editing session, (4) Trigger rendering of modified geometry. Common pattern: b3dLockMesh(mesh), modify mesh, b3dUnlockMesh(mesh), render frame. GPU buffer creation: allocates GPU memory, copies vertex/index data via command queue, creates descriptor views, sets resource states. Performance: unlock can be expensive for large meshes (GPU upload bottleneck) - prefer batching modifications between single lock/unlock pair rather than lock/unlock per vertex. Multiple unlocks: calling unlock multiple times harmless but wasteful (rebuilds GPU buffers unnecessarily if needsGPUUpload still true from another operation). Frame-by-frame animation: lock once, modify vertices in loop, unlock once per frame for deforming mesh. Alternative: keep mesh locked for long editing sessions, unlock only when ready to render. Buffer size: GPU buffers sized to current vertex/index count - deleting vertices frees GPU memory on next unlock. Render timing: modified mesh renders with new geometry starting next frame after unlock. Error symptoms: if mesh modifications don't appear, check b3dUnlockMesh called, check needsGPUUpload being set properly. Upload heap: uses intermediate upload buffer for CPU->GPU transfer, then copies to default heap for GPU-optimal access.