How to use
- Copy the installation command and review the source package before installing it in your own agent environment.
- Check the source document for required tools, credentials and supported hosts.
- Describe your input and desired deliverable; review the output against the source material.
npx skills add https://github.com/el4cteo/blender-skills --skill blender-game-optimizationBefore you start
- Installation does not include a model subscription, API allowance or permission to access your files.
- Repository stars and installation counts describe activity, not an independent quality or security test.
Rendered from the source repository. Headings, examples, code, tables, links, and referenced images are preserved.
Game Optimization
The execution model is in blender-core. Always re-run blender-asset-qa after optimizing.
Procedure
- Measure:
scripts/mesh_stats.py -- --objects ... --budget mobile|roblox|web|vr|console|pc. It returns tris, estimated draw calls, materials, texture VRAM, bones, and the over-budget items. - Clean:
make_lods.py --cleanup(merge by distance 0.1 mm, dissolve degenerate, delete loose). Remove hidden faces: back-to-back faces and faces under other parts (qa_check→back_to_back, plus manual xray). - Reduce in this order (cheapest visual loss first): hidden/interior geometry → unnecessary edge loops on flat areas (Limited Dissolve 1–5°) → over-segmented cylinders → Decimate → bake detail to normals (
blender-texture-baking). - Materials: merge to 1–2 per asset (atlas / trim sheet / shared tiling material). Each material slot per mesh is roughly one draw call.
- LODs:
scripts/make_lods.py -- --objects SM_X --renamecreates_LOD1.._LOD3at 50/25/12.5%. Check every LOD silhouette withlook/review_shots. - Re-measure, then QA, then export (
blender-export-pipelines).
Budgets (guidance per asset, 2026)
| Platform | Hero char tris | Prop tris | Mats/asset | Max texture | Bones |
|---|---|---|---|---|---|
| Mobile | 5–15k | 0.3–3k | 1–2 | 1024 | ≤75 |
| Roblox | body ≤10,742 (head 4k, torso 1.75k, limb 1,248); accessory/clothing 4k | ≤20k per MeshPart | 1 (SurfaceAppearance) | 1024 (PBR), 4k max | R15 + optional |
| Web (three.js/Babylon) | 10–30k | 1–10k | 1–2 | 2048 | ≤100 |
| Standalone VR (Quest) | 10–40k | 1–10k | 1–3 | 2048 | ≤100 |
| Console / PC | 50–150k | 5–50k | 2–6 | 4096 | 150–300 |
| UE5 Nanite (static) | — | millions OK | few | 4096+ | n/a |
Whole-scene limits matter more than single assets: mobile ≈ 100–300k tris visible and < 100–200 draw calls; PC ≈ millions of tris and < 2–5k draw calls.
Decimate modes
| Mode | Use | Notes |
|---|---|---|
COLLAPSE (ratio) | organic, scans, LODs | use_symmetry, vertex group factor to protect faces/hands; triangulates |
UNSUBDIV (iterations) | meshes made by subdividing quads | restores the quad grid cleanly |
DISSOLVE (planar, angle) | hard-surface / CAD | delimit {"SEAM","SHARP","MATERIAL","UV"}; keeps the silhouette, makes n-gons → triangulate on export |
Protect UV seams and silhouette: decimate a copy, then compare. If UVs tear at LOD1, the ratio is too aggressive for that topology, so re-unwrap or use a manual LOD.
The hidden cost: vertex splits
GPU vertex count = unique (position, normal, UV, color) combinations. Every UV seam and hard edge duplicates vertices, so engine vertex counts are often 1.5–3× Blender's. Minimize seams where they aren't needed, keep hard edges = seams (so the split happens once), and don't add vertex colors or extra UV sets you don't use.
LOD rules
- Halve the tris per level. Switch at screen size ~0.5 / 0.25 / 0.125 (UE "Screen Size", Unity LOD Group %, Godot
lod_biasauto). - LODs keep the same materials (or fewer: merge them at LOD2+), same pivot, same bounds.
- Skeletal LODs: remove finger/face bones at LOD2+ (the engine bone-reduction tools handle this). Keep the skinning on the same skeleton.
- Far LOD / foliage: impostor/billboard. Unreal Nanite (static, opaque/masked) and Godot's auto mesh LOD can replace a hand-made chain.
- Roblox: no manual LODs.
RenderFidelity=Automaticdoes it. Keep each MeshPart ≤ 20k tris and use a simpleCollisionFidelity(Box/Hull) for non-walkable parts.
Draw calls and batching
- Merge static meshes that share a material and are always seen together (join objects). Don't merge across large areas, because that defeats frustum/occlusion culling.
- Instancing: repeated objects as linked duplicates (Alt+D, shared mesh) or collection instances. They export as instances (glTF
EXT_mesh_gpu_instancingwithexport_gpu_instances) or as one mesh + transforms in the engine. - Atlases/trim sheets: put many props on one texture set. Trim sheets let walls, panels and pipes share one 2k material.
- Texture memory (upper bound, uncompressed RGBA8 + mips): 1k = 5.3 MB, 2k = 21 MB, 4k = 85 MB. Engines compress (BC7/ASTC ≈ 4–8×). Pack grayscale maps into ORM channels to cut it 3×.
Collision
Keep collision separate and simple: boxes/convex hulls of ≤ 32–255 verts. UE UCX_<Mesh>_##, Godot -colonly/-convcolonly suffix, Unity MeshCollider on a simplified mesh, Roblox CollisionFidelity. Never use the render mesh as a physics mesh for anything that moves.
Rig and animation cost
Limit to 4 influences per vertex (vertex_group_limit_total(limit=4) + normalize). Remove non-deforming bones from the export (use_armature_deform_only). Bake constraints and drivers to keys. Shape keys cost memory per vertex, so drop unused ones and keep only deltas (glTF sparse accessors handle this).
Gotchas
- Decimate on meshes with unapplied modifiers:
make_lods.pyevaluates them first. Other paths need you to apply them. - Join (
Ctrl+J) merges materials and UV maps by name. Rename the UV maps identically first, or the UVs get lost. - The
Weldmodifier is the non-destructive merge by distance. Usemode="CONNECTED"to avoid welding separate parts. - Triangulate before measuring if the engine will. Quads already count as 2 tris in the stats.
