unity-assets

unity-assets — generation & import pipelines

API keys — hard boundary

Both pipelines use bring-your-own keys. The user enters keys themselves:

• Unity asset-gen: Window → MCP for Unity → Asset Gen tab (fal.ai / OpenRouter for images, Tripo / Meshy for models, Sketchfab for library import).
• Blender addon: Edit → Preferences → Add-ons → Blender MCP (Sketchfab / Hyper3D / Hunyuan3D), or env vars like BLENDERMCP_SKETCHFAB_API_KEY.

Never ask the user to paste a key into chat, never write keys into config files, never enter keys into fields for them. If a generation tool fails with an auth error, tell the user which tab needs a key and stop there. PolyHaven (textures/models/HDRIs) is free and needs no key.

Pipeline A — inside Unity (asset_gen group)

1. Activate once per session: manage_tools action: "activate", group asset_gen.
2. Tools: generate_image (sprites, textures, concept art), generate_model (text/image → 3D), generate_audio (SFX/music — stable since MCP for Unity v10.1.0; details in the unity-audio skill), import_model (Sketchfab search+import), import_model_file (local FBX/OBJ/glTF).
3. Generated assets land in the project — then fix import settings via manage_asset: sprites need PPU consistent with the project, point filtering for pixel art; models need scale/materials checked.
4. Generation is slow and costs the user money per call — batch thoughtfully, show the result (screenshot or image) before generating variants.

Pipeline B — Blender (blender MCP server)

Requires: Blender 3.0+ running, the blender-mcp addon installed and Connect to Claude clicked in the 3D View sidebar (N-panel → BlenderMCP tab). If blender tools fail, that connection is the first suspect — tell the user exactly those steps.

• Good for: real modeling work (parametric edits, modifiers, UV, materials), free PolyHaven assets, Hyper3D/Hunyuan3D generation, Sketchfab downloads, then export to Unity.
• The server exposes scene inspection, object/material creation, viewport screenshots, and execute_blender_code (arbitrary Python). Keep code snippets small and incremental; screenshot the viewport to verify each significant step visually.
• Export to Unity: FBX or glTF into the project's Assets/Art/Models/ (export via Blender code: bpy.ops.export_scene.fbx(filepath=..., use_selection=True)), then let Unity import and check settings via manage_asset. Unity applies a 90° X-rotation fix for Blender FBX automatically; verify scale (Blender meters vs Unity units) on first import.
• Blender-mcp and Unity-mcp don't talk to each other — the filesystem (the Assets folder) is the handoff point.
• Alternative on the radar: the official Blender Lab MCP server (blender.org/lab/mcp-server, Blender 5.1+) — better scene analysis/docs, but no PolyHaven/Sketchfab/Hyper3D asset integrations, which is why this plugin ships ahujasid/blender-mcp. Reconsider if the asset integrations land there.

Choosing

• 2D sprite/texture → Pipeline A generate_image.
• Stock/realistic props, HDRIs → Blender PolyHaven (free) or Sketchfab.
• Custom 3D that needs editing after generation → Blender (generate, refine, export).
• Quick one-shot 3D placeholder → Pipeline A generate_model.