render-studio

Upload a 3D file, pick a few studio knobs (or describe a style in words), and Blender EEVEE renders a studio product image. Standalone — point it at any mesh or STEP file, not just one source.

This is the rendering stage of a two-tool pipeline: a CAD tool builds the part (see the companion modeling app), and render-studio turns it into a product shot. They are independent; use either alone.

How it works

browser (upload + knob controls + style box + result image)
  | localhost
FastAPI backend
  |- ingest: STL/OBJ/PLY/glTF/GLB pass through; STEP/IGES -> freecad.cmd converts to STL
  |- brain (optional): claude -p maps a style phrase -> knob values
  |- scene:  a curated studio template + knobs -> a Blender bpy script
  |          (auto-frames the camera to the model, 3-point lighting, floor, material)
  |- render: blender --background --python <script>  (sandboxed) -> out.png (EEVEE)
browser shows the rendered image

The studio scene is a fixed, well-lit template; the knobs only adjust it, so renders are consistently presentable rather than depending on AI to light a scene.

Knobs

• material: matte / plastic / metal / clay
• color: any hex
• background: white / grey / dark / gradient
• angle: front / iso / top_front / back
• resolution: 1024 / 2048

The optional "style in words" box (e.g. "brushed aluminium, dark background") asks claude to fill the knobs for you.

Requirements

• Python 3.11+
• Blender on PATH (renders via blender --background; EEVEE)
• Optional: FreeCAD (freecadcmd/freecad.cmd) — only needed to render STEP/IGES
• Optional: the claude CLI — only for the "style in words" feature

Install

git clone <this-repo> render-studio && cd render-studio
python -m venv .venv && . .venv/bin/activate   # or: uv venv && . .venv/bin/activate
pip install -e ".[dev]"                          # or: uv pip install -e ".[dev]"

Run

python -m render_studio
# open http://127.0.0.1:8098, upload a 3D file, pick knobs, click render

Configuration

Env var	Default	Purpose
RENDER_STUDIO_BLENDER	blender	Force the Blender binary name/path
RENDER_STUDIO_FREECAD	auto-detect	Force the FreeCAD binary (STEP conversion)
RENDER_STUDIO_SCRATCH	~/render-studio-scratch	Where uploads render and the PNG lands

The default scratch is a non-hidden directory under $HOME on purpose: a snap Blender/FreeCAD has a private /tmp and its sandbox cannot read dotfiles, so neither /tmp nor a ~/.dotdir scratch would be visible to the renderer.

Safety

The render runs generated Blender Python, so it is sandboxed lightly for personal single-user use: a per-run scratch dir as the working dir, a timeout, a scrubbed environment (secrets are not passed to the Blender/FreeCAD subprocess), and a 50 MB upload cap. The optional claude -p brain runs with file/shell tools disabled and in a throwaway directory. For multi-user or untrusted use, tighten this with bubblewrap. Per-run scratch dirs accumulate under ~/render-studio-scratch; prune it periodically.

Tests

pytest            # unit tests run anywhere; the real Blender end-to-end
                  # acceptance test auto-skips when Blender is absent

License

MIT (c) 林亞澤