BlenderMCP

Instructions

Implementation Reference

• src/blender_mcp/server.py:711-745 (handler)

  The core handler function for the generate_hyper3d_model_via_text tool. It is decorated with @mcp.tool() which registers it in the MCP server. The function processes the text prompt and optional bbox_condition, sends a 'create_rodin_job' command to the Blender connection, and returns the task details or error.
  @mcp.tool() def generate_hyper3d_model_via_text( ctx: Context, text_prompt: str, bbox_condition: list[float]=None ) -> str: """ Generate 3D asset using Hyper3D by giving description of the desired asset, and import the asset into Blender. The 3D asset has built-in materials. The generated model has a normalized size, so re-scaling after generation can be useful. Parameters: - text_prompt: A short description of the desired model in **English**. - bbox_condition: Optional. If given, it has to be a list of floats of length 3. Controls the ratio between [Length, Width, Height] of the model. Returns a message indicating success or failure. """ try: blender = get_blender_connection() result = blender.send_command("create_rodin_job", { "text_prompt": text_prompt, "images": None, "bbox_condition": _process_bbox(bbox_condition), }) succeed = result.get("submit_time", False) if succeed: return json.dumps({ "task_uuid": result["uuid"], "subscription_key": result["jobs"]["subscription_key"], }) else: return json.dumps(result) except Exception as e: logger.error(f"Error generating Hyper3D task: {str(e)}") return f"Error generating Hyper3D task: {str(e)}"
• src/blender_mcp/server.py:702-709 (helper)

  Helper function used by generate_hyper3d_model_via_text to process and normalize the bbox_condition parameter into integers between 0 and 100.
  def _process_bbox(original_bbox: list[float] | list[int] | None) -> list[int] | None: if original_bbox is None: return None if all(isinstance(i, int) for i in original_bbox): return original_bbox if any(i<=0 for i in original_bbox): raise ValueError("Incorrect number range: bbox must be bigger than zero!") return [int(float(i) / max(original_bbox) * 100) for i in original_bbox] if original_bbox else None
• src/blender_mcp/server.py:880-943 (helper)

  MCP prompt tool that provides strategy for asset creation, including instructions on when and how to use generate_hyper3d_model_via_text.
  def asset_creation_strategy() -> str: """Defines the preferred strategy for creating assets in Blender""" return """When creating 3D content in Blender, always start by checking if integrations are available: 0. Before anything, always check the scene from get_scene_info() 1. First use the following tools to verify if the following integrations are enabled: 1. PolyHaven Use get_polyhaven_status() to verify its status If PolyHaven is enabled: - For objects/models: Use download_polyhaven_asset() with asset_type="models" - For materials/textures: Use download_polyhaven_asset() with asset_type="textures" - For environment lighting: Use download_polyhaven_asset() with asset_type="hdris" 2. Sketchfab Sketchfab is good at Realistic models, and has a wider variety of models than PolyHaven. Use get_sketchfab_status() to verify its status If Sketchfab is enabled: - For objects/models: First search using search_sketchfab_models() with your query - Then download specific models using download_sketchfab_model() with the UID - Note that only downloadable models can be accessed, and API key must be properly configured - Sketchfab has a wider variety of models than PolyHaven, especially for specific subjects 3. Hyper3D(Rodin) Hyper3D Rodin is good at generating 3D models for single item. So don't try to: 1. Generate the whole scene with one shot 2. Generate ground using Hyper3D 3. Generate parts of the items separately and put them together afterwards Use get_hyper3d_status() to verify its status If Hyper3D is enabled: - For objects/models, do the following steps: 1. Create the model generation task - Use generate_hyper3d_model_via_images() if image(s) is/are given - Use generate_hyper3d_model_via_text() if generating 3D asset using text prompt If key type is free_trial and insufficient balance error returned, tell the user that the free trial key can only generated limited models everyday, they can choose to: - Wait for another day and try again - Go to hyper3d.ai to find out how to get their own API key - Go to fal.ai to get their own private API key 2. Poll the status - Use poll_rodin_job_status() to check if the generation task has completed or failed 3. Import the asset - Use import_generated_asset() to import the generated GLB model the asset 4. After importing the asset, ALWAYS check the world_bounding_box of the imported mesh, and adjust the mesh's location and size Adjust the imported mesh's location, scale, rotation, so that the mesh is on the right spot. You can reuse assets previous generated by running python code to duplicate the object, without creating another generation task. 3. Always check the world_bounding_box for each item so that: - Ensure that all objects that should not be clipping are not clipping. - Items have right spatial relationship. 4. Recommended asset source priority: - For specific existing objects: First try Sketchfab, then PolyHaven - For generic objects/furniture: First try PolyHaven, then Sketchfab - For custom or unique items not available in libraries: Use Hyper3D Rodin - For environment lighting: Use PolyHaven HDRIs - For materials/textures: Use PolyHaven textures Only fall back to scripting when: - PolyHaven, Sketchfab, and Hyper3D are all disabled - A simple primitive is explicitly requested - No suitable asset exists in any of the libraries - Hyper3D Rodin failed to generate the desired asset - The task specifically requires a basic material/color """