Render Window — hero
camera + framing set up by the AI contestant
3D Viewport — red-ball User Persp
LOADING 3D VIEW
$0.40Cost
111sDuration
8Tool calls
9Turns
Blender 5.1.0MCP 1.22026-07-15
Tokens: 86997/3550Vision: ✓Votes W-L-T: 0-0-0reasoning: effort mediumNO DONE
B-BENCH — TRANSCRIPT Anthropic / Claude Fable 5 / thinking:medium · r1 · 2026-07-15
RUN LOG — red-ball · Anthropic / Claude Fable 5 / thinking:medium · r1 · ok
SYSTEM PROMPTthe control — every model on this task got these instructions
PROMPTblender-bench v6HARNESSraw-v1
SHOW FULL PROMPT · 1104 chars
You are participating in Blender-Bench, a public benchmark where AI models complete the same Blender task. Your result will be compared head-to-head with another model. Anyone on the internet can vote, based only on the published visual outputs they can inspect: the interactive 3D scene and rendered presentation. Complete the request as well as you can. The benchmark does not prescribe a workflow or visual style; use whichever Blender techniques you consider appropriate. Make the important requirements evident in the published result, save a complete scene, and present the work clearly in every requested output. ## Harness Instructions You are operating Blender through the provided tools. The scene starts empty. Build what the user's prompt asks for in the current scene. Work step by step and verify your own work. Before you finish, set up a camera and lighting to frame a single, well-composed presentation image of your result — position and aim the camera, and add or adjust lights so the subject reads clearly. When you are finished, reply with the single word DONE and no tool calls.
--TASK red-ball: ## Task
Complete the following Blender task:
<task>
A red sphere of 1 meter diameter resting on a white ground plane — touching it
exactly, neither floating nor sunk. Smooth shading, a plain red material on the
ball, plain white on the floor.
The floor is the sphere, the color, and the contact. The ceiling is presentation:
a soft believable shadow under the ball, a hint of glossiness that catc…
47:09ai>I'll build this scene step by step: red sphere resting exactly on a white plane, then lighting and camera for presentation.
47:09>>execute_blender_code({"code":"\nimport bpy\n\n# Clear scene\nfor obj in list(bpy.data.objects):\n bpy.data.objects.remove(obj, do_unlink=True)\n\n# Ground plane\nbpy.ops.mesh.primitive_plane_add(size=40, location=(0,0,0))\nfloor = bpy.context.active_object\nfloor.name = \"Floor\"\nmat_f = bpy.data.materials.new(\"WhiteFloor\")\nmat_f.use_nodes = True\nbsdf = mat_f.node_tree.nodes[\"Principled BSDF\"]\nbsdf.inputs[\…)
47:09<<Code executed successfully: <Vector (0.0000, 0.0000, 0.5000)> <Vector (1.0000, 1.0000, 1.0000)>
47:21>>execute_blender_code({"code":"\nimport bpy, math\n\nscene = bpy.context.scene\n\n# Key light: large area light for soft shadow\nbpy.ops.object.light_add(type='AREA', location=(2.5, -2.0, 3.5))\nkey = bpy.context.active_object\nkey.name = \"KeyLight\"\nkey.data.energy = 400\nkey.data.size = 3.0\nkey.rotation_euler = (math.radians(40), 0, math.radians(50))\n\n# Fill light, dimmer\nbpy.ops.object.light_add(type='AREA', l…)
47:21<<Code executed successfully: done
47:28>>execute_blender_code({"code":"\nimport bpy\n# Set viewport to camera view and rendered shading for screenshot\nfor area in bpy.context.screen.areas:\n if area.type == 'VIEW_3D':\n for space in area.spaces:\n if space.type == 'VIEW_3D':\n space.region_3d.view_perspective = 'CAMERA'\n space.shading.type = 'RENDERED'\nprint(\"ok\")\n"})
47:28<<Code executed successfully: ok
47:33>>get_viewport_screenshot({"max_size":800,"user_prompt":"Red 1m sphere on white plane, glossy, soft shadow, clean framing"})
47:36<<
47:36imgimage delivered — get_viewport_screenshot
47:48ai>The scene looks good. Let me refine it slightly — a richer red, a bit more breathing room in the framing, and slightly stronger shadow definition:
47:48>>execute_blender_code({"code":"\nimport bpy, mathutils\n\n# Richer red\nb = bpy.data.materials[\"RedGloss\"].node_tree.nodes[\"Principled BSDF\"]\nb.inputs[\"Base Color\"].default_value = (0.65, 0.01, 0.015, 1)\nb.inputs[\"Roughness\"].default_value = 0.22\n\n# Pull camera back a touch for cleaner framing\ncam = bpy.data.objects[\"Camera\"]\ncam.location = (2.9, -2.9, 1.35)\ntarget = mathutils.Vector((0, 0, 0.42))\nd =…)
47:48<<Code executed successfully: ok
47:56>>get_viewport_screenshot({"max_size":800,"user_prompt":"Red 1m sphere on white plane, glossy, soft shadow, clean framing"})
47:58<<
47:58imgimage delivered — get_viewport_screenshot
48:13ai>The framing is good but the shadow under the ball could read more clearly. Let me strengthen the shadow definition and do a proper render check:
48:13>>execute_blender_code({"code":"\nimport bpy, math\n\n# Make key light a bit smaller & closer for a defined but still soft shadow\nkey = bpy.data.objects[\"KeyLight\"]\nkey.data.size = 2.0\nkey.location = (2.2, -1.8, 3.0)\nkey.data.energy = 380\n\n# Track lights toward sphere for correct aim\nimport mathutils\ntgt = mathutils.Vector((0,0,0.5))\nfor name in [\"KeyLight\",\"FillLight\",\"RimLight\"]:\n o = bpy.data.obj…)
48:13<<Error executing code: Communication error with Blender: Code execution error: Error: Cannot open file <repo>\apps\console\tmp\red_sphere.blend@ for writing: No such file or directory
48:23>>execute_blender_code({"code":"\nimport bpy, os, mathutils\n\n# lights were adjusted before save failed; re-apply to be safe\nkey = bpy.data.objects[\"KeyLight\"]\nkey.data.size = 2.0\nkey.location = (2.2, -1.8, 3.0)\nkey.data.energy = 380\ntgt = mathutils.Vector((0,0,0.5))\nfor name in [\"KeyLight\",\"FillLight\",\"RimLight\"]:\n o = bpy.data.objects[name]\n d = tgt - o.location\n o.rotation_euler = d.to_trac…)
48:23<<Code executed successfully: Info: Saved as "red_sphere.blend"
saved: <home>\red_sphere.blend
48:30--status: budget_exhausted
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