| { |
| "id": "single-software-execution--cli--blender--task-23--ubuntu", |
| "snapshot": "Blender-4.2.3", |
| "instruction": "Cloth Drape Alembic `/home/user/Desktop/scene.blend` contains: - A `Sphere` UV-sphere mesh at the origin (radius 1.0, 32 segments x 16 rings, 482 verts) with a `Collision` modifier attached. - A `Cloth` subdivided plane (4x4 BU, 31 intervals per side -> 32x32 grid = 1024 verts after Blender's grid construction) at (0, 0, 2.5), with a `Cloth` modifier attached. Launch Blender by running `blender` from a terminal. For this workflow, use `/opt/blender/blender` for Blender command-line or background runs when working on `scene.blend`.\n\nThe Cloth modifier's point_cache covers frames 1..60 but the simulation has NOT been baked. - Scene `frame_start=1`, `frame_end=60`. Scene gravity = (0, 0, -9.81). Your task: run the cloth simulation so the plane drapes on top of the sphere, export an Alembic cache of the deforming Cloth mesh over frames 1..60, and save the scene so the frame-60 draped state is preserved in the Cloth mesh data. Concretely: 1. Use the initial cloth scene at `/home/user/Desktop/scene.blend`. 2. Bake the cloth simulation over frames 1..60. In headless Blender the reliable recipes are: cloth_mod = cloth.modifiers['Cloth'] pc = cloth_mod.point_cache pc.frame_start = 1; pc.frame_end = 60 bpy.ops.object.select_all(action='DESELECT') bpy.context.view_layer.objects.active = cloth cloth.select_set(True) with bpy.context.temp_override(scene=bpy.context.scene, point_cache=pc): bpy.ops.ptcache.bake_all(bake=True) Stepping each frame (`scene.frame_set(f); bpy.context.view_layer.update()`) is a safe fallback. 3. Export the Alembic cache to `/home/user/Desktop/drape.abc`. Use `bpy.ops.wm.alembic_export(filepath='/home/user/Desktop/drape.abc', start=1, end=60, selected=True, visible_objects_only=False)` with only `Cloth` selected so the cache covers the draping plane. The exporter defaults to the Ogawa container (magic bytes `Ogawa`). 4. Freeze the frame-60 draped geometry onto the Cloth mesh data so the draped state survives save/load. Cloth point caches are not embedded in saved .blend files, so you need to bake the result into plain mesh data. At frame 60: compute the evaluated mesh (`cloth.evaluated_get(bpy.context.evaluated_depsgraph_get())`), replace `cloth.data` with the evaluated geometry (e.g. via `bpy.data.meshes.new_from_object`), and remove the Cloth modifier. 5. Save the scene to `/home/user/Desktop/answer.blend`. Requirements =============== 1. `/home/user/Desktop/answer.blend` exists and opens. 2. Mesh object `Cloth` is present with at least 100 vertices. 3. `drape.abc` exists. 4. The first 5 bytes of `drape.abc` are `b'Ogawa'` (Alembic Ogawa magic signature). 5. `drape.abc` is at least 10 KB. 6. The Cloth vertex whose world XY is closest to the origin (the plane's center) has world Z in [0.95, 1.10] (resting on top of the radius-1 sphere within 5%-ish tolerance). 7. At least 98% of Cloth vertices have world-space distance from the origin >= 0.93 (no vertex has pierced the sphere surface significantly; accounts for collision thickness and numerical tolerance). 8. The Cloth bbox center Z has dropped at least 1.0 BU from the initial Z=2.5 (i.e., bbox-center Z <= 1.5), demonstrating that the cloth has actually deformed/draped rather than staying flat at its starting height.", |
| "source": "https://docs.blender.org/manual/en/4.1/; https://docs.blender.org/api/4.1/; https://developer.blender.org/docs/release_notes/4.1/; https://www.alembic.io/; https://www.loc.gov/preservation/digital/formats/fdd/fdd000507.shtml", |
| "config": [ |
| { |
| "type": "upload_file", |
| "parameters": { |
| "files": [ |
| { |
| "local_path": "task-23/init_file/scene.blend", |
| "path": "/home/user/Desktop/scene.blend" |
| } |
| ] |
| } |
| } |
| ], |
| "trajectory": "trajectories/", |
| "related_apps": [ |
| "blender" |
| ], |
| "artifact_paths": [ |
| "/home/user/Desktop/answer.blend", |
| "/home/user/Desktop/drape.abc" |
| ], |
| "evaluator": { |
| "postconfig": [ |
| { |
| "type": "upload_file", |
| "parameters": { |
| "files": [ |
| { |
| "local_path": "task-23/eval.py", |
| "path": "/home/user/Desktop/eval.py" |
| } |
| ] |
| } |
| } |
| ], |
| "func": "exact_match", |
| "result": { |
| "type": "vm_command_line", |
| "command": "python3 /home/user/Desktop/eval.py", |
| "shell": "true" |
| }, |
| "expected": { |
| "type": "rule", |
| "rules": { |
| "expected": "True\n" |
| } |
| } |
| }, |
| "proxy": false, |
| "fixed_ip": false, |
| "possibility_of_env_change": "low" |
| } |
|
|
