| name | texture-uv-material-workflow |
| description | Create and validate Blender UVs, atlases, PBR image materials, decals, and bake targets for Blender and OVRTX. Use when textures stretch, colors are wrong, alpha is black, baking fails, or a material must survive USD/MaterialX handoff. The OVRTX runtime/client is installed and not a required source checkout. |
| license | Apache-2.0 |
| metadata | {"author":"Max Bickley","version":"0.1","team":"omniverse","domain":"physical-ai","tags":["blender","omniverse","ovrtx","materials","workflow"]} |
Texture and UV material workflow
Keep geometry, UV layout, image interpretation, and renderer conversion as
separate checks. A successful node edit or Blender preview does not prove that
the OVRTX MaterialX/OpenPBR result is faithful.
When to Use
Use when textures stretch, colors are wrong, alpha is black, baking fails, or a material must survive USD/MaterialX handoff. The OVRTX runtime/client is installed and not a required source checkout.
Instructions
- Copy the source
.blend and textures into a caller-owned working/output
directory. Record image hashes, dimensions, intended color space, and mesh
identity. Use stable UV-layer and material names.
- Choose unwrap, projection, or atlas layout by surface type. For a reference
plane or logo, register the front-facing UVs to measured image bounds; for a
closed asset, inspect front, back, and side coverage separately.
- Use
sRGB for base color/emissive color images and Non-Color for roughness,
metallic, normal, bump, AO, and masks. Connect normal images through a
Normal Map/Bump node, not directly to color.
- For atlases, map each mesh region into its own declared rectangle. Do not
apply a whole atlas to every part. For alpha, connect image alpha and enable
the documented blend/clip mode; reject black backing planes.
- For baking, use the supported engine and an active image target with a valid
UV map. Preserve cage, margin, resolution, and color-space settings in the
report; save the bake as a derived artifact.
Read references/bpy-recipes.md before authoring or repairing UVs and image
materials. It contains Blender 5.1 patterns for context-free planar UVs,
context-prepared unwraps, reachable Principled materials, normal maps, alpha,
polygon material assignment, and bake targets. Run each pattern as its own
blender-python-execution transaction and verify its JSON postcondition.
Use blender-community-skill-bootstrap to install upstream
blender-uv-texturing and blender-materials when detailed optional recipes
are needed. Execute them through blender-python-execution so active-object,
mode, color-space, and output-path state are explicit and checked.
Validation loop
- Apply a checker or numbered UV test and inspect a camera render for stretching,
flips, seams, overlap, and atlas registration.
- Confirm each polygon has the intended material slot and active UV layer; check
evaluated geometry if modifiers change topology.
- Render a neutral Blender control, then use
ovrtx-materialx-openpbr with the
same camera/lighting to classify each used material as faithful, approximate,
unbound, or runtime-unavailable.
- Diagnose in order: runtime/readback → material identity/binding → texture
path/UV/color space → light/exposure/display transform → individual lobe.
Do not alter albedo to conceal a tone-map or lighting problem.
Run the read-only scripts/audit_material_uv.py through Blender Python after
authoring and before render/export. Require status: pass for the visible meshes
in scope. A pass requires at least one renderable mesh, valid reachable material
outputs and image files, role-appropriate image color spaces, assigned polygon
materials, required UV layers, finite UV coordinates, no non-UDIM coordinates
outside the unit tile, and no nonzero-area face collapsed to zero UV area.
Treat orphan image nodes and unused material slots as cleanup warnings; inspect
them even though they do not fail the audit. Declare UDIM use with a reachable
tiled image or the object boolean property uv_allow_udim.
For MCP, prepend MATERIAL_UV_AUDIT_REQUEST = {} and append the complete audit
script in the same execution call; require the printed JSON to pass. For a
saved caller-owned scene, use blender --background scene.blend --python scripts/audit_material_uv.py; a failing audit exits with status 2.
Handoff
Summarize the objects/materials changed, whether the audit passed, and any
remaining color-space, UV, or dependency issue. Include hashes, the complete
JSON audit, checker/bake previews, or a dependency inventory only when the
caller needs a reproducible handoff or review artifact. Keep source references
and image planes out of final USD/GLB unless requested.
