Texture Uv Material 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

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.