uv-workflow

UV Workflow

Efficient UV layouts with consistent texel density. Seams at hidden edges. Engine-ready.

When to Use

• After topology locked, before texturing
• Modular kit UV atlas planning
• Lightmap UV channel setup
• UDIM workflows for hero assets

Workflow

UV Planning → Seam Marking → Unwrap → Texel Density Check
    → Pack → Mirror/Overlap Decision → Lightmap UV (if needed) → Validation

Seam Placement Rules

Place seams at:

• Back of head, spine centerline
• Inner arms, inner legs
• Bottom of chin, underside of objects
• Panel edges on hard surface (construction seams)
• Hidden areas under clothing/overlaps

Never place seams on:

• Face (front)
• Primary gameplay-visible surfaces
• Deforming joint centers (relocate to nearby hidden area)

Texel Density

Formula: Texel Density = Texture Resolution / UV Island Size in UV space

Target consistency across visible surfaces:

Asset Tier	Target TD (px/m)
Hero	512–1024 px/m
Standard	256–512 px/m
Background	128–256 px/m

Use same density for modular kit pieces sharing atlas.

Unwrap Methods

Method	Use When
Smart UV Project	Quick blockout UVs only
Follow Active Quads	Strip UVs (roads, limbs)
Cube Project	Boxy hard surface
Lightmap Pack	Lightmap channel
Manual seam + Unwrap	Production default

UV Packing

• Margin: 0.002–0.01 UV units (engine dependent)
• Rotate islands for maximum packing efficiency
• Group islands by material ID
• Keep related islands near each other in UV space
• Use UVPackmaster or native pack for production

Mirrored UVs

• Mirror UVs for symmetrical characters (save texture space)
• Offset mirrored islands slightly if engine requires unique bakes
• Mark mirrored halves in object naming: _L / _R meshes if separate

UDIM Workflow

For hero assets exceeding single 4K texture:

• Tile 1001: head
• Tile 1002: torso
• Tile 1003: limbs
• Document tile assignment in production brief

Lightmap UVs

Second UV channel requirements:

• No overlapping islands
• Consistent texel density less critical
• Larger margin (0.02+) for light bleed prevention
• Pack separately from texture UVs

Modular UV Atlas

1. Plan shared atlas resolution (2048/4096)
2. Assign UV islands per module to atlas regions
3. Trim sheet regions for repeating detail
4. Vertex color variation for module differentiation
5. Document atlas layout for texture artist

MCP Integration

1. Mark seams via MCP if supported
2. Execute unwrap via MCP
3. Query UV island count and pack efficiency
4. Assign UV channels via MCP
5. Validate no overlapping UVs (except intentional mirror)

Validation Checklist

• No unintended overlapping UVs
• Consistent texel density on visible surfaces
• Seams hidden at gameplay angles
• UV islands within 0–1 (or UDIM tiles assigned)
• Lightmap channel separate if required
• Pack efficiency > 75%

Constraints

MUST DO

• Plan UVs before final modeling (topology informed by UV needs)
• Maintain texel density consistency
• Hide seams at logical construction edges
• Create lightmap UVs for baked lighting pipelines
• Document atlas layout for modular kits

MUST NOT DO

• Write code or snippets for Blender versions before 5.2, or add version fallbacks: this plugin targets 5.2+, and legacy branches teach users APIs that no longer exist
• Smart UV Project as final production UVs
• Overlapping UVs on unique surface detail (unless mirrored)
• Inconsistent texel density on same asset tier
• Seams across faces or primary visible surfaces
• Skip packing margins

Scripts

Tested on Blender 5.2 LTS via the official Blender MCP. Run with execute_blender_code (or headless, see the blender-mcp-workflow skill); read the script header for every argument. When the user will paste code into Blender themselves, give them the short runpy call with the absolute path of this installed script and their ARGS. Don't inline or rewrite the script: the tested file is the point.

Script	What it does
scripts/uv_unwrap_check.py	Unwrap (optional) and measure UVs: texel density, UV-space usage and out-of-range loops, per object. Unwrapping runs Smart UV Project with an island margin sized for the target texture resolution. lightmap: True adds a non-overlapping UVMap_Lightmap second channel (Lightmap Pack) and keeps the first channel as the render UV.

import runpy
result = runpy.run_path("<skill_dir>/scripts/uv_unwrap_check.py", init_globals={"ARGS": {...}})["result"]

ARGS: objects, unwrap, angle_deg, texture_px, target_px_per_m, lightmap

Reference Guide

Topic	Reference	Load When
Texel density calc	references/texel-density.md	Hero assets
Trim sheets	references/trim-sheets.md	Modular kits