Lesson 6 gave you material rules. Lesson 7 turns those rules into a faster production system: one trim sheet plus one compact atlas you can reuse across walls, edges, and props without creating a new texture set for every object.

Lesson Objective

By the end of this lesson you will have:

1. One trim sheet texture plan with at least five strips (metal edge, plaster edge, wood edge, bevel accent, damage strip)
2. One small atlas layout for shared props (for example signs, bolts, vents, decals)
3. A short padding and mipmap checklist so your trims do not bleed in engine

Step 1: Decide what belongs in trim vs atlas

Use this split to avoid confusion:

• Trim sheet = repeatable linear details for long surfaces (edges, borders, frame lines, panel seams)
• Atlas = packed unique islands for small props that do not need endless tiling

If a detail appears across many objects and can be mapped as a strip, put it in trim. If it is unique and tiny, put it in atlas.

Common mistake: Treating the trim sheet like a random sticker board. Keep it linear and predictable.

Step 2: Build a trim layout before painting detail

In Blender UV space:

1. Create horizontal strips with clear height ratios (for example hero trim taller than minor trims).
2. Reserve tiny spacer bands between strips for safety margins.
3. Keep one optional neutral strip for late-stage fixes.

Name each strip in your planning note so teammates can map quickly:

• TRIM_01_MetalEdge
• TRIM_02_PlasterEdge
• TRIM_03_WoodEdge
• TRIM_04_PanelBevel
• TRIM_05_DamageAccent

Step 3: Pack atlas islands with predictable grouping

For atlas content:

1. Group similar assets (mechanical, signage, organic accents).
2. Keep rotation consistent where directional grain matters.
3. Leave enough pixel padding around each island.

For stylized kits, a tidy atlas often beats larger noisy textures. You gain easier edits and fewer accidental style drifts.

Step 4: Padding and mipmap safety checks

Before export, run this checklist:

• [ ] Each island/strip has edge padding (bleed) to survive lower mip levels
• [ ] No critical detail sits on UV borders without bleed room
• [ ] Atlas islands are not packed so tightly that color bleed appears in viewport test

Quick test: preview at distance in Blender viewport and verify strip boundaries do not contaminate neighboring regions.

Step 5: Apply trims to modular kit pieces

Map your Lesson 3-4 assets:

1. Wall and floor borders -> trim strips
2. Door frames and beams -> trim strips
3. Small detail props -> atlas islands

This should reduce material variety while maintaining visual richness.

Pro tip: Keep one material instance for the trim sheet and one for atlas-driven props. Fewer materials usually means cleaner runtime behavior.

Mini Task

Create one hero corner module that uses:

• at least two trim strips
• at least one atlas island

Then render one close shot and one mid-distance shot. If both read clearly, your layout is working.

Troubleshooting

• Trim looks stretched -> UV shell height does not match intended strip proportion. Re-scale shells, not the texture.
• Bleeding on edges -> insufficient padding or aggressive compression. Increase bleed and retest at distance.
• Scene looks repetitive -> add subtle hue/value variation via material parameters, not by breaking trim consistency.

FAQ

Should every prop use the atlas?
No. Hero props can still use unique textures. Atlas is for repeated small assets and efficiency.

Can I use one texture for both trim and atlas?
You can, but keep clear zones and naming so UV mapping stays readable and maintainable.

Recap

• You split repeatable details (trim) from packed uniques (atlas)
• You built a safety-first layout with bleed and naming discipline
• You mapped real kit pieces and confirmed readability at multiple distances

Next Lesson Teaser

Continue to Lesson 8: Foliage and Set Dressing in Blender to add depth layers and focal hierarchy without cluttering silhouettes.

Related reading: Blender for Game Assets and the texturing chapter.