The complete 3ds Max trim sheet workflow

The idea

What hotspotting is

A trim sheet is an atlas of rectangles (trims) you "snap" UV islands onto. Instead of fitting every island by hand, you select a batch of islands — and HotspotUV lays them out across the matching trims.

Video series

Trim Sheets in 3ds Max: the full series

Six short episodes, about 25 minutes total: model the sheet from one plane, bake and texture it in Substance Painter, let HotspotUV build the trim sheet from an ID map, then UV entire props in one click. Everything on this page, shown live.

1. Model the Sheet (primitives only, no sculpting)
   Start from a single plane in the Top view, cut it into bands with Connect, then extrude panel grooves and bevels. No sculpting and no high-poly detour: the sheet is built from primitives, so every trim stays a clean rectangle and the UV work later stays predictable.
2. Bake and Texture in Substance Painter (the ID map trick)
   Export the low poly, bake the mesh maps with a distance-based cage, then texture with layered smart materials. The trick is the second export: switch the template to Mesh Maps and pull the ID map out as its own file. That ID map is what builds your trim sheet in the next episode.
3. Your ID Map Builds the Trim Sheet FOR You
   Trims From Texture reads the flat colours of the ID map and detects every trim block on its own: colour tolerance, minimum block size, background ignored. Nine trims lifted straight out of one texture, with no rectangles drawn by hand and no drift between the sheet and the pixels.
4. UV Map Any Prop in ONE Click
   Add Unwrap_UVW, select the polygons, press Hotspot. Every island is matched to the closest trim by aspect ratio first and area second, straightened with a minimum-area bounding rectangle, then scaled so texel density matches across the whole selection. One undo step covers the entire run.
5. Thousands of Faces, ZERO Unwrapping: Quick UV + Hotspot
   Quick UV takes an unmapped blockout, breaks every hard edge into its own island and hands the result straight to the hotspot pass. Large modular geometry gets trim sheet UVs without a single seam placed by hand, which is where the time actually goes on environment work.
6. Quick UV + Hotspot: One Click Per Prop
   The same chain applied prop by prop across a modular kit, with matching priorities and texel density held identical between objects so nothing shifts scale from one piece to the next.

Trim sheets in 3ds Max have always been a manual job: line the island up with the trim, rotate it, scale it, check the density, repeat a few hundred times. The workflow above removes the repetition and leaves the decisions. Everything shown runs on the standard Unwrap_UVW modifier, so the result is a normal 3ds Max scene that any pipeline can open, and it works the same way in 3ds Max 2022 through 2027.

Setup · before you start

Build the trim sheet first

Hotspot needs a sheet of zones. The most reliable route: generate zones from existing UV islands — the trims then match the texture pixel-perfectly. A proven recipe (do it once, then just load the file):

Alternatives — when you don't want to cut geometry:

Workflow · 5 steps

From selection to a finished atlas

This is the real sequence — order matters.

Interface · full function reference

Anatomy of the window

Twelve areas = the complete reference. Click a number on the screenshot or an item in the legend — every area describes all of its controls. Use ‹ › to walk through the whole window.

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Screenshot from 3ds Max 2024, HotspotUV v2.4 · MK_EDDM props sheet (4096², 36 trims)

Interactive · the matching engine

Why did the island land right there?

A simulator of the engine inside a faithful replica of the tool's UI. Change the island's shape and the Matching settings — trim selection happens live, with the same logic as in Max: nearest aspect first, then nearest area. Read the result like the MAXScript Listener.

Mapping · modes

One island, three strategies

The Mode option decides how an island sits in a trim.

Seamless V works like Seamless U with the axes swapped (width fitted, vertical overflow). From trim settings reads each trim's own Fit axis — one pass mixes all three strategies on a single sheet.

Good to know

Concepts & mechanics