UVs & unwrapping

Mon 2:00 · Brief Flattening for texture space

Unwrapping is the least glamorous hour in this course and the one that decides whether the next three weeks go well. Texturing a bad unwrap is like painting a wall that isn't flat — you can do it, and everyone will be able to tell.

Seams and unwrapping

A seam is a cut you authorise. The UV editor takes a closed 3D surface and lies it flat, and it can only do that by cutting somewhere — so the question is never whether to have seams but where you are willing to put them. Hide them where the eye doesn't travel: inside corners, under overhangs, along a natural break in the form. A seam on a flat visible face is a scar you will spend the texturing week trying to hide.

The test for a good unwrap is boring: no stretching, no overlapping where you didn't intend it, and islands laid out so a human could find their way around the texture.

Texel density

Texel density is pixels per unit of surface — how much texture resolution each piece actually receives. If one wall piece is at 512 px/m and the piece next to it is at 128, the second one looks blurry no matter how good the texture is, and no amount of painting will fix it. Consistency across a kit matters more than the number itself.

You measure it with a checker map, not by eye. Apply a checker, look at the model: even squares of even size mean even density. Squares that stretch mean the unwrap is distorted; squares that change size from piece to piece mean the density is inconsistent. This is the single most useful diagnostic in the whole course, and it takes ten seconds.

Trim sheets and layout

A trim sheet is one texture of reusable horizontal strips — edges, panels, pipes, trims — that many different pieces map onto. Instead of every object owning unique texture space, the whole kit shares one sheet. It is how modular environments are actually built in production: enormous coverage from a small memory budget, and a visual consistency you get for free.

Unique unwraps are for hero assets the camera will get close to. Trim sheets are for everything else. Knowing which you are making before you start unwrapping saves the entire afternoon.

Mon 2:45 · Guided lab Unwrap the kit

We unwrap one piece together, end to end, then you do the rest of your kit while I circulate.

1. Mark seams

   Edge select, choose your cuts, mark them. Say out loud why each seam is where it is — inside a corner, along a form break, hidden from the main view. If you can't justify it, move it.

2. Unwrap and inspect

   Unwrap, then open the UV editor beside the viewport. Look for islands that fold over themselves or stretch into ribbons. Fix by adding a seam, not by dragging vertices.

3. Check texel density with a checker map

   Apply the checker to the whole kit at once. Walk the camera around it. Every square should be square, and roughly the same size on every piece. Note where it isn't — that's your fix list.

4. Lay out the UVs efficiently

   Pack the islands. Straighten anything that wants to be straight — trims, panels, edges — because straight islands waste less space and are far easier to texture. Wasted UV space is wasted texture budget.

Wed 2:00 · Workbench Practice, unhurried

No new material. You work on your own file while I circulate — this is the hour where the technique from the guided lab stops being something you watched and becomes something you can do.

1. Unwrap the rest of your kit

   The lab covered one piece. The kit is three to five. This is the hour to finish them, with help two meters away.

2. If you fell behind, catch up here

   Say so and I will come to you — do not spend the hour quietly stuck. Unwrapping is the week where quiet stuck-ness costs the most later.

3. If you are ahead, go deeper

   Build a trim sheet layout for your kit and map two pieces onto it. Compare the texture space you save against unique unwraps.

4. Ask Gary, the AI TA, anything

   The tutor on the course site is open all term for questions about how and why. It explains; you build. No agents in the work until Week 9.

Wed 3:10 · Crit / share Checkers up

Screens up with the checker map applied — not the pretty view, the diagnostic view. We look at each other's kits for stretch and density mismatches, which are far easier to spot on someone else's work than your own. Bring the one seam you were least sure about.

Homework — due before Week 5

Resources

• Blender UV editing docs — seams, unwrapping methods, and the UV editor.
• Project 1 brief — the polycount and texel budget you are unwrapping to meet.