Texture atlas
Every mesh draws a rectangle of one texture page. Modeling > Texture Atlas… (or Edit atlas… at the top of the Texture palette) shows those rectangles as pieces on their pages, drawn with their own pixels, and lets you move and repack them. Nothing on the model changes: when you apply, the pixels move and every uv follows, so the model draws exactly as before.
The window
- Page tabs across the top, each with how many pieces it holds. Click one to see it.
- The page fills the middle, with a faint grid every 256 px. Click a piece to select it, drag to move it. Drag a piece onto another page's tab to move it there.
- Pieces on this page lists them by mesh name and size; selecting one highlights it.
- Page size: 1024 to 8192 px. Changing it lays the pieces out again.
- Auto layout packs every piece onto as few pages as fit, tallest first. Pieces bigger than a page are scaled down to fit when Scale pieces that don't fit is on; otherwise the layout says which piece is too big.
- New page and Delete page (an empty page only).
- Apply writes the new pages and uvs as one undo step. Until then nothing has changed.
When to use it
- After several imports and re-imports, when pages have gaps. Auto layout usually gets a model from six pages to three or four.
- Before export, to land on the page count and size a target wants.
- To keep related pieces together, or to move a heavy piece to its own page.
Notes
- Pieces keep a 4 px margin so filtering never samples a neighbour.
- Copies of a mesh that share one rectangle share one piece.
- The ArtPath colour page is not packed; it rides along unchanged.
- Pages no mesh uses afterwards are dropped, so an atlas never grows pages by itself. Texture memory decides how much of the atlas sits on the GPU at a time.