Upload a PNG, JPG or WEBP, detect features, then review walls, portals and lights.
Upload a map, then set pixels per square. Use two clicks for a door or window; portals snap to nearby walls and create a gap. Click to draw a wall with several points, then press Enter. Escape cancels the unfinished wall.
Select an item to drag it or its endpoints. Delete removes it. Mouse wheel zooms; middle mouse or the Pan tool moves the view. Ctrl+Z undoes; Ctrl+Shift+Z redoes.
Detection is local image analysis, not a trained AI model. Choose Detection area and drag a rectangle to restrict it. Use whole map clears the rectangle. Detailed mode keeps more small features; Long wall runs reduces small clutter. These are size filters, not semantic recognition of buildings or containers. Dark or consistently coloured walls work best. Doors and windows are inferred from gaps; blue gaps are proposed as windows. Small bright cores near warm patches become light suggestions. Light reflections can still be mistaken for lamps. Review every suggestion before accepting it.
Object contour uses a local seeded colour selection with edge barriers, not an AI model. Limit the detection area to one object and click a representative patch. Increase colour tolerance to grow the patch. A contour follows visible pixels, including roofs or side faces; it does not recover a hidden footprint. Move points to the desired blocking line and exclude unwanted edges before adding suggestions. The convex option fills indentations and can cover empty space. Unfinished contours are not saved; add them as suggestions first.
UVTT contains accepted items only. Save your project to keep suggestions and edits. Import the UVTT in Roll20 using Create Page → Upload Background. Check the grid scale, portal types and light settings after import.
Use one map per floor. This tool does not modify your Roll20 account.