Region fill

Region fill (B) detects an enclosed area and fills it — like a paint bucket bounded by surrounding geometry. It works well on architectural floor plans: click inside a room and Vellum traces the walls to create a filled entity, including holes when inner boundaries (columns, courtyards) are present.

1. 1
   Activate

   Open the + menu and choose Region fill, or press B.

2. 2
   Set fill & gap (optional)

   With nothing selected, the Properties panel shows Fill (color and opacity) and Gap tolerance. On phone or tablet, use the modal pill: fill swatch plus the Gap button.

3. 3
   Click inside

   Click within a region bounded by lines. A ghost preview follows the cursor; click to commit a filled entity and return to Select.

4. 4
   Add to a fill (Shift)

   Hold Shift and click another region to add it to the fill it touches — the same polygon grows. Shift+click inside a hole (a column, a stair opening) to fill it in, or into the room next door to extend the fill across the shared wall. The bucket stays active so you can keep adding; each addition is one undo step. Escape exits the tool.

Adding to a fill (Shift)

Shift+click adds the region under the cursor to the bucket fill it touches, overlaps, or sits inside a hole of (the most recent one, if several qualify) — one polygon, one color, no seams. Use it to fill a hole the room fill left around a column or fixture, or to grow a room fill into an adjoining closet or hall. If the region touches no existing fill, Shift+click starts a new fill. Shift+clicking an area that is already filled does nothing. The bucket stays active after each Shift+click; with Keep drawing tool active enabled in Preferences it also stays active after a plain click.

Merge shapes (after placing)

A plain click never merges — each fill is its own polygon. To grow one fill as you go, use Shift+click (above). To combine fills that are already placed (or that don't touch), select them (or any closed polygons, areas, or rectangles) and right-click → Merge shapes. Vellum replaces the selection with a single compound fill that shares one color and opacity (from the primary selection). Undo restores the original separate entities.

Gap tolerance

Imported plans often have tiny gaps at wall corners where lines do not quite meet. Gap tolerance tells Vellum how large a gap it may bridge when deciding what counts as a closed room — similar to Illustrator’s Live Paint Paint stops at setting.

Gap sizes are measured in screen pixels, then converted to world units at your current zoom — so Medium feels the same whether you are zoomed in on one suite or viewing a whole floor. The panel shows both px and world values at the current zoom.

Fill color & opacity

While the bucket tool is active, Fill controls in the Properties panel set the color and opacity of the next fill you place — the same pre-place pattern as the Highlight tool. After committing, select the polygon to restyle it (move, scale, rotate, or change fill in Properties).

Holes & nested boundaries

• Click in the ring between an outer wall and an inner rectangle (e.g. a column footprint) to fill the outer area with a hole cut out.
• Click inside an inner boundary to fill only that cell.
• Dividing walls that meet the outer boundary split the plan into separate cells — click in each cell to fill it independently.

Architectural plans — tips

• Dashed and dash-dot lines (overhead outlines, beams, truss and center lines) and imported hatch don't split a room — the fill passes under them. They only bound a fill when nothing solid encloses the click.
• Every solid line counts. Fills stop at any drawn line, including dimension and extension lines that cross a room; zoom in to see which line stopped a fill.
• Use Medium gap first on PDF imports; switch to Large only if corners still fail.
• Separate wall lines (four lines forming a rectangle) still work — the fill is traced from the exact intersections of all nearby linework, keeping every vertex.
• Nearly closed polylines (last point near the first) can be bridged when the gap is within tolerance.
• If you see too complex to fill, zoom to a single room or hide decorative layers, then try again.