Ambient Occlusion¶

Surface → Ambient Occlusion

The soft dark line where two surfaces meet. Select the corner edges, press Create, and a strip is built along them carrying an AO gradient that fades from the corner out onto each wall.

It is one strip with a wing on each wall: at a true architectural corner the edge is shared by two faces, so the strip wraps onto both. An edge with only one adjacent face — a door frame, an open boundary — gets a single wing.

Making one¶

Select the object, enter Edit Mode, switch to edge select, and select the corner edges.
Back in the tool panel, leave Build From on Selection.
Press Create Ambient Occlusion.

Everything else is tuned afterwards, on the strip itself.

Build From¶

Selection — the strip runs along the edges you selected.

Ground Level — the strip runs along the contour where the mesh crosses a world height, with no Edit Mode and no selection at all. This is the answer for an object sunk into the floor, where the line you want is not an edge in the mesh: a wall that continues below the floor has no edge at floor level to select.

Ground Level is live on the finished strip too, so the height is a slider you can drag and watch. It is also the simplest way to lift a strip vertically, since it survives every rebuild by construction.

Nothing crosses that height

An object standing on the height rather than sunk through it is coplanar with it, and coplanar surfaces never cross. The tool lifts the plane by a 2 mm contact tolerance, takes the footprint, and drops the result back down by the same amount — so a resting object gives its exact footprint. If it still finds nothing, the panel says which of the three cases it is: the object is entirely below the height, entirely above it, or flat at it.

Selected Strip¶

Every row here rebuilds the strip as you drag it.

Shape¶

Setting	Does
Width	how far the AO reaches out onto each wall. This is the shelf the gradient fades across — 0.25 m by default, much wider than the other strip tools
Surface Offset	lift off the wall, so the decal does not z-fight. Capped at 0.05 m
Flip Direction	which side of the edge the strip is built on
Ground Level	only on a Ground Level strip: the height the contour is cut at

Fade¶

Across the shelf first — Alpha Center at the corner, Alpha Outer where it meets the wall, and Invert Fade to swap them.

Along the run second — Alpha Bottom and Alpha Top, so a corner that runs floor to ceiling does not have to arrive at either at full strength. Both at 1.0 is a no-op, not a flattening.

Bottom and top mean the bottom and top of the building, not of the object's axes: a wall whose object happens to be rotated still fades toward the actual floor. A run with no height — a wall-to-floor edge, all at one level — has nothing to fade between and is left alone rather than having its shelf faded.

The fade is linear, and that is a geometry limit

A run built from one selected edge has two vertices along its length, and two vertices cannot describe a curve. Subdivide the source edge for a tighter falloff — the same as everywhere else in these tools.

Position and Bevel¶

Shared with the other strip tools — see the tab.

What it builds¶

a strip mesh with a wing per adjacent wall, mitred where wings from different edges meet on the same wall
UVMap 0 fitted to the 0–1 square, upright, and Color 1 carrying the fade
a seto_fakeao material on decal.sps, reused per texture unless you ask for a new one
filed into the fake_ao collection, or the source's Drawable collection when it has one