Help / Edit in 3D

Smooth the terrain

Paint out lumps and noise in the ground of a map data model. Roads, parks, buildings, and trees follow.

Elevation data in cities often has the buildings and trees in it, where it was measured from the air or by radar. They print as lumps that roads climb over and parks bulge up into. In the editor of a map data model, the terrain brushes clean them up. Pick one from the toolbar and drag over the model to paint.

Smooth (S): Set to Bumps, it takes down bumps and fills dips smaller than the brush, and leaves slopes and hills wider than the brush as they are. Set to All, it evens out everything under the brush, real hills too.
Flatten (E): Levels the terrain to the height where the stroke starts, so start on a spot that's already right.
Restore (O): Paints the terrain back the way it was generated.

What follows the ground

Roads, paths, land cover, routes, and drawn shapes follow the new ground.
Buildings move up or down with the lowest ground under them, so they stay upright and keep their height.
Trees are planted again on the new ground.
Ground in water, under bridges, and under roads cut into steep ground isn't changed, so water and bridges still fit. The banks of rivers and lakes never go below the water.

Painting

Drag on the model to paint. Right-drag turns the view and scrolling zooms. On a touch screen, one finger paints and two turn and zoom.
For bumps, use a brush a little bigger than the bumps. Size and Strength are in the brush's card, and [ and ] change the size too.
Hold Shift to smooth with any brush. Press Esc, or put down a second finger, to cancel a stroke.
Ctrl+Z undoes one stroke at a time. Undo all strokes undoes them all.

Strokes are placed on the map and sized in meters, so they cover the same ground when settings change and the model is generated again.

To smooth the whole model a little, raise Smoothing for the terrain under Layers and generate again.