Fix many BSP problems caused by complicated brush (terrain for example), not on grid
1. Set grid to size 1.
2. Select problem brush.
3. in context menu choose
Polygons -> Snap vertices to grid.
Also you can do this with selected all brushes - can be solution for many BSP problems.
Also you can use grid less from 1, like:
MAP GRID X=0.125 Y=0.125 Z=0.125
but always keep it on power of 2: 1/2, 1/4, 1/8 etc.
Change map mover textures properties (align, flags) without rebuild level
Useful for edit level with removed brushes.
1. Save map with some temp file.
2. In context menu of movers:
Movers -> Snow polys.
3. Change surface in desired way (align, flags).
4. Copy selected mover.
5. Open temp file, without save current changes.
6. Paste copied mover.
7. Delete old one and fix offset (32, 32, 32) for pasted one.
Recreate mover BSP
Sometimes you need recreate mover BSP if you change it. For example rotate.
(If you rotate flat door you can find collide box on same place as before, while visually it appear in proper place.)
Exists few ways:
1. Copy and paste back.
2. Duplicate mover.
3. Copy polygons from mover to builder brush and add mover again.
After make new mover, old need delete.
Move Brush (Mover) Origin
1. Select desired brush (Mover).
2. Enter into vertex editing mode.
3. Select all vertex of brush.
4. Move it in desired position against Origin (you can see Origin as unselectable vertex).
5. In normal mode move brush (mover) where it be back.
Delete actor duplicate by name
1. Select and delete duplicate actor.
2. Save map with some temp file.
3. Load map from temp file.
4. Repeat until only one actor per name left.
After time in actor list created gaps. For remove such gaps need send to first or last any actor.
I suggest use for this Player Start. Send it to last.
Also this able speed up path rebuilds and all iterators over all actors.
So this strongly suggested before make public release of map.