How to use Clip Planes

[palistov]

Add it by clicking the plus sign. Click the XZ, YZ, or XY button, whichever it is. This changes the orientation of the plane. Next change the height of it. The height corresponds to the discluded letter in the orientation. An XY plane will move horizontally along the Z axis, and the YZ plane will move horizontally along the X axis, but a XZ plane will move vertically.

Clicking the Pos or Neg button changes which side of the plane is culled. Any objects that aren't fully crossing the plane on the side which is to be culled are not shown. If an object passes that point even slightly it will still be shown. It has to be completely past it to be hidden.

I'd suggest putting your clip plane in the middle along a YZ or XY plane, then swapping between positive and negative culling as needed. This way you don't clutter your map with clip planes

Good luck