Mapping:Adding a camera to your map

Portals are actually fairly easy.

A portal consists of 3 to 4 objects.

First you have an object is a brush you want to be the "viewer".

Then you have 2 entities, the misc_portal_surface and the misc_portal_camera.

This tutorial also uses an entity of target_position which is used to aim your camera, although you can give your misc_portal_camera an angle to aim instead.