--PSSM shadows must be deactivated before changing the video resolution or video mode, or when loading a level or changing the level size. Activate them again one frame afterwards.

--On the other hand, PSSM shadows require careful adjustment of the shadow bias (pssm_fbias, see below) and the camera clip_far value to the level size and type. Wrong values can cause artefacts such as "surface acne" or displaced shadows.

--The light source is the sun, as set up in the level map or in the script (sun_angle).

--Only objects that cast PSSM shadows can receive PSSM shadows. For this reason, the SHADOW flag should be set for level geometry and terrain.

--PSSM shadows must be deactivated before changing the video resolution or video mode, or when loading a level or changing the level size. Activate them again one frame afterwards.

--They should be deactivated when the player enters an indoor area (otherwise, everything indoor would be in shadow).

--Before activating PSSM shadows, set shadow_stencil at 8, and set camera.clip_near as high and camera.clip_far as low as possible. Make sure that level_ent.max_x and level_ent.min_x reflects the final level size.