OCCL

Introduction

Occlusion is a feature in Vice City and San Andreas that helps make the game run smoother in certain parts of the game. The occlusions are created using invisible boxes. These boxes disable models that are behind the boxes from rendering. The occlusions are controlled by the occlu.ipl file in Vice City and other files scattered around in San Andreas. This feature is not really effective and Rockstar didn't use this feature efficiently. There are not much improvements on occlusions in San Andreas compared to Vice City. Deleting all entries in the occlu section doesn't have a major effect on your games.

Details

Format of the occlu section of the IPL file:

direct mid x, direct mid y, bottom height z, width x, width y, height from bottom height to top,
rotation

• direct mid x, direct mid y: The middle of the occlusion box in X and Y coordinates.
  
• bottom height z: The bottom Z coordinate of the occlusion box.
  
• width x, width y: The width of the occlusion box in units of X and Y.
  
• height from bottom height to top: The difference in height from the top of the occlusion box to the bottom.
  
• rotation: The rotation of the occlusion box in angles (probably radians, I'm not sure).
  

Occlusion boxes can only be viewed through (KEd).
The only known person who uses this file in modifications is spaceeinstein.

References

Occlusion Tool Temporary site to host Opius's occlusion tool