Fix - Large Brushmodel Flickering/Not Visible

[mh]

In case anybody missed it:



There is a problem with many Quake engines where extra large brush models go into too many leafs during the process of the server determining which entities to send to the client. Quake sets a maximum of 16 leafs which an entity can be in, and if all 16 of those are filled by leafs outside of the PVS, then the entity won't be sent.

This is not necessarily restricted to brush models and could in theory also happen with MDLs, although in practice I have never seen one large enough to cause the problem. It could also happen if QBSP carves your map up such that there are more than 16 leafs butting together close enough in a tight area, but I'd expect that's quite unlikely.

The original thread linked above contains a discussion of the problem, various methods of fixing it, and sample code for one method of fixing it (derived from DirectQ; this will have to be adapted to your own engine, but it should be quite evident what needs to be changed).

The code given is by no means the only way or the best way, but it has been in production for over a year and has been proven to work with a specific incidence of the problem.

[revelator]

[revelator]