Optimisation with antiportal

[LogaN 5]

Did anyone know if the overusage of antiportals can lead to less fps or is this not possible.
I ask, because I am working in the moment on a forrest and so I am getting more and more into a situation where my frames per second turns into seconds per frame. So make it sense to fill every trunk with an antiportal?

greetings and "guten rutsch" (some kind of the german version of happy new year).

[Scourgem]

Well... I guess it could get out of hand if your antiportals are numerous and/or very complex - they're a kind of BSP brush, after all, and as such they may contribute to the node count.

I'm not sure, really. :p

[Scourgem]

Ahh, here - I've found a much more detailed explanation. It was originally posted by Checker on the NaliCity boards - looks like he knows what he's talking about.


With that much BSP you might want to keep a close eye on your traverse time in stat render. (also set up time)

Traverse time is the time the engine needs to figure out what the render, and what not to render. With lots of BSP and antiportals the travers time can sky rocket and kill your level. Take a look at Scorched Earth, i had to convert almost everything that was BSP to staticmesh, except the outer shape. I even made the BSP in lightwave so it would be as clean as possible.

Only way to not get huge traverse time is to have lots of zones, and this creates a room corridor room corridor sindrome. If you want lots of detail, you need to zone alot, which can be a bitch :/

Antiportals are really handy, if they are huge, and you only have a few. Each staticmesh needs to be checked per antiportal per frame to see if you need to render it.

[HortonsWho]

Speaking from experience--- I have a largish forest in my work in progress... I put in lots of blocking volumes (another brush type) so that I could turn collision off on the trees themselves... it really drained FPS... so yes, AP's volumes, etc can have a negative effect.

[Blitz]

I used blocking volumes around meshes too, and it seemed to help slightly. I noticed on some Epic maps that they did this, but didn't bother to change the collision on the meshes themselves. Anyone know if the BV benifit is still there if the mesh inside is at default collision? I turned off most of the collision on my meshes.