How to optimize your map?

  • Ok. It is time for optimizing our maps. But where should i start?
    What are the most “expensive” parts in a map?
    I found out cull volumes are good and using only collision where it is needed.
    What next?

    • Should i reduce some pointlights? some particle/weather effects?
    • Do i have to many trees/grass/stones in my map?
    • What about optimizing kismet? Is “sent NPC A-> X” better than “sent NPC A->B” + “sent NPC B->C”+…+“Y->Z”. Should i care about loops? etc.
    • Does levelstreaming have advantages?

    Plz tell me your secrets :-)

  • Make sure you don’t have any massive view distances leading to lots of meshes loading. Use DistanceCulingVolumes to strip out everything of certain sizes at range.

    The big hole in UE3 is lighting however. Try to minimise using dynamic lights, they really will stress your system out.

    Make sure you are using lightmaps whenever you can, and that they are as small as you can manage. This is less of an issue with as much video ram as people have these days, but it’s still worth keeping any eye out for.

    AI is another issue. It’s CPU based and can result in bottlenecks. It seems like modifying AI targets causes a jump in CPU use. For example if you try to order your AI to defend a point when it gets attacked it can impact performance as 16 or so bots suddenly need to recalculate their path.

    Emitters can be quite heavy but only if you go completely crazy. Most of the standard emitters are fine as long as you don’t have like 30 or more in a small area.

    Really the only secret is be conservative. Save where you can and focus on high traffic / important areas that.

    Don’t bother with streaming. It serves very little purpose outside a single player environment (or if you are working in a team of people). You CAN get some extra performance out of it but the overhead is too large to be worth doing on a MP map.

  • Here is a tutorial I wrote a long time ago. This was written mostly in 2007 or 2008 I believe so some of it is outdated XD

  • Damn man, I feel so inexperienced, I only started using UDK 4 months ago 3 3/4 months ago :P

  • Well i think in my map the rain is a fps killer + massive view distances. I give cull volumes a try.
    I have some peasants running from a to b, but max 15 guys shouldnt do so much calculation, I guess.^^

    Thanks for your suggestions!

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