Anything mappers can do to optimize occlusion culling performance?

Mr. EpicMr. Epic Join Date: 2003-08-01 Member: 18660Members, Constellation
edited January 2011 in Mapping
<div class="IPBDescription">tips/tricks? Dev thoughts?</div>While investigating the performance of some areas it seems the occlusion culling system has the biggest impact on whether an area performs well or not. I have a hallway that is mirrored on both sides, and when facing the sides of the hallway (such that I am not looking down the length of it) the side with other rooms and junk behind it is about 20fps lower than the side without. When I run wireframe mode to check what is being drawn sure enough the rooms behind it come in and out of rendering quite frequently. It doesn't seem to matter what geometry is separating the areas, though at certain angles the other rooms and items are properly prevented from being rendered.

Are there any tips/tricks mappers should be aware of to cater to the occlusion culling system? Are there distance considerations, angles, or anything else we can possibly use to our advantage while putting the maps together? Thanks.

Comments

  • MaxMax Technical Director, Unknown Worlds Entertainment Join Date: 2002-03-15 Member: 318Super Administrators, Retired Developer, NS1 Playtester, Forum Moderators, NS2 Developer, Constellation, Subnautica Developer, Pistachionauts, Future Perfect Developer
    We'll be doing some experiments soon with some new tech that will hopefully improve occlusion culling performance.
  • Mr. EpicMr. Epic Join Date: 2003-08-01 Member: 18660Members, Constellation
    <!--quoteo(post=1827611:date=Jan 26 2011, 07:19 PM:name=Max)--><div class='quotetop'>QUOTE (Max @ Jan 26 2011, 07:19 PM) <a href="index.php?act=findpost&pid=1827611"><{POST_SNAPBACK}></a></div><div class='quotemain'><!--quotec-->We'll be doing some experiments soon with some new tech that will hopefully improve occlusion culling performance.<!--QuoteEnd--></div><!--QuoteEEnd-->
    That is great news, hope they go well. The performance has gotten really good when this factor doesn't come into play, so here's to making it better :)
  • SN.WolfSN.Wolf Join Date: 2010-03-29 Member: 71115Members
    big "smiley face"!!!

    I did notice that the sky-buildings are a big slow down for me, i can't speak for everyone but that's my experience.
  • RebelRebel Join Date: 2003-04-10 Member: 15371Members, NS2 Playtester, NS2 Map Tester, Subnautica Playtester
    <!--quoteo(post=1827611:date=Jan 26 2011, 07:19 PM:name=Max)--><div class='quotetop'>QUOTE (Max @ Jan 26 2011, 07:19 PM) <a href="index.php?act=findpost&pid=1827611"><{POST_SNAPBACK}></a></div><div class='quotemain'><!--quotec-->We'll be doing some experiments soon with some new tech that will hopefully improve occlusion culling performance.<!--QuoteEnd--></div><!--QuoteEEnd-->

    YAY! you are a genius.
  • Evil_bOb1Evil_bOb1 Join Date: 2002-07-13 Member: 938Members, Squad Five Blue
    Is there any update on this? has it been implemented yet?

    I've been observing that a lot of my geometry/props are rendered from rooms across the map.

    An explanation of how the occlusion culling works would be nice as well so I know how to work with it.

    Even if it is 'automatic' it would be nice as well to be able to help it out like vis blocks from hl engine.
  • pSyk0mAnpSyk0mAn Nerdish by Nature Germany Join Date: 2003-08-07 Member: 19166Members, NS2 Playtester, Squad Five Silver, NS2 Community Developer
    Some props don't cull properly and sometimes there seems to be trouble with brushwork that is not tied and welded together, which happens when you copy&paste&transform faces a lot.
    In that case vertices are not on the grid (floatcomma) even though the editor shows they are.
    You can spot those vertices by checking adjacent lines and faces for scales that are supposed to be "0" but show "0.01", for example.
    Also textures on those faces don't use the exact scale they are supposed to (1.001 instead of 1); sometimes you even need another angle than 0°, because some vertex is screwing up the face orientation with its minor, not shown floatcomma values.
  • Evil_bOb1Evil_bOb1 Join Date: 2002-07-13 Member: 938Members, Squad Five Blue
    Thanks pSyk0mAn for the answer, helps a lot. My geometry is in one piece and falls on the grid (I will check more in detail in I don't any .1s) I have a lot of 45 degree angles, some problems might come from there. I've split the geometry up a bit and took the occasion to move rooms around, create more space between my rooms and added meandering corridors and the occlusion culling was working much better even if some things should definitely not be showing.

    I've noticed my problems are more frequent when there is a fin void between two walls, even if they have no visibility from one room to the other, (they connect from other rooms). Something to look out for.
  • ThaldarinThaldarin Alonzi&#33; Join Date: 2003-07-15 Member: 18173Members, Constellation
    Easiest way to show that is run around in alien flashlight. You'll notice 'x's at the seams of said geometry and at points inside props.
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