What causes you frame rate drops?

SubJeff on 5/9/2005 at 11:18

I noticed a big frame rate drop as soon as I added a skybox. Is there anything that people notice causes a big drop in rate?

Gonchong on 5/9/2005 at 11:47

- Getting more AI's patrolling.
(Anyone know a way to make them more effiecient? (like dromed's 'Efficiency Settings')

-Testing the mission without making sure that the bsp and flesh builds are up to date. (Kills the frame rate!)

ProjectX on 5/9/2005 at 12:04

Large areas with lots of shadow-casting meshes, particles and a skybox.

So far that's the only thing that's made me notice a framerate drop on my GeForce 6800 GT.

Crispy on 5/9/2005 at 12:10

MONSTROUS, WORLD INGESTING STENCIL SHADOWS™ cast by BSPs, as described here: (http://www.ttlg.com/wiki/wikka.php?wakka=PerformanceTips) :p

I was getting about 5 FPS on my simple two-room test level - turned off shadowcasting on the outer walls of the level, and it jumped to 15 FPS. (Still not great, but I was regularly getting ~12 FPS in the OMs. Yes, my computer is slow.)

Caseus on 5/9/2005 at 13:17

I have noticed that setting my User.ini using the method some have recommended causes huge performance loss. I however didn't notice it until I added my skybox. My level was not overly large or well lit at this point but was absolutely crawling to the point I could barly turn the mouse. I deleted ALL the lights, and ALL the skybox save for the Skybox actor, mesh and the box itself and my framerate had been crawling still.

After re-zoning, playing with BSP builds etc (several hours) I finally clued in that I had tried playing with the user.ini settings in order to get the FM's to actually run. I did what most were recommending, added a zero to each pool. So i suspected this as the problem.. Opened the user.ini and used calc to actually calculate the values to double their size as opposed to just adding a zero and the problem went away. I ended up with the following values.

[PCVertexPools]
DynamicVertexPool0=6291456 ;originally 3145728
StaticVertexPool=5242880 ;originally 2621440
StaticShadowVertexPool=3145728 ;originally 1572864

Now Im not sure why setting them by just adding a zero causes huge lag for me but this setup eliminates all performance Issues I have so far. And my Indoor/outdoor level is quite expansive and I am still having no trouble whatsoever.

Ziemanskye on 5/9/2005 at 13:21

12 in the OMs?! Lucky you, I average about 7, though I built schism to not drop below 10 on my system (it still does, but only in the one place, so I was willing to let it slide).

Main thing that usually kills frame rates for me is lights - even non-shadow casting lights are expensive. Directionals seem the worst because the length property only applies to the shadow, not how far the light actually goes, with vertex amibients the cheapest I've got to work.

That or lots of alpha textures - try looking through a whole tree worth of leaf hemisphere smeshes, made me crawl (also made me drop a level I was working on, though the church on the side of it grew up to be the Schism cathedral)

Lots of particles, though you can often tweak the individual emitters to shave 5-10 particles of the count and that helps (quite a lot if you do it 5-10 emitters, each with 2-3 parts you trim, all in one area)

A skybox (though that might have been the Alpha thing again, it had 3 levels of cloud). Massively screwed Schism out of it's original configuration because of that self-imposed performance limit, though really the place is probably better for it.

Shadows, naturally.

Poor zone occlusion - having lights shine through walls not only looks bad, but means more lights rendering which means lower frame rates. Same goes for particles. Unfortunatly though, more portals also eventually hurts performance, so you need to be kind of frugal on both.

Staticmeshes. More than about 75-100 in a scene and the place starts to slow down, even without shadows. You've seen how I like to build, so I'm sure you can understand how much that annoys me. At least in UT2k4 you could "Convert to StaticMesh" other groups of smeshes, so the whole group becomes a single object and improves performance that way.

Lots of AIs in an area. They do get more efficient if far away, but having too many close together makes the rate drop.

The main one for me though, is always the lights.

SubJeff on 5/9/2005 at 14:04

I think it might be my meshes too. I have a fair few in a small area because it's a wooded and grassy grove. Hmmm. I might have to do some redesigning.

ascottk on 5/9/2005 at 16:30

I added this note to Labyrinth Beta 0.7:

There was a corrupted brush (second floor room's window that used to look outside) that acted like a bridge between two zones. The zones merged & that room kept rendering even though I thought I totally sealed the room off. This was one reason why outside performance was terrible.

Quote Posted by Caseus

I ended up with the following values.

[PCVertexPools]
DynamicVertexPool0=6291456 ;originally 3145728
StaticVertexPool=5242880 ;originally 2621440
StaticShadowVertexPool=3145728 ;originally 1572864

Now Im not sure why setting them by just adding a zero causes huge lag for me but this setup eliminates all performance Issues I have so far. And my Indoor/outdoor level is quite expansive and I am still having no trouble whatsoever.

I ended up with the same values. I also notice some odd brush rendering when I go into flesh wireframe mode:
Some surfaces fade in & out in certain areas. It only fades in when I look at it from a certain angle.

Caseus on 5/9/2005 at 16:55

Quote Posted by ascottk

I noticed a similar problem with fading and odd behaviour while in wireframe (Flesh) mode. I had atributed it to not having all the zones hashed out as of yet. My level is not fully complete so I figured I would solve some of the recurring BSP problems at the end of my build. I wanted to get all the basic BSP and Lighting done beforehand and then worry about the bigger BSP problems. I had noticed that some BSP problems only show up after I do my first build when loading the map. Prior to the first build the BSP (HOM) disaperaing walls etc do not show up. I read a tutorial on Unreal ED BSP and it stated that during a map load the BSP process is more refined than when you are generally just adding brushes and doing a build all. And that often exporting a map to .t3d then reimporting can fix ceartain BSP probles that are Intermitent and have no aparent cause. For example, the front of one of my Buildings always has a disapearing face (front wall). On a fresh map load this problem is not present, but adding brushes and hitting build all brings it back. Not sure how I am going to solve that one but i'll just put it off for now, as I have already rebuilt the entire area 3 separate times and the sampe problem occurs. I'm beginning to thing the Flesh addition to the Unreal engine has made it quite picky about BSP architecture.

While I still don't have a lot of performance issues, I find that the meshes can be place anywhere without any severe performace hit, but simple BSP architecture (ie: an underground tunnel) results in a TON of BSP errors and HOM's all over my map. So I have been keeping the Arctitecture simple only using a few cylinders and mostly comprised of rectangles enhanced whith lots and lots of meshes.

Im getting great performance now with a map thats at 80% complete. I am however waiting longer and longer for it to Load :D

OrbWeaver on 5/9/2005 at 17:53

Quote Posted by Ziemanskye

12 in the OMs?! Lucky you, I average about 7, though I built schism to not drop below 10 on my system (it still does, but only in the one place, so I was willing to let it slide).

That sounds like what I used to get while playing TDP on a P166 with no 3D card. If I shot a zombie with a fire arrow the computer would spend two seconds thrashing the hard disk followed by an explosion at about 2 FPS.

Nowadays, if I get less than 22 - 25 FPS I'm either dropping a resolution, upgrading the graphics card or just playing a different game.