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View Full Version : Shadow Mapping Slowdown?



Krisan
Nov 23, 2007, 06:37 AM
Well.. I don't think this is a normal performance issue, first off.. But for some reason in very specific areas, the fps drops considerably when shadow mapping is enabled. (Doesn't matter how high it is enabled, so long as it is enabled at all..)

The reason I don't regard this as a normal performance issue is.. I can have several players and mobs all casting shadows onscreen without the slightest drop in fps.. but, in any of these specific places (seemingly neutral areas where no shadows are even cast) the fps drops a ridiculous amount.. A few examples would be the GRM Store, and the Mad Beasts mission.. In the GRM store, I lose anywhere from 10 to 20 fps when looking toward the center of the room.. I can hold a steady 60fps anywhere else in Holtes city though, and even a few specific locations in the GRM store don't cause this fps decrease.. (I somewhat suspect the floor reflection is what is causing this, since in most cases.. when the reflected floor is offscreen, the fps regulates quickly.)

In the Mad Beasts example.. I can have any number of mobs on screen and stare in any direction and it is fine most of the time.. but in a few specific rooms, if I look toward certain walls (yes, walls) the fps drops from 60 to 30.. just minorly moving the camera away from said walls will bump it back up to 60 too.. this makes no sense to me and suggests that the shadows themselves aren't stressing my machine, and that something with having them enabled is conflicting with other surfaces? It is odd though.. while I can somewhat understand the GRM store if it is infact the reflection conflicting with the shadows, the Mad Beasts walls consist of only a bushy flora substance.. and not ALL of the walls in that mission cause it, only certain places of it. (Mostly corner areas, I think..)

Has anyone else experienced problems like this? It is starting to piss me off honestly, since the exact cause of the issue eludes me..

Specs:
Geforce 6800 - 256MB
AMD Athlon 64 X2 - 3800+
1.5GB RAM

ACH
Nov 23, 2007, 06:49 AM
I have the exact same problem. I noticed massive ammounts of slowdown while I was doing Fakis yesterday. But just as you said not all the time. In first person view zoomed in right at Fakis the game ran great. If I looked around I got slowdown and also if I went back to third-person. Also just now I did Mad Creatures and notice lot's of slowdown in seemingly unbusy areas. Actually it was just as you said, a wall.

Krisan
Nov 23, 2007, 07:00 AM
I noticed turning frameskip to 1, or lowering the resolution seems to resolve the problem in the GRM store.. but other areas like the Mad Beasts still cause excessive slowdown when staring at nothing more than a wall.. so I'm not satisfied with that as a solution. (Besides, I shouldn't need to do either of those things when the game runs at a perfect 60fps the majority of the time..)

Edit:
Actually, using both a combination of Frameskip 1 and a lower res seems to resolve the issue completely.. (I was only using one or the other, which individually did fix the GRM shop if nothing else.)

This is still not acceptable to me though.. I'd prefer keeping my larger resolution and leaving frameskip at 0 if I can..

<font size=-1>[ This Message was edited by: Krisan on 2007-11-23 05:34 ]</font>