Performance killing GFX glitches

[Zordak]

Hi,

At least since the last hotfix, maybe even longer (i played a little with the game gfx settings and some game.cfg settings [though mostly i tried to find the optimal _fov for me] in the meanwhile and have not noticed the specific moment when this turned up) i have a very annoying graphic bug.
Image 1: Bug version 1, fps drained
Image 2: A few seconds later, bug gone, fps restored

The center of my character suddenly gets linked to the edges of meshes of characters and monsters - but not static elements - around me.
Actually there is 2 different variations of this: One "connects" me with every interactive model and also seems to interconnect the mesh of my character itself. This causes my fps to decrease from fluid ~60 to <5-15, rendering the game unplayable.
Another is selective to types of meshes. For example connceting me only to a forts archer guards. Or only to the faces of mages around me. This one is annoying, but does not have much impact on performance.
Both bugs come and go from what i can tell totally at random. Besides being annoying since i only see black stripes of ppl, the performance drain with the 1st version of the bug makes playing impossible.

On top of that i quite often get what seems to me "displaced meshpoints".
Image 3: Deformed mesh of my staff
Here the texture is applyed to the deformed mesh. This bug also appears to random objects. But if one object has it, all objects within my view range will share the same deformation. This is usually only ugly - and also irritating since its viewing-angle-dependent - but only in rare cases has any impact on the performance.
Image 4: Slightly tilting the viewing angle lets the bug disappear
This apparent disappearing is probably only a result of the texture being infinitesimally thin, so its just invisible from the right point of view. But thats my guess.

Some specs of my system to complete the report:
OS Arch Linux, Kernel 2.6.32
Geforce 7900GT with 190.53 module
Athlon X2 4200

Game was set to shader model 2.0, no shadows, all details except the textures are off/at minimum.
The only change to my game.cfg i can recall with certainty is setting the vg_fov to 75.

Since i cannot switch the error on and off at will i have not started investigating all game settings combinations. Also the last "displaced meshpoint" problem is not necessarily correlated - i have seen this also in wine applications and i tend to blame the nvidia driver for it. But since I lack the technical knowledge i filed it here as well.

Anyways, help getting rid of this problem would be very appreciated.

Z.

[Zordak]

This seems not to be a game bug but rather a problem with libpng1.4.
Installing libpng1.2 and preloading it seems to have fixed the issue.

Thanks go to Nightchill for proposing this.

Z.

[onemyndseye]

Nice find bros!