The online racing simulator
Mapping / mip bugs
(12 posts, started )
#1 - Ian.H
Mapping / mip bugs
Hi all,

After a long time away, decided to resinstall LFS (latest patch) but have noticed some horrible graphical bugs (see attached)

It seems dark surfaces are the more obvious and also seems to be in association with your eye level and angle of viewing the track surface as it's amplified when the road ahead drops down or when you're braking and the car dips forward.

Westhill has the same effect with a very obvious centre line.

This is caused by bad texture mapping and saw it all too often in toca rd3 conversions for other games as the road surface, like in LFS was mapped in 2 halves rather than a 1024x1024 mapped across the entire width of the road.

After experimenting with blackwood for a texture update, I noticed there's no uniform method that's been used to map the track surface at least, it seems to be done with "random patches".

The biggest worry is if there's no method within the track tools to uvmap to a spline to enable mapping around curves / corners, then remapping / fixing the tracks is going to be a nightmare.

Apparently I'm not the only one to have noticed this.

I've tried resaving the files with 6 mips and also tried various filters and nothing will even make it acceptable let alone fix it.

Is this something that's going to be addressed soon? I'd like to try and get back into racing LFS for a while if I can, but with these texture joins, it's an unpleasant experience.

I'm running a FX5900XT card with 91.47 or something drivers, 2xAA, 4xAF (8xAF made no difference either and no AF results in a sparkle-fest due to no mipmaps being used in the textures). I've tried changing the trilinear / aniso optimisation settings, clamp negative mips, but it always looks the same.

Any suggestions that I can look at are welcome


The other problem I've noticed at Westhill (only tried BL1 / Westhill for a few laps since the reinstall) is that the pit entry / exit lines (the "do not cross onto the track" lines) have some dodgy LOD values or something as they seem to appear in stages when I'm about 10' away.. quite distracting.



Regards,

Ian


PS: The XRR also sounds like a Dyson now
Attached images
mip_errors.jpg
#2 - Jakg
Mip Bias?
#3 - Ian.H
Hi Jack..

Nope, messed about with all of that (both LOD and mip) and also the mip bias from within rivatuner (currently set to -3.0). Raising this value just makes the textures blurry and then increases the visibility of the centre line but the horizontal lines don't go away.


Regards,

Ian
#4 - Jakg
Oo eck, not sure - looks like you've covered the AF route, too...
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(thisnameistaken) DELETED by thisnameistaken
#5 - Ian.H
Just watched a race from incar view at kyoto too and it happens there aswell, the word 'pit' was popping in and out.. seems all the overlaid track lines do it



Regards,

Ian
#6 - Hiwer
I have same kind of problem. It showed itself out when I updated to Patch V, U36 and all previous patches hadn't got that bug. It shows out only in Fern Bay tracks. It looks bigger problem in game, and it is really annoying. I tried to reinstall my LFS, changing graphical settings, different configurations and weather, but that bug still remains. I have AMD Athlon 2800+ processor, ATI radeon 9800 and Win XP.
Attached images
Bug.jpg
Well, personally I set "Allow negative mip bias" to "Clamp" in the gfx driver options.
#8 - Ian.H
Been there, tried that Android.. that just prevents my -3.0 mipbias from being used and makes the textures all blurry which then increases the visibility of the white centre join line but doesn't remove the glitches across the width.

I've tried just about everything I can think of from what I've recently learnt about track making but nothing seems to work mainly due to having no control of the actual mapping.



Regards,

Ian
#9 - Hiwer
I saw no difference when I changed that mipbias, but I noticed that those lines are visible also in Blackwood and Aston aswell...
It looks somewhat better on my PC, but the end of the straight on BL seems to be a severe case of the horizontal lines, and I get them down to "barely visible" at best.

The problem is that the road textures contain the white lines and often have a mix of old/new road with different colour in it, both transitions getting relatively blurred in the smaller mip levels/-maps. I once tried editing out these borders by putting a road-coloured rectangle around the edge of the small mip maps, which effectively killed the lines, but also made the white line comically disappear a bit too near (it was pretty noticeable once you knew what to look for).

I guess all this could be prevented somewhat if Eric used a different mapping method and splitting different texture parts into different files. I don't think there's much the end user can do about it (short of editing all the problematic dds files).
Ahah! found the issue but there's no sensible way for user's to fix it, it's purely down to Eric's mapping techniques. It really needs square textures per texture for the road, be it 512x512 or 1024x1024, but not patched as many textures are currently.

I just modded BWnewroad.dds again but this time took out the light patch of tarmac that occupies the top right quarter. Problem gone, although I not have silly looking dark patches all over the place amongst the lighter tarmac.

Screenshot attached of similar position to my original and also the modified dds texture for anyone else to try (NOTE: backup your original texture first if you do try it as this one's purely a test, you probably won't want to keep it).

It looks like Eric UVUnwrapped the track and the edges aren't 100% perfect and thus you get an overlap of ~1 pixel which is enough to cause one hell of a mess

I'm glad I've found the answer (don't like not knowing why things happen) but a shame it can't be fixed sensibly. The only way to eliminate it would be to make new textures but as a single shade for the tarmac, which may not be a bad thing but I happen to like Blackwood's "rough around the edges" look.. much more club-like than boring F1-style

Hopefully this can be addressed (sooner than later)



Regards,

Ian
Attached images
Snap1.png
Attached files
BWnewroad.zip - 369.9 KB - 182 views
The edges get an overlap because of the texture filtering that smoothes out the pixels, which causes bright pixels to bleed to places where they don't belong. Same thing happens for dark tarmac stripes on sections that are supposed to be of the brighter kind.

Mapping / mip bugs
(12 posts, started )
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