OrbWeaver on 16/12/2005 at 17:00
Quote Posted by Skynet
Then how about replacing the normal map images with blank images.
The worst of both worlds - you've got the ugliness of bumpmapped-textures-with-bumpmaps-disabled alongside no performance gain (because a flat normal map takes just as long to render as a bumpy one).
Quote Posted by ZylonBane
The difference between bump maps and normal maps.
Renzatic is correct insofar as "bump mapping" is a generic term for the technique of perturbing a surface's normal vector to simulate bumps. Although it is commonly used to refer to elevation maps, as described in that article, it doesn't have to be.
Other forms of bump mapping include embossing and environment-mapped bump mapping (EMBM), which were described in quite a good article I cannot locate at present.
Ziemanskye on 16/12/2005 at 18:05
Does anyone know about texture scaling/comparisons...?
I mean if you have a 1x1 (or 16x16, or whatever the minimum size is) for the "blank" normal map will that still reduce performance as much?
Yeah it'd still be ugly, but maybe it'd acclerate things a bit (because each pixel (texel?) of the normal bump map is so much larger than before)
OrbWeaver on 16/12/2005 at 18:45
You would save texture memory that way but I would not expect much impact on frame rate in most games. However, based on other people's experience with ascottk's high res textures (and associated performance drop), it might be worth some investigation.
You would not normally want to downscale the normal map too much though, as the resulting blockiness can become rather obvious. Downscaling the diffuse is much cleaner.
John P. on 16/12/2005 at 20:38
You could comment out the names of all the normal maps in the .ibt files. The game would then look to the DynamicallyLoaded folder for replacement normal maps, but wouldn't find any(unless you put some there obviously), and so would not load anything(except perhaps a 'badtexture.dds' file, not sure). It's pretty tedious, time consuming manual labour to do that though.
As has been mentioned, some of the (original) normal maps have details in them that are not in the diffuse, and so it may look weird when those details are missing.
kamyk on 17/12/2005 at 17:43
Quote Posted by Komag
Even the lowly GeForce 5200 will run better.
I can attest to that!
Fingernail on 17/12/2005 at 17:48
actually what we have here is a 3 way distinction.
Bump mapping is a rather loose term which can be used to describe, among other things, normal mapping
and height mapping (or ELEVATION mapping as that article rather prodigiously names it). You could also use it to refer to parallax or displacement mapping, but since the effects of these are rather different to height and normal maps, they're usually singled out. Normal and height maps have similar, but importantly different effects.
Normal maps encode the information in RGB to represent vectors, height maps are just grayscale images where white = high and black = low. Thief 3 uses normal maps, although you can convert heightmaps to normalmaps quite easily, so it's very possible that for some details heightmaps were used to source the normalmaps. Certainly Doom 3 converts heightmaps at runtime, which means you can effectively use both. However, you can't get a smooth gradient with heightmaps due to the innaccuracy of the grayscale information.
ascottk on 17/12/2005 at 17:58
T3 can use bump maps as well as normal maps. The bump maps are not as accurate like fingernail says.
Adam Seijuro on 28/12/2005 at 07:26
Yeah, most likely I'll need to get a better graphics card at some point. It really does suck! Fine for older games (just got ahold of Thief Gold, gonna get stuck in to that shortly), but newer games just die in the ass no matter how low the graphics :(
My CPU is an Athlon XP 3200+ btw.
Thanks for the replies people :)
