Demo Normal Maps

[Mitovo]

Hi all,

So, I'm curious about something. I've been poking through the art files for the different demos made with T3D, and I'm noticing something with the normal maps, particularly those used for Deathball Desert. I'm noticing that, when I look at them in WTV, the normal maps are all shades of purple, none of the green or blue that usually shows up in a normal map.

Does anyone know what software was used to generate those? And also, how are they working as normal maps with only the purple? I always thought the different colors in a normal map represented the angle of a pixel at a given point.

Thanks

[Duion]

Probably dxt5nm format also called swizzling. It shifts around the colors to avoid dds compression artifacts. I use that for most of my normal maps, but when I open them in Gimp they look normal again, it is just in WTV that they look weird.

Another cause or weird looking normal maps is if there is an alpha channel with low intensity so that the texture is transparent which changes the appearance of the colors as well, you can see this on the normal map for the default soldier, it is almost transparent.

[Mitovo]

Probably dxt5nm format also called swizzling. It shifts around the colors to avoid dds compression artifacts. I use that for most of my normal maps, but when I open them in Gimp they look normal again, it is just in WTV that they look weird.

Another cause or weird looking normal maps is if there is an alpha channel with low intensity so that the texture is transparent which changes the appearance of the colors as well, you can see this on the normal map for the default soldier, it is almost transparent.

 

I see. Interesting!

Yeah, that really threw me off looking at it, because I'd never seen a normal map look like that before.

Are there particular settings folks would recommend for normal maps used in T3D? The ones in the demo materials look really good, and I've seen others get some really nice results. I never seem to get quite as much "depth" in mine as I see in others'.

[Duion]

Use dxt1 whenever possible, it has the highest compression.

For normal maps you can use dxt1 as well but you will have compression arftifacts, so you have to use dxt5 or dxt5nm.

For textures with sharp alpha use dxt3 and for soft gradient alpha use dxt5. So cutout plants can use dxt3 and semi transparent clouds can use dxt5.

When in doubt just use dxt5.

I use dxt1 for diffuse and specular and dxt5nm for normal maps.

If you want to use parallax textures you need to put the heightmap into the normal maps alpha channel and save it as png, since dds are broken with that feature.

[Mitovo]

Very nice.

Cool, thanks for the info! Will keep that handy for future reference.