texture format questions

[Dohkaviin]

Hello I have some questions about textures and photoshopping it. I'm turning the 2048 textures of tropical skyrim into 512. You might say horrible, but I am not exactly the person to look at leaves. As long as it sets the atmosphere, I'm good.

 

-whats the diff between DXT5 compression and DXT5_NM besides spelling?

 

-what are 2d textures, cubemaps and volume textures?

 

-mipmapping in textures?

Edited November 9, 2014 by Dohkaviin

[Hoamaii]

Yes, mipmapping for sure, even in 512. No idea about the difference between DTX5 and DTX5_NM (never tried _NM), but DTX5 works 100% of the time. Cubemaps help render specular lights on armors, metal pieces, eyes, etc. - you need them. But I don't know about volume textures, sorry, I never used them.

[Matth85]

" Cubemaps help render specular lights on armors, metal pieces, eyes, etc. - you need them."

 

Not quite.

Cubemap is the map reflected by your reflection/environment map. It's not needed unless you want a reflection, or got a strong specularity map( at which your model takes the hue of the cubemap as a tint.

 

A cubemap got nothing to do with reflection or rendering. The specular map ( and gloss map, which Skyrim does not utilize) and environment/reflection map does that.

[Hoamaii]

Yeah, thanks for correcting me, English is not my native language so more often than not I do not use the proper terms. But just to make sure I got you right: what you're saying is you do not necessarily need a cubemap when you have an environment map? Like if you have both specular and env map on a steel armor, you wouldn't need a cubemap?

[Matth85]

Yeah, thanks for correcting me, English is not my native language so more often than not I do not use the proper terms. But just to make sure I got you right: what you're saying is you do not necessarily need a cubemap when you have an environment map? Like if you have both specular and env map on a steel armor, you wouldn't need a cubemap?

 

Let me try to explain again. This time on my computer, and not on my phone!

 

In short, we got 4 maps to decide shine and reflection.

Specular maps - tells the engine how strong a shine is going to be. I.E. flash a light source on wood, and it bounces off light rather faintly. Do it on Steel, and it bounces a lot stronger.

Gloss map - Not used in Skyrim, as we use a less flexible solution for it. Anyways: It tells the engine how wide, or sharp, the shine from the specular is going to be. I.E. Light source on Steel is sharp, but on plastic it is matte.

Environment map - also refered to as "reflection map", as it's sole purpose is to fake a reflection. It tells the engine how much of a cubemap it will reflect. So it doesn't actually reflect its surrounding. A good example of this is Watch Dogs, and the famous mirror reflection. http://i.imgur.com/T3leCeT.jpg

Cube map - a map made up as a cube, and is used by the environment map to fake reflection.

 

So to answer you:

You do not need a cubemap if you don't use an environment map. Which you don't need unless you want a reflection.

I am unsure if having a cube map together with a specular map got any great effect, as that shine will upate upon the real time environment. So it might be void to do.

[Hoamaii]

@ Matth85: ok, you had me wondering there for a minute. So yeah, cubemaps are useful when you have an environmental map and want to create a fake reflection effect like on Steel armor for instance, that's what I meant - but I also thought that the specular map and the environment map sort of combined their effects together in the way the cubemap and the light were used to fake reflection. Maybe I was wrong about that.