OK
Consider that right now (I've sent you a PM about this) I'm just resizing the textures BUT applying the original DXT, so if you have any advices (especially if I can use DXT1 in place of DXT3/5 in certain textures) I'll be more than happy, I would save a lot more vram (DXT 3/5 uses almost double space than DXT 1 )

In Skyrim, normal maps need alpha channels. The normal map's alpha channel is what defines specularity.

So diffuse maps can all be saved as DXT1? BTW I've encountered in HD dlc some normal maps (suffix _n) saved as DXT1... do you know why?

Unless I'm mistaken -- Skyrim still uses the normal map alpha channel for the Specular map -- what you are thinking are specular maps are environment maps not specular -- so deleting teh normal maps alpha channel is going to mess things up -- not sure if a missing alpha would default to pure white which would make all objects very reflective or all balck which would make them not reflect light at all --- If you want to test this remove the alpha channel from any armor texture and use it in game and the armor will either be very reflective or will disappear completely (since the in game lighting will not reflect)

Not all diffuse maps can be saved as DXT1. There are a lot of diffuse maps that contain transparencies, which work best saved as DXT5 and will look terrible saved as DXT1.

Which vanilla normal maps were saved as DXT1?

Depends on your paint program I think. But defaulting to pure white or pure black are both very bad results.

For example barkeepfemaleoutfit_n in the first HD BSA @ textures\clothes\barkeeper\f

http://imgur.com/GccP6

Specularity is controlled by the mesh that texture is used on. Which means on that particular trishape the specular data is the same throughout. It could be improved using an alpha channel.

I've finished optimizing the package HDtextures01. I don't think I'll do the same to HDtextures02 which contains textures for architecture and landscape. maybe just a 'quick and dirty' version of it which will require far less work.

Higher resolution normals have less impact in Skyrim than changing the diffuse layer to higher resolution maps. So I basically removed all the normals.

By converting all the textures from DXT3 to DXT1 (when the alpha layer was nothing but black and white) I've saved nearly 400MB. Clothes, armors, (most) animal skins still use 2K textures. Weapons were downsampled to 1K. Small piece of garments (boots, hoods and gloves) were kept vanilla sized although using 1k for gloves will benefit those who use 1st person view.

All the mipmaps have been redone from scratch using the highest quality algorithm possible for resampling.

Package size is not 450MB versus 2GB of the original. I'm pleased about the result because (as far as clothing, weapons, armors, etc...) the end results is very close to the package distributed by Bethesda but it runs far smoother on my laptop.

I'll have it uploaded in 8-12 hrs. I tried the whole weekend but the Nexus servers kept bumping me off.

File is up on the Nexus, if anybody wants to give a try and has a fast connection (450MB).

http://skyrim.nexusmods.com/downloads/file.php?id=10239

So far, only HDtextures01.bsa has benn "converted". I don't think I'll do the same with the second file because there are better MODs around fixing the worst textures in some cities (Windhelm being the worst) and Bethesda textures, unfortunately, do very little .

Updated version is now available. Fixed some problems with textures in the wrong directory inside the .bsa and a few visual glitches due to "excessive" optimizations regarding the alpha channel.

Isn't this the same thing?

http://skyrim.nexusmods.com/downloads/file.php?id=9080

Just wondering!

Yeah... it's already been done. Unless this one is even smaller...

I am interested in this.

There are 2-3 packages like mine each with a different approach. In my case, I tried to preserve 2K resolution textures whenever possible by dropping normal maps entirely (so meshes will sue the vanilla ones instead) and converting several DXT3 textures (4:1 compression) to DXT1 or DXT1a (6:1-8:1 compression) when the alpha channel wasn't needed or was only a black and white mask.

Weapons (which are mostly 2K in the official package) were reduced to 1K (still 2X than the original) because since this package is aimed at old graphic cards, people who don't play at fullHD resolution won't notice a big difference. Likewise, a few other textures applied to small meshes were re-dimensioned or left out since they hardly contributed to a noticeable increase in quality.

Working on this package, I noticed how artists' work at Bethesda is a bit... hectic. There are three or four naming conventions adopted for the files; some textures are dumped all in the same directory, sometimes a female/male directory is used for variant. Shield are sometimes classified as weapons, sometimes as armor. Coupled with the fact that several textures that could have been compressed to DXT1a were DXT3 instead, there was a lot of room for optimization. There are even a few (mostly unused) duplicates.

At any rate, this package works very well on my laptop with an ATi 4650 in it. I play at 1360x768, all detail set to the max (except shadows) and with 2x antialiasing too.

This package only contains textures from the first of the two files Bethesda distributed, thus only clothing weapons and armors. The second package contains textures used by the game world but, again, I feel Bethesda made a bit of a rushed job and this package doesn't dramatically alter the look of the game especially, where is truly needed so I left it out and I don't think I'll ever start working on it.

No, it's a different thing

My mod is an optimization of the entire Hi-Res DLC BSAs (resizing when possible), while msxyz is doing an even harder job with his mod, changing the DXT compression when possible and keeping the HD textures just when needed

I've tried it and works great, give it a try guys