SSE Texture Compression and You. [Skyrim SE Edition]

[crazylion]

While that may be true factually, it's been my experience that modders primarily save with DXT1 or 5. I have another program that allows me to view image types. I don't think I've ever run across anyone saving anything with DXT1a or DXT3. This applies to the default images used in both versions of Skyrim as well: if it has an alpha channel, whether that is a complex grayscale or just dual black and white, it's DXT5; if it doesn't it's DXT1.

 

It's the difference between what can be done and what is done by the majority of people making mods, and even by the developers themselves.

Ok in that sense I fully agree, personally I also use only DXT5 just because I seem to have less artifacts in it as DXT3 for no apparent reason (maybe because of the converter). Only for the low quality versions I use DXT3 or DXT1 or DXT1a.

As for DXT1a and DXT3, yes I can see them a lot in the original game files for obviously resource saving reasons. Did you run any texture optimizer software which does convert files to DXT1 or DXT5 (but DXT5 does actually not improve the files quality that would be only possible if you would create a dxt5 from the original file uncompressed)

 

CL

[Nemain666]

I never understood that with the compressions and I use Gimp.
So far I have everything that I have edited for my use, always saved in BC3 / DXT5 and it worked.
Now for the first time I had noticeably many textures that Gimp could not open-> BC7?
After a tutorial video "Modding Tutorial - GIMP + DDS" by Shaostoul, I successfully connected the Equinox dds plugin with the Texconv.exe from SSEEdit.

Now my gimp can also open the previously impossible .dds.
But if I want to save now, I have no choice, so probably everything in BC7.
Is that ok? Or do I have problems with my game when all of my edited .dds are now BC7?

[crazylion]

Hi

you can do every texture in BC7 as SSE supports them full there will be no issue.

 

CL

[antstubell]

Old post, I know but I'm late to the party.

Is texture compression necessary? All the textures I am using have no compression. Is there any advantage, apart from size to compressing textures and what options should I use, if I use compression?

Using Gimp.

[nightscrawl]

Old post, I know but I'm late to the party.

Is texture compression necessary? All the textures I am using have no compression. Is there any advantage, apart from size to compressing textures and what options should I use, if I use compression?

Using Gimp.

 

Yes, it's about size.

2k (2048x2048) is the most common size seen in texture packs. An uncompressed 2k with no alpha is 16.3 Mb; with an alpha it's 21.8 Mb.

4k (4096x4096) is growing in popularity. An uncompressed 4k texture is 65.5 Mb; with an alpha it's 87.3.

You could very easily eat up over 1Gb of your card's memory by having a full set of uncompressed character textures.

 

Those are very large file sizes. Many people put up with them, especially in Oldrim, for character normals. That is, the normal maps that are associated with the character skin textures, because the quality of character aesthetic is highly valued, particularly in the Skyrim community. But that amounts to a limited, fixed set of texture files -- one uncompressed normal for each gender's face, body, hands, and feet, plus an additional face normal for all of the races.

 

Having uncompressed textures for large texture packs that make over Skyrim itself would eventually become untenable and degrade performance as the graphics card struggles to keep up. It's just too much space for hundreds of files.

 

The majority of diffuse (the part that we actually see in the game, skin, etc) textures, can be compressed with no issues, as the artifacts of compression just look like natural noise, such as you would see on a photo of skin, or a tree, and so forth. Diffuse textures with smooth gradients, like sky and some metallic surfaces, should not be compressed because compression artifacts will ruin the gradient.

 

With normals, it depends on content. Again, with a heavily textured object, like a tree trunk, artifacts matter less.

 

With Skyrim Special Edition, as well as many newer games -- it seems strange to refer to Skyrim-anything as "new", but it is in this context -- we can use the newly developed BC7 compression. This affords the same level of compression as older DXT1 and 5, but with the artifacts reduced by around 99% (they still exist), so it's not noticeable at all outside of super zoom inspection on any given texture. BC7 is the future for game textures and will improve texture quality across all games dramatically -- it's freely available; there is no reason for any game studio not to use it.

 

With BC7, the game modder is limited by the software they have access to. Photoshop users can use the Intel Texture Works plugin. Until relatively recently, GIMP users were out of luck, as that could only support the older dds plugin; I found this link, people are saying it works, so you can give this a try.

There are also other texture utilities that allow for conversion outside of the image program itself, such as TexFactory.

 

 

As for texture formats:

DXT1 / BC1 is for textures without an alpha channel.

DXT5 / BC3 is for textures with an alpha channel.

Both of the above can also be saved with the newer BC7.

Linear or srgb (in the save options) depends on the requirements of the game itself. I'm pretty sure linear is fine for Skyrim.

 

Ideally, you will want to compare to the default Skyrim texture for whatever it is to see if there is an alpha channel. Some modders save as DXT5 mistakenly thinking that is higher quality, when that only adds a useless alpha channel that only takes up memory. Hell, even some of the default game textures do this; you will know it's useless when there is a solid white alpha.

 

Now, one drawback is that BC7 can mess up alpha channels, so don't go using it for everything; be thoughtful.

See here: https://forums.nexusmods.com/index.php?/topic/7405686-pixel-compression-on-bc7-alphas/

 

In addition, don't go converting every texture you use to BC7. If you have textures that are compressed, that image information is lost forever; converting it to BC7 will not gain anything. The only benefit you will see from using BC7 is if you have the raw uncompressed images, either from a mod that uses those, or ones you have made yourself.