This is incorrect. Mip maps are necessary for almost every texture. Removing mipmaps from normal maps would have a horrible effect on the clarity of the image. Not using mipmaps would result in a "shimmering" effect as seen on the image here: [img][src="http://www.shinvision.com/wp-content/uploads/2009/06/mipmapping-egz.png"]http://www.shinvisio...mapping-egz.png[/url][/img]

If mipmaps are removed, the pixels on the left example would be constantly moving. This would be very noticeable on normal maps; from what I've seen normal maps included in most texture packs are done rather badly and are incredibly noisy.

I have posted a link to this thread on Polycount forums (it's a forum dedicated to video game art that is populated with game industry professionals), hopefully some of them will contribute to this thread. I appreciate the idea of making texture packs because I do believe that they suffer from being low resolution, but at the same time a vast majority of texture packs could look a lot better and could be done more efficiently.


Some random thoughts:

Unfortunately, creating texture replacers for objects that had their normal maps baked from highpoly models is pretty much pointless. Their diffuse textures can be tweaked, but modyfing their normal maps in Photoshop will often produce technically incorrect results. Objects like that rely on normal maps NOT to add surface detail, but to define the shading of a lowpoly object and bring it closer to its highpoly version. Upscaling normal maps and overlaying noisy detail on top of it can make it appear slightly sharper, but in most cases it will produce worse results than rendering the normal map at a higher resolution. Here's a massive article about normal mapping in current generation video games: http://wiki.polycount.com/NormalMapThe article also has links to tutorials that deal with the subject in more detail.


I will try to contribute to this thread every now and then. Compared to some of my peers, I may not have a lot of professional games industry, but looking at texture packs posted here I often spot plenty of simple mistakes that could be fixed pretty easily and elevate the quality of textures to a higher level.


Edit:

Here's a link that discusses DXT formats. http://wiki.polycount.com/DXT
There should be no difference in the colour reproduction between DXT1 and DXT5. The only major difference between the two is that the latter supports 8-bit alpha, at the cost of being twice the size of a DXT1 texture.

My apologies. Seems i was basing my assumption on PS not asking me if i wanted to load them as not having them. I changed my settings so the dialog appeared regardless and loading mip maps for normals does indeed show that vanilla normals have mip maps. My mistake.

Sorry if I sounded harsh; these things can be confusing so there's no need to apologise. I'm hoping to contribute what I know so its easier for you guys to make these things. I could use a good texture pack

How can a DXTC1 format saved with a 4 BPP format have remotely the same color pallette of a DXTC 3/5 with 8 BBPS. That's one of the MAJOR reasons the file size is considerably larger. Aside from there being an Extra channel being Alpha which is 8bit

8bit RGBA is essentially 24+8bit (32bit) texture... where as 4bit RGB is 12bit without alpha texture, 13bit if 1bit alpha is included.

I'm not expert at all..... but trying to understand the formats and how the differences are beyond just the very basic and exluded details...

So obviously there needs to be more information provided.

I don't think the 4bit and 8bit settings determine per pixel depth but rather over all image depth. When I load a dxt1 dds into PS and look at it's mode it still says 8bit rgb(which is the per pixel color depth). For a 4096 image to have full overall image 8bit depth, every single one of the nearly 16.8 million pixels would have to be a different color. I doubt too many textures are sporting more than a few hundred thousand colors.

I could be wrong but that seems like the way it is.

it's not if a texture is able to use all 16.8 million colors.. it's if the saved texture makes use of any one of those colors that isn't available in the lower bit color pallette.

For example.. to simplify it, lets use 256 color pallette (8bit overal color) vs 65355 color pallette (16 bit overal color)

IF you save a 16bit color image in a 8bit color format, whatever colors don't match the 8bit pallette, is downsampled to the nearest color that does fit the 256 color pallette.

I do not beleive DXTC formats have a dynamic method of saving colors where the exact 32bit color pallette is maintained. Frankly i'm not aware of any such format that is capable of this. Although i think it would be ingenius for someone to make one allow for 32bit pallettes to be compressed into lets say a 4 bit pallette or 6 bit or 12 bit with ZERO color/shade impact. Would save a PILE for computational/size requirements.

Very Good post I hope it gets sticked somewhere togehter as some other posts about performance ...

I just did a test and textures saved using all of the following settings...

DXTC1 4bpp | no alpha
DXTC1 4bpp | 1 bit alpha
DXTC3 8bpp | explicit alpha
DXTC5 8bpp | interpolated alpha

...each have 32bpp color depth.

I think this is what makes the DDS format so viable. A DXTC1 compresses the image size down to 4 bpp size but retains the full 32bpp color pallet.

Great post with some essential info and very good advices there, Mart!

I have some reservations about switching every texture that doesn't need a transparacy to DTX 1 though, as every form of DTX serves a different purpose. On that note, anyone know if DTX1 is more similar to DTX3 or DTX5? If I do remember correctly DTX5 handles transitions more smoothly, while DTX3 is more precise. It might not be a world of a difference, but I'd still like my textures to come out in the best way they can.

Here is a small article that explains it:

http://www.fsdeveloper.com/wiki/index.php?title=DXT_compression_explained

There is a difference between DXT1 and DXT3 even in the RGB channel, but it is so tiny that it's not worth it - I'm not even sure it's better, just different. Save your texture in both formats and compare - you will see that a few pixels are different, but both are compressed and DXT3 doesn't look better than DXT1. If you want to get the best result and if you don't care about filesize save as 5.5.5 or even 8.8.8 (you will see quite a noticeable difference when you compare to DXT if you save in these formats). That is not recommended due to the much larger file size though. Usually that is only useful for normal maps that get a lot of artifacts when saved in DXT format - sometimes it's better to downsize the normal map and save uncompressed (or with less compression) instead of getting a lot of ugly artifacts. Probably you've seen the 'no more blocky faces' mod, which is quite popular. The artifacts on the face normals were caused by DXT compression, which happens quite often on normal maps. Bethesda still saves all normal maps compressed, no matter what. For diffuse maps I don't see the point as smaller texture means less detail and more blurriness while same size uncompressed means a huge file size. Plus DXT isn't that obvious when used for diffuse maps.

Ah, thanks for the info, Phitt. That article explains it very well, adding it to my bookmarks for reference.

http://cs.elderscrolls.com/index.php/Choose_the_right_DXTC_compression_algorithm
http://en.wikipedia.org/wiki/S3_Texture_Compression
This may help clear things up a bit.
edit: kasdhfkjsdhfh i'm not awake enough to deal with whatever is going on with the links right now.

I can't count the number of times I have read that article though admittedly it's been a couple years.

So is there a way us end-users can do any of these things on our already installed (and possibly never to be fixed mods)?

• Save textures as DXT1
• Save textures with alphas as DXT3 or DXT5
• Save normalmaps as DXT5

Is there a potentially a script we can run to anolyze every file and compress as necessary?

http://www.gamesas.com/topic/1330264-ddsopt-of-use/

You will have to manually examine your mods once again, compare the original vanilla textures to the modded version and adjusted the modded version has needed once again. That really is only way to do it once again..

But then again I could be wrong ...Thanks Worm..

I have a question about the enchanted item graphical effect that perhaps one of the guru's here could answer. How exactly is it mapped to the weapon or item? I've experimented with changing it, but I'm not happy with the results I've been getting. The alpha channel seems to get plastered all over, in the oddest positions.

This is not true. Oblivion did switch shaders based on the DXT-format and for Oblivion DXT1 means "no alpha", not "1-bit alpha", and it uses the shader which doesn't use the alpha-information. The exception is the UI, there you indeed can use "1-bit alpha", but not for assets used in the game itself. Also, the meaning of "no alpha" changes is you have a color-map or if you have a normal-map. For color-maps the alpha-channel may contain transparency, so neutral alpha is white. For normal-maps the alpha-channel can contain specularity, so neutral alpha is black. For color-maps the alpha-channel may also contain a heightfield, so neutral alpha is whichever solid grey (it's a difference-map, no differences, no effect, only waste of GPU-cycles).
If this still holds for Skyrim we have to find out. Anyway, that's what DDSopt is about, don't memorize this stuff, let a tool do it.

Thanks for the link to that program Martigen, I just saved over 100mb of space on my harddrive by compressing textures that were saved in RAW or 8.8.8.8 formats when they had no need to be.

Not to mention the performance increases, even though I've got a beast of a machine and haven't noticed the problems yet, why invite them?

In Oblivion we had many assets that used DXT1a for 1bit alpha, and it worked fine. Is this to say that behind the scenes the format was somehow promoted to another?
And I disagree, I think it's useful to know these things, so assets can be created properly at the start, rather than going through a compression routine a second time.

Aha! this explains why the transparency maps for my rain drops wernt displaying properly.

I'm gonna play Johnny One-note here for a minute. I've been trying to "fix" a mod that seems to work for almost everybody else and does nothing for me. I don't know if it's something unique to my install (which I've re-done) or machine, but I tried to open the DDS files with The Compressonator and could not open them. If I try a batch compress it skips them, saying it can't decompress them.

The DDS files are quite small, 9k in size, and when I open them in Nifskope I can see a very small texture map. It's referenced by a mesh file and stored in a custom directory under the Textures directory.

The mod is the "Glowing Ore Veins 300" mod at http://www.skyrimnexus.com/downloads/file.php?id=193

It doesn't really need compression for size, but I've tried just about everything else to get it to work.

I tried replacing one of the textures with a candlelight texture from another pack (that opens in the Compressonator), to no effect, so it may not be the textures that are the problem. The other texture works as a replacer for the texture it was intended for. I don't know if the DDS file contains internal identification or is just a texture so that may have been a silly attempt.

If anyone has any obvious ideas or if you're just curious about an oddity, I'd appreciate the help. Otherwise, carry on as normal. Thanks.

PS it's a cubemap, which is apparently different in significant ways. I am at the wrong spot on the learning curve here.

PPS Not trying to diagnose the issue here, just whether the DDS files are an issue.

SIlly dupe, deleted.

can i "resave" the texture mods with microsoft paint? i know absolutetly nothing about textures or meshes so i would like to do this myself if its fairly straightforward and simple. otherwise its not a big deal since i have a 3GB card.

Thanks for this thread. It has helped me better understand the various DDS formats.