To mip or not to mip....that is the question

[matchbox2022]

Heyah Vice or others,

Had a question involving in-game textures, was heading to bed and couldn't decide if when modding textures for the starX-x files if I should be using mipmaps in dds format (I figure DX5 dds is the best way to go for memory and gpu decompression).
I have no idea if the "skybox" itself in game would benefit from mipmapped textures or if it just sits around taking up download space.

I figured ...no they wouldn't be used...but then I thought what about for reflections off the water and dynamic cubemapping, or even the new shaders?...

So I was wondering if you knew for sure about the above as it's either a waste of download size or it's pretty helpful for fps.

[Vice]

By default, the textures that are in the game (DDS DXT5) include mipmaps. So including them in custom textures won't add any further memory overhead to the game from what it already utilizes (if you keep the resolutions the same). Including mipmaps probably wouldn't help too much for performance (possibly most notable on low end systems, if any significant difference). By the same token any additional download space would probably be fairly minimal due to the limited number of files and compression provided by the DDS format. Reflection mappings tend to render softer quality captures of the images anyway, kind of like they are mipmapped already. Where mipmaps tend to help the most is in image quality at narrow angles on their direct surfaces, reducing pixel popping and shimmering. But since the background starfield and nebula details are generally always facing the camera at fixed angles, this isn't much of an issue overall. So for just these image sets, I'd say it's optional if you want to include them or not. The deciding factor for you might come down to whether you notice any difference in performance on your system as that would likely be the only significant potential benefit.

[matchbox2022]

Thx Vice

Using DXT5 I was noticing that some textures with high contrast or subtle color changes were getting pretty artifacty, even though it makes the size a lot smaller that wasn't worth it to me so I haven't been using it generally. With mipmaps the file size increases a surprising amount when I'm already at 16MB a picture. I decided to basically include two versions if people notice slowdowns.

[Marvin]

I decided to basically include two versions if people notice slowdowns.

Did you test using the default settings or the ultra high settings?

[Vice]

Thx Vice

Using DXT5 I was noticing that some textures with high contrast or subtle color changes were getting pretty artifacty, even though it makes the size a lot smaller that wasn't worth it to me so I haven't been using it generally. With mipmaps the file size increases a surprising amount when I'm already at 16MB a picture. I decided to basically include two versions if people notice slowdowns.

Yes, compression can produce artifacts and it varies by what colors/patterns are involved. You'll never want to use DDS for normal maps since the artifacts can effect light reflection response in unwanted ways. For fine tuning other texture maps though, adjusting the color bias settings in whatever DDS editor you are using can help reduce or even largely eliminate artifacts. For example, sometimes I have to set color weighting to more blue to prevent artifacts from appearing in certain nebula cloud backdrops.

[matchbox2022]

I decided to basically include two versions if people notice slowdowns.

Did you test using the default settings or the ultra high settings?

Wouldn't make too big a difference for me....though I have an older video card my bus width is pretty high even for today.
So personally I got few slowdowns, but I might try lowering my memory clocks and seeing what happens between the two. I just included compressed textures for good measure.
The DX5 textures are noticeably worse to me so I used the ultras / lossless.
Not quite finished them all, might reupload after work.

[Vice]

Artifacts can be annoying. I've spent many hours tuning and tweaking the color weighting and designs for the in-game DDS textures to minimize/remove artifacts and it's not an easy task.