How Do I Make Smaller DDS Files in GIMP?

[David Brasher]

I have this giant mod that is so big that it will be hard to upload and download. Much of the problem is all these textures that use up so many megabytes. I live in a small town and my Internet connection is not great, and I am not the only one with this sort of problems.

 

How can I make my textures even smaller when I compress them with 7-Zip which can compress files smaller than WinRar? For an example of my problem, I have this retextured Imp. GIMP turns out a larger file than the original texture file for the imp which I just copied and changed. On some settings it is like twice as big. To work in the game, the texture must be what GIMP refers to as an "RGB-Alpha, 1-Layer." The format that meets these requirements that seems to turn out the smallest files for me is "RGBA4."

 

What GIMP settings or software can I use?

 

What can I do to reduce the file size of my textures?

[Eiries]

If you're not, it's always best to compress .dds files using the BC3/DXT5 format in GIMP. In rare occasions there may be a loss of quality, but usually there's no visible difference.

 

Also, when you're making a 7z, make sure to set the compression ratio to Ultra for best results.

[David Brasher]

I just tried that out at your suggestion: RGBA4, BC3/DXT5.

 

But that makes the creature render as pure featureless black in the CS. Did I do something else wrong?

[ub3rman123]

Normal maps?

[David Brasher]

I have a renamed copy of the vanilla Oblivion normal map. I mostly just changed the color of the Imp using filters. I think I might have touched up a few spots with a brush. The contours are still the same so I did not generate a custom normal map. I pulled off the new RGBA4, BC3/DXT5 texture and put the RGBA4 texture back on and the Imp is not black. (I never touched the normal map all throughout these changes.)

[Eiries]

I've never bothered changing the format before. Try leaving it at default and compression at BC3/DXT5 and see what happens.

[alonsomartinez]

This might work

 

If you open up the IMP and export the UV map as 512 by 512 then rescale your texture to 512

 

by 512 then copy that texture onto the uv it might

 

bring down the file size.I dont think there will be much visual loss.

 

Just tested it out with a sword I textured

 

My original texture was 1024 by 1024 and it was 4 mb

 

I exported the uv from the model in nifskope and rescaled my original texture from 1024 to 512 and pasted it into my new UV and saved it .

 

I applied it in nifscope and I saw no visual loss. Guess what the file size for the new texture was ? 170 kb xD

 

If you need help let me know :D

[David Brasher]

@ Eiries

 

On your suggestion, I tested Default, BC3/DXT5. The imp is black again. It was worth a shot though.

 

@ alonsomartinez

 

I am a dungeon maker and quest coder and don't know much about retexturing and nothing about modeling. What is a UV map? I did a quick Internet search and just kept turning up information on UltraViolet light. I sort of got in over my head. I was called into the project for play-testing and debugging in my area of expertise but have ended up spending a ridiculous amount of time trying to fix up things that the model and texture people fouled up.

[ub3rman123]

The UV map is the map the model uses to figure out what polys go where on the texture.

 

Actually, I don't think you'll need to scale the UV at all. Shrinking the texture will automatically take the UV with it.

[monkmidon]

@ Eiries

 

On your suggestion, I tested Default, BC3/DXT5. The imp is black again. It was worth a shot though.

 

@ alonsomartinez

 

I am a dungeon maker and quest coder and don't know much about retexturing and nothing about modeling. What is a UV map? I did a quick Internet search and just kept turning up information on UltraViolet light. I sort of got in over my head. I was called into the project for play-testing and debugging in my area of expertise but have ended up spending a ridiculous amount of time trying to fix up things that the model and texture people fouled up.

 

Actually, you don't have to mess with the UV map of the mesh, just simply scale down the texture to something like, 256x256, and then make a new normal map of that texture. Doing this should reduce the size by about 4 times.

 

Also, since the imp texture uses transparency, you should use the compression rate of DTX5, and for the normal map, too. And be sure to have checked off "generate mipmaps".