dds compression

Scruples

Either I am doing something wrong or nvidia and ati are using inferior DXT1-DXT5 compression in comparison to 'DDS converter 2.1's compression.
And I am kind of miffed since I have been using nvidia's since forever.

saved as maximum quality jpeg.

ivars

What compression are you using? DXT1 in all images? Are the file-sizes the same?

Bal

Can't really see the differences so well on the right side, even though it's not surprising that there would be some variations with different compressors. But is the quality really better with DDS Converter? Could you take some shots of the different .dds files applied to a model with a basic light setup?
And yeah, these are all DXT1 right? No funky swapping like DXT5NM or such.

Scruples

All of them are DXT5 with interpolated alpha, no funky swapping of channels, and all the same file size.
DXT 1 and DXT 5 yield similar results if not exactly the same, I will post some pictures of the model with it on, not tonight though.

EDIT:

Ok, I am totally wrong (yay)
Even though the nvidia texture has the largest difference between the original in Photoshop...it still looks the best in the Maya viewport, which is what matters...although I still dont understand why

I'll post pictures soon



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Eric Chadwick

Yep, you're going to find differences between DXT compressors, simply because they can be weighted in different ways. Even within a single tool sometimes you can specify different ways to weight the colors, depending on what you want (speed vs. accuracy, etc.).

You can tell the NV Texture Tools compressor to take normal mapping into account and I think it is supposed to compress with less artifacts.

BTW, DDS is just a container, you can use it to store uncompressed or compressed, at various bit depths (8bit, 16bit, etc.). DXT is a specific compression method, often stored within a DDS file (DXT is used by other file formats too, like Nintendo's TPL).

Some info here...
http://wiki.polycount.com/DDS