norx85 Posted November 25, 2011 Share Posted November 25, 2011 Hi guys,I done a png texture and then i converted it into dds format with a dxt5 compression using dds converter 2. The problem is that the texture on the game became blocky. I've tryed to use other compressions but the file became too large or the quality decreased significantly.How can i prevent this? What kind of compression is the best for making an hi quality texture without produce too large files?I think that posting settings and the results will help. Probably i'm not the only with this problem so i want to make in this thread a list of combinations in order to help who need Link to comment Share on other sites More sharing options...
Ghogiel Posted November 25, 2011 Share Posted November 25, 2011 (edited) compressed formats to use: DXT1 for no alpha. DXT5 for alpha. Some people say DXT3, but they most likely have no idea what is getting stored in their alpha channel, Especially with alpha blend transparency. DXT3 only stores 16 shades of greyscale, if your alpha has in any way more greys than that or you want some sort of anti aliasing and softer blend when transpaerncy, Or just as much controll as to what ends up in your alpha, then use DXT5 888 RGB 8888 RGBA< full 8bit channels. double file size, but no visible artifacts. Useful for normal maps which compress very badly and are prone to show those compression artefacts in game because they modify the direction of the light bounces on a per pixel basis, the artefacts can look larger than pixel sized , when the map is compressed it samples adjacent pixels, And strips color info out of the channels, making it blocky, sometimes more blocky than the size of the pixels of a smaller map.. One trick I often use is to compress the color map, and use a half res 8888 for the normal maps and specular. net result is less blocky in game for zero extra texture size. IF you are using a hard surface normal map bake, this isn't always totally practical or needed, the thin UV islands will sometimes cry out for the extra res, and if the UV is laid out as straightish as poss then you'll get less aliasing. Works a treat on organics and most things for that matter. It's a trade off. Just try it and see for yourself. Edited November 25, 2011 by Ghogiel Link to comment Share on other sites More sharing options...
DeadxPixels Posted November 25, 2011 Share Posted November 25, 2011 There is the problem of mipmaps though. Whatever they are,, they affect the result. Link to comment Share on other sites More sharing options...
norx85 Posted November 25, 2011 Author Share Posted November 25, 2011 So correct me if I'm saying something wrong: the problem on blocky textures are bad compressions on normal maps. I'll try it as soon as possible (now i can't, i'm in the office :tongue: ) Link to comment Share on other sites More sharing options...
Ghogiel Posted November 25, 2011 Share Posted November 25, 2011 There is the problem of mipmaps though. Whatever they are,, they affect the result.What problem with mip maps? Use them. You can get super funky and do fade if it is a landscape texture and sharpening ect, not to mention the many types of filters used to create them. So correct me if I'm saying something wrong: the problem on blocky textures are bad compressions on normal maps. I'll try it as soon as possible (now i can't, i'm in the office :tongue: )Most prominently, yes. that is the one thing that has the most impact. The color maps themselves suffer much less because most of the times the things are quite noisy and full various color info anyway, so compression is hidden better, plus they do not modify lighting direction changes. On normal maps it stores a color that modifies the normal direction, and light reflects off it in a blocky fashion, being counter productive to the actual job of normal maps, in that they can correctly smooth and add detail to the surface of a mesh by making changes to the direction light reflects off it. Link to comment Share on other sites More sharing options...
darthsloth74 Posted November 25, 2011 Share Posted November 25, 2011 I was just wondering since I do a fair bit of texture work why colours such as black and in some cases blue, seem to have more apparent visible artifacts when compressing to DXT1 . Dark areas can sometimes look brown or even purple in some cases, is there a specific solution to this? Since this problem has always bugged me. Link to comment Share on other sites More sharing options...
Ghogiel Posted November 25, 2011 Share Posted November 25, 2011 I was just wondering since I do a fair bit of texture work why colours such as black and in some cases blue, seem to have more apparent visible artifacts when compressing to DXT1 . Dark areas can sometimes look brown or even purple in some cases, is there a specific solution to this? Since this problem has always bugged me.good question. I suppose it's to do with how the dxt lookup table works. And no... those darks often look like ass no matter what you do. It's part of the trade off when compressing. But if anyone has something else to add to this topic I would be appreciative. Link to comment Share on other sites More sharing options...
darthsloth74 Posted November 25, 2011 Share Posted November 25, 2011 Glad to know its part of the compression. Ever since I did stuff for Fallout 3 I always thought it was some mistake I was making. Thanks for the informative answer. Link to comment Share on other sites More sharing options...
DeadxPixels Posted November 25, 2011 Share Posted November 25, 2011 Mipmaps on armor anyway. I've messed up a texture because I let Photoshop generate it's own mipmaps for the armor piece I was changing when I saved it. Link to comment Share on other sites More sharing options...
throttlekitty Posted November 26, 2011 Share Posted November 26, 2011 Are you opening the image with mipmaps enabled? Link to comment Share on other sites More sharing options...
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