| kbonin |  posted: Tue Apr 18, 2006 4:00 pm | |
Member since:
2005-08-07
Posts:
7
| For those of us playing around with .dds textures, it would be nice to be able to export .dds textures directly in their original DXT* modes, complete with alpha channals and mip levels intact. Since they're already compressed, the only way (I can see) to export and return to .dds format is to export the texture and alpha channels to a lossless format, then rebuild the DDS and MIP levels, but that means recompressing a decompressed texture, which adds error. |
| pinhead | posted: Tue Apr 18, 2006 5:12 pm | |
Member since:
2005-03-06
From:
Brazil
Posts:
237
| You can export the image as BMP. The alpha channel will be stored together and you can
edit it looking at channels in your image edit program.
Just make sure that you change the name of the image (romove the .png extension in the name created by the exporter) and change the drop down to use BMP instead of PNG and will be saved as BMP fine.
i use photoshop DDS Authoring plugin, so i can save it as DDS directly from there and import the DDS in SimPE. |
| kbonin | posted: Tue Apr 18, 2006 7:52 pm | |
Member since:
2005-08-07
Posts:
7
| I know I can rebuild a .dds by exporting and running back through a .dds builder, but that results in a transcoding pass on the artwork, which introduces further compression artifacts. I'd like to be able to save the .dds directly so I don't have to add that error... |
| quaxi | posted: Tue Apr 18, 2006 8:15 pm | |
Member since:
2006-04-28
Posts:
3154
| When you export a .dds direct, change it and save it again, you will also get the additional compression artifacts, like you would get them saving to bmp (which is a loseless compression). |
| jaxad0127 | posted: Tue Apr 18, 2006 10:33 pm | |
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2005-10-01
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Near my laptop
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| What compression?  |
| kbonin | posted: Tue Apr 18, 2006 10:52 pm | |
Member since:
2005-08-07
Posts:
7
| The .dds file format is compressed. If you export the color and/or alpha channels in a losless format they are decompressed. When you use a .dds builder to recreate a .dds file, they will be recompressed at that time with whatever quantization and compression modes you have selected.
This invariably introduces errors that you would not see if you had saved the .dds resource from the .package file directly, since those channels will now have have gone through two passes of quantization and compression. Even with the same mode selection, you will add some error. |
| Emily | posted: Tue Apr 18, 2006 11:44 pm | |
Member since:
2006-04-17
Posts:
361
| kbonin wrote: The .dds file format is compressed. If you export the color and/or alpha channels in a losless format they are decompressed. When you use a .dds builder to recreate a .dds file, they will be recompressed at that time with whatever quantization and compression modes you have selected.
This invariably introduces errors that you would not see if you had saved the .dds resource from the .package file directly, since those channels will now have have gone through two passes of quantization and compression. Even with the same mode selection, you will add some error. I think not. :) this is what happens when you save the Resource to .bmp: - Decompress dds
- Export to .bmp
- Change the image in Photoshop or whatever
- save as .bmp
- use build dxt (or any other way to create the .dds form the .bmp) to create the .dds for the changed Image. This step forces a recompress.
now the same thing with saving directly to .dds: - Export to .dds
- Change the image in Photoshop or whatever (this will decompress the .dds internally)
- save as .dds. This step will force a recompression.
- import the .dds back.
No matter which format you use to export, the .dds will get recompressed only once.
|
| pinhead | posted: Wed Apr 19, 2006 1:08 am | |
Member since:
2005-03-06
From:
Brazil
Posts:
237
| what do you mean about errors? losing quality or something?
i don't see any problems exporting the image as BMP and saving as DDS later. everything looks just fine when i do that.
i just notice that sometimes i have to expand the edge area in the color that i created to not got mixed colors when compressed. But it's caused by the DDS compression (if you look at maxis textures you will see some expanded color squares around the edges also, and maybe is created like this to avoid this problem).
so, looks normal. |
| kbonin | posted: Wed Apr 19, 2006 3:46 am | |
Member since:
2005-08-07
Posts:
7
| Erm, so what if I would like the .dds to get recompressed zero times?  |
| Emily | posted: Wed Apr 19, 2006 3:54 am | |
Member since:
2006-04-17
Posts:
361
| The only way is to not edit the image . But I guess that is not an option  If the quality is really important for you (and you do not care about the filesize), you can allways change the format of the TXTR to RAW24 (or RAW32 if you need alpha). That way, there won't be a compression, and the texture data is writen 1:1. But the cost is a way bigger size of the .package. Just as a reminder (in case you do not know): You do use " Build DXT" when importing the texture back to SimPE, and you do not click anything else besides Commit on the TXTR Plugin after that. |
