how to treat all the other layers/alpha channels

I find plenty of tutorials and references here to creating multiple layers/alpha channels when creating a clothing item.. My problem is that after doing that I'm losing everything on all but the first layer and alpha after I've saved to .tga and import it.

I know .tga only supports one alpha channel so what is done with all the other layers/channels --- for example those that might be the highlighting or wrinkles, trim etc on a shirt.

I'm using Paint Shop Pro but I think if anyone has an explanation of what they do in their own program I could translate that to PSP. I think ...

It doesn't make any difference whether you are using Photoshop, PSP, GIMP, whatever .... When you save as TGA and upload, any active (i.e. visible) layers are preserved as a single flattened image. You don't need to do anything to flatten it yourself beforehand. Your TGA, PNG, JPG image is automatically flattened for you as it's saved, and all the information on active layers will be there. Besides, the image in SL is a JPG2000 file, which knows nothing about layers. As far as the alpha channel is concerned .... yes, you can only have ONE alpha channel, so be sure to check that before you save the file and upload it.

Save your multi-layered/multi-channeled work as a PSD before you output to TGA. That way, all your layers and channels will be there for your use whenever you need to make alterations to the image.

Flat formats like TGA are only for final output, not for archival, and not for working.


As Rolig said, when you output to TGA (or to any other layerless format), all your visible layers are automatically flattened. This is why the software always warns you that the TGA will be saved as a copy, not as an original. It's to ensure that your layered work is not destroyed.

If your working document has more channels than the output format supports, the way they end up composited will depend on what program you're using. In most cases, you end up with an all white alpha channel. To avoid problems, always make sure you have the exact number of channels you need, no more, no less, before you do your final output.

If you want to preserve multiple versions of alphas, a good way to do that is to make a layer group, keep its visibility turned off, and put all your extra alphas in it, as layers. Then when you want to use one, simply copy it to a channel.

there is one litle snag. When a tga file is 'flattend' some proggies (eg GIMP) will pop an option to use 2 different types of compression. This should not be chosen. -eg de-check both.
BR.