What Are the Conditions for Preserving Alpha?
I can open a 16-bit PSD file, and a 16-bit TIFF file (LZW compression) into separate ShaderMap 2 sessions without issue; however, the alpha channel in both instances is ignored, going solid white.
Alpha channels are preserved when opening 24-bit PNG files.
Am I missing something? Are there any conditions peculiar to the TIFFs and PSDs in order to preserve the alpha channel in SM v2.0.72?
Alpha channels are preserved when opening 24-bit PNG files.
Am I missing something? Are there any conditions peculiar to the TIFFs and PSDs in order to preserve the alpha channel in SM v2.0.72?
Comments
Alpha goes white:
Displacement map produced from color source from 16-bit .psd
Alpha goes black:
Displacement map produced from color source from 16-bit .tif
Also notice how different the Displacement maps look even though the same image has been used in Photoshop to create the .psd and .tif files.
Alpha works:
Displacement map produced from color source from 24-bit .png
Here again, notice how different the Displacement maps look even though the same image has been used in Photoshop to create these files.
There is a problem with the PSD and TIFF loaders used by the image library. It is not working for the alpha channel of 16 bit files.
The image loading problem is happening in an external image loading library called DevIL http://openil.sourceforge.net/
I may need to write my own loader or fix and recompile the DevIL library myself to get this to work. It is on the bug list.
Neither the DevIL Reference Guide nor the Manual (1.1.5) addresses 16-bit related issues. I guess the devil is in the DevIL details. Sorry I'm not a programmer, but I can offer to help by testing / experimenting.
Have you contacted Denton Wood ? Maybe a collaborative approach would be worth considering.. duno, but I'm not holding my breath. Not much hope of that idea offered here: http://sourceforge.net/projects/openil/support and things look stuck at 1.7.8 from March 2009. His last words "DevIL is not dead..." were almost 4 years ago and the thread on DevIL 2.0 likewise has grown stale.
Who knows, maybe there are other developers faced with this issue?
My approach will be to build my own loaders. It isn't that difficult and will allow me to add support for 32 bit / channel PSD at the same time. I have plenty of resources to do this on my own, it just takes time and is not the focus of my work at the moment.
DevIL is probably not dead. Denton pops up from time-to-time puts a lot of work in then disappears again.