Hi Aldo, I looked into your composition and realized that your shader uses a sampler2D input for the Map. That will convert the texture for sure, because the input isn't matching a square texture. So your Map texture will get made square before going into the shader. I don't know what happens to the bit depth thought. Use a sampler2DRect for all your texture inputs.
Actually I tested using the sampler2DRect and the result looks the same. Don't know why it converts to 8-bit. A workaround could be to bring the precision you needed into the 8bit range: Use a core image patch to remove the xy-coordinates from the Map-Datat and only have the pixel offset stored here. I don't know what your precision depth looks like, but I think I could be enough to store -10 to 10 pixels shifts in 256 steps to get the result correctly. And if you are using RG for X and BA for y direction you will get back your 16 bit precision anyways :-) Writing all this it it could be working if you split the UV-data, which is stored in RG currently, into U = R *256 + G ; and V = B * 256 + A; then you have a new Map texture wiht 8 bit precision in RGBA that goes into your shader. Just an idea for a workaround thought. best, Achim Breidenbach Boinx Software On 13.01.2012, at 22:02, Aldo Hoeben wrote: > > > How do I stop the GLSL Shader patch creating an 8 bit texture from my 16 > > bit image? > > See the image below. RGBA16 image becomes BGRA8 texture. The same happens > when I save the image as a 32 bit float image. Is this just happening on my > hardware (Intel HD3000), or is there a way to convince QC to create a 16bit > or float texture from my image? > > (yeah, at some point my composition crashed) > > <ghidbdfb.jpg> > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Quartzcomposer-dev mailing list (Quartzcomposer-dev@lists.apple.com) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/quartzcomposer-dev/achim%40boinx.com > > This email sent to ac...@boinx.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Quartzcomposer-dev mailing list (Quartzcomposer-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
