Photoshop Pixel Bender and HDR

Brice Vandemoortele

I usually do scripted image manipulation using maya's hardware rendering and cgfx. But in this case I want to generate RGBE/RGBM images to workaround the fact that maya can't load HDR maps (yes I never managed to do this so if you did, pliz help).
So I need an external application and PS CS4's Pixel Bender seemed like the perfect solution, especially after this statement on Adobe's website:

"Supports all bit-depths — The same kernel runs in 8-bit/16-bit/32-bit within the application."
http://labs.adobe.com/technologies/pixelbender/

But in my case as soon as I open a 32bits per channel image, or even create a blank one, the pixel bender menu is deactivated. Give me a big 'WTF?'
Is that a new big marketing lie or am I doing something wrong?

DarthNater

I could have swarn that I. Used HDR images in Maya when I used to use it. Are you sure you can't load them? I don't have maya anymore so I can't check for you (sorry). I'm sure a maya expert will be around soon

Brice Vandemoortele

This is for realtime use - of course you can use hdr maps for offline rendering - but in my case I want to load it in a cgfx shader.

DarthNater

Ah, yeah I used to render with them. That's back when I could make a sphere look awesome as shit by loading an HDRI map and hitting render

Anyway, maybe someone has written a shader for it? There has to be one out there somewhere....

chronic

I managed to load 16bit and 32bit float dds files in an HLSL shader, I dont know the exact differences in support between the hlsl and cgfx compilers.
I loaded the hdr in photoshop and saved out the .dds as 32.32.32.32 ABGR using Nvidias dds tool.
Maya complains on loading the image into a file node, and there is no file node swatch preview but the info seems to be retained and interpreted properly by the hlsl shader.
I have the ddsFloatReader.mll plugin loaded in maya's plug-in manager.
photoshop doesnt seem to have any problem opening the .dds back again with all the dynamic range retained - also using the Nvidia dds tool.

Brice Vandemoortele

Yes I'm also able to load dds using HLSL, unfortunately it is like 5 time slower than cgfx, making it unusable for my client's needs. I can't preprocess the maps using hlsl either since i can't hardware render it like i would with cgfx.