Hey everyone,
no matter what i trz, i cant seem to get vray to save unclamped gbuffers. They all look fine and seem to be full float in the vfb, but no matter if i save them to floating tifs, or to exrs they are always clamped.
I tried playing with “Clamp output” etc…but no luck. Any ideas ?
Note: am trying with 1.5RC2’s Renderelements implementation and try to save using the “Save out seperate GBuffer Channels” in the vray VFB rollout.
Regards,
Thorsten
thorsten, all of the vray render elements have the option to use color mapping (on/off) and the clamp output (if its checked in the render dialogue)
edited version above…
clamp output is off tho…so it shouldnt matter if colormapping is on or off, should it ?
And just tried it, it does indeed not change anything at all. What goes out is clamped. While it is not in the vfb 
Thorsten
Hm,
I tried it for a while now, too. And couldn’t get unclamped exrs. I suspect that this is a bug. Would make the whole renderelement thing less efficient.
Dieter
it does sound like a bug.
Hey dimo, hope you doing ok after your accident? sounded nasty!
working flawless… see the sample scene!
regards,
Michael
no it doesnt.he…there’s still a lot of testing ahead of me, but one thing i seem to be able to confirm and reproduce is, that vray (or the exr BitmapIO) is not able to save out 128bpp EXRs…when it is set to 128bpp it exports clamped to 8it it seems…mighty odd that you get the least imagedepth when setting it to the highest setting 
Thorsten
Yep it does… Works with half and full float exrs, no problems here, overbright data gets saved. Did you try out my sample file? Are you sure you set all options in the openExr dialog correctly? Especially unchecking “Use RealPixel RGB Data”?
Regards, Michael
i am not sure what the “right settings” are…but i think i got pretty much all combinations done…and as long as it’s set to 128bpp it is definately clamped. What max version are u using ? and what EXR plugin version ?
Thorsten
ah i see…as tried your scene at home i didnt notice before…you’re using max8…and the included exr IO plugin in R8 is a diff beast all together. it misses all the colour stuff (wich i turned off btw). So i assume it’s an R7 specific problem…as R8 is not an option yet that doesnt make anything better tho.
Thorsten
any chance we’ll see a fix for that ? Even with the HalfFloat settings it saves out clamped channels in R7 when autosaving elements thru the VrayVFB settings.
That’s pretty sad as it is seems pretty useless this way. Also there’s some comping problems, but i’ll take that to a new thread once i’m finished with this..
Thorsten
i believe vlado had mentioned somewhere in the past that the clamping problem is indeed a max7 problem and not a vray problem
well am just wodnering, as i cant even use max’s built in Elements save feature, only vfb’s own save feature…that should be able to access all the data, no ?
Thorsten
i believe max has a clamping problem. or something like that. so no matter what you try to access in vray max isnt able to give vray what it wants
For the standard 3dsmax EXR exporter, you need to turn OFF the “Use Unclamped RGB data” option.
Best regards,
Vlado
got it off, and that works for the normal saving, and for saving from vfb via the save button, but doesnt seem to work for the “Save seperate GBuffers” Option 
Thorsten
I was playing around with this the othe day, specifically for compositing in combustion 4, and found that exrs don’t work no matter what I tried, as long as the premultiplied alpha was checked in the exr export dialogue in max8.
Once I unchecked this, I got the full range of colours in combustion.
Can anyone confirm this?
confirmed for combustion…premultliplied is not working. But combustion handles exrs somewhat strange… If you have an overbright highlight with a semi-transparent matte (no matter if premultiplied or not), it always turns out grey, although it should be still white (like: highlight = luminance float 3.0, alpha = 0.5-> 0.5x3.0 = 1.5, but in Combustion, it returns 0.5!). Fusion and shake handle exr data correctly, no matter if it is premultiplied or not.