vrimg2exr render element embedded alpha?

[mj3d062]

Hello,

Is it possible to export an .exr render element image with an embedded alpha from a .vrimg file using vrimg2exr.exe? I want each exported render element image to have its own alpha just like images generated from the V-Ray Frame Buffer/Split Render Channels option with "Save alpha" checked.

Using the "alpha" element to mask out the render channels in CS3 is producing fringing around objects. The only way I've been able to get a clean composite with no fringing is to use the V-Ray Frame Buffer/Split Render Channels/Save Alpha option but due to memory limitations I am not able render large print resolution images this way. I have to render to the .vrimg format instead.....

Thanks

[vlado]

Hm, I remember people specifically asking for the alpha to be removed...

Best regards,
Vlado

[Shimakaze]

hehe yup.
Anyway I believe if you use ProEXR and export as a single exr file with all render elements, you can have it apply the alpha to all layers when opening the file. Doing that should take premultiplying into account as well and should be correct
In fact if I remember correctly it should have that behaviour by default. I have a custom build though so I'm not 100% certain.
Oh btw, most render elements aren't supposed to be masked out. you should use blend modes to composite them instead.

[mj3d062]

ProEXR solves the problem, thanks Shimakaze. It does it by default like you thought. I need the lighting element masked because I am compositing over a photograph and this is the only way I've been able to get a composite without a dark fringe in Photoshop CS3. I add or multiply other elements (GI, Reflect, Shadow, etc.) without a mask.

Vlado, would it be fairly easy to add a flag for alpha in vrimg2exr.exe?

Thanks again for the help.

[victor.nsy]

.....
Oh btw, most render elements aren't supposed to be masked out. you should use blend modes to composite them instead.

Any specific steps do you apply your blend mode to make it right?

[Shimakaze]

I posted a list of the most common ones a while ago.
http://www.chaosgroup.com/forums/vbu...3&postcount=15
It's pretty easy once you understand the concept.

Oh if you're gonna do this, you should use LWF as well or you might not get the result you were expecting.

[mj3d062]

Hm, I remember people specifically asking for the alpha to be removed...

Best regards,
Vlado

Do you have an old build of vrimg2exr with alpha?

[vlado]

Nope; I could probably build one, but it will be easier for me to add the option...

Best regards,
Vlado

[MuratCetin]

Hm, I remember people specifically asking for the alpha to be removed...

Best regards,
Vlado

Hi Vlado, is it possible to have "alpha channel" added back to vrimg2exr as an option at least? (after 11 years ).
Or is it implemented already? Right now, we use VrayVFB and maxscript to load a .vrimg, iterate through all of its channels and save them as single-file EXRs with RGBA. )
Thanks.