Render elements missing using region/crop render.

[Wingman3d]

I'm rendering a huge animation, its 5120x720.
But it only has animation in some small parts of the image, so i want to render that part with region render, or crop under "area to render", so i can composite the animated part later.
I also use some render elements, most important a lot of multimattes.

I'm rendering to .exr from the normal max render output.

When i render like this with the max frame buffer the render elements are saved as separate exr's, and not included in one file as i want.(this generates a lot of files when i have many elements)
I have also had some problems with some pc's in my render farm who hasn't saved out the elements at all.

And when i render with the Vray frame buffer active, it doesn't include the render elements at all, only the RGB.

Am i missing something here, or is this a flaw?

[Wingman3d]

Been testing a bit more, and it seems like this splitting and saving render elements as separate exr-files only occurs when rendering with backburner over more than one pc.

[Wingman3d]

ok,
so now i'm rendering out an animation to exr from max's ordinary render output save file.
No region type render, just normal 1920x1080.
The pc i'm working on and using as a backburner manager renders out fine to 1 exr per frame, and then i use ProExr eXtractor to 'unpack' it in After Effects.
But those frames that has been rendered on other pc's in my farm save one exr for each render element in addition to the render itself.
That means a get a list of renders like this mainRender000.exr - mainRender100.exr, where only some of them actually contain the render elements.

And then i get a bunch of inbetween separate exr's with the render elements from those frames rendered on the nodes.
This makes it impossible to composite.

What am i missing here? This must be some kind of bug?
Is there something i should do differently?
Change global Compression or something under the OpenEXR configuration?
I'm using Store image as scanline and zip compression per scanline band. (I've heard this is the best way to get fastest response when working on it in AE)

I'm using v1.50 SP5 by the way.
And i've installed the 3ds max connection extension on all pc's.

[vlado]

It might be better to render to a .vrimg file, and then use vrimg2exr to convert to the OpenEXR files.

Best regards,
Vlado

[Wingman3d]

ok, i'll have a look at .vrimg.
thanks for the reply.

Could you please also tell me why you cant render easily directly to .exr?
Why the whole conversion operation? Why not automate this in the renderer?
Are someone using the vrimg-files? What are the advantages of vrimg?
I get the impression that everyone is using exr.

[Wingman3d]

and more questions:

When working in After Effects; which compression settings do you reccomend when converting?

And do this converter create tiled or scanline exr's? (Scanlines are read fastest in programs like AE right?)

And the filesize of the vrimg is huge!
The frame that when saved to exr is 3MB turns into 300MB when saved to vrimg!
I cant turn on an animation for an overnight render because that will fill up my harddrives in a few minutes...

I can use the Vray Framebuffer and render to .exr instead of vrimg though, and get the smaller size.
But then they save as tiled exr, and i cant get the render elements included when using some kind of render region.

So each technique has disadvantages. Why does it have to be so difficult?

[vlado]

Could you please also tell me why you cant render easily directly to .exr?

In fact this is done for V-Ray 2.0; in V-Ray 1.5, there is a problem with the tiles written by V-Ray mismatching the tiles of the exr file when rendering a region.

Why the whole conversion operation? Why not automate this in the renderer?
Are someone using the vrimg-files? What are the advantages of vrimg?
I get the impression that everyone is using exr.

Indeed people rarely use vrimg files directly, and usually convert it to OpenEXR. vrimg is a native format of V-Ray; it was created before OpenEXR appeared (yep, that long ago . It is a fairly simple format and for this reason quite robust. The standard OpenEXR library has some quirks and occasionally fails to work properly, and unfortunately there is little we can do about that.

Best regards,
Vlado

[Wingman3d]

Do that mean you can save out to scanline exr's in 2.0?
And no problems when rendering animations through backburner, and no problems with region\crop?

[vlado]

I meant that there are no problems to render to tiled OpenEXR files with region/crop renders with the V-Ray VFB (which was not possible before and produced errors).

If you render to stripes then you will still have to use 3ds Max VFB. This should work fine with backburner in recent 3ds Max versions. I'm not sure how it handles region and crop renders when combining the stripes though - this is something that 3ds Max handles internally and we don't have control over that process.

Best regards,
Vlado