Vray raw output not compressed?

[thn]

Hello
I much prefer to use the "Vray raw image file" outputoption for multichannel exr, for a couple of reasons, but it strikes me that the file size is much larger than when I use the standard 3DS Max file save option.

See:


The two files saved with Vray raw Image output are much larger than the one from the Common tab output option in Max. Largest is the 32bit output of course.
With Vray there's no option to choose which compression method to use for each layer.

I miss the OpenEXR options:


These are available for separate render channels output but not for raw image file output.

Regards,
Thomas

[vlado]

We have not been able to reproduce this. If the 3ds Max output is set to save all render elements, the sizes are comparable.

In your example, the 3ds Max output only saves the RGBA data, so of course it's smaller.

Beat regards,
Vlado

[thn]

The openexr dialogue I show is only an example. The files I've saved are identical, they each have three channels. I checked in Nuke that they all had the channels.

[vlado]

Then it would be best to give us some way to reproduce the issue - either a scene or more specific reproduction steps.

Best regards,
Vlado

[thn]

Hi Vlado
I've attached the scene and two different exr files, saved with standard max output and Vray raw. They both have 3 elements.
teapot-size.zip

/Thomas

[instinct]

There's two differences in the exrs:

- The DEPTH is kept at 32bit in the vray one (which is as intended), due to the way DEPTH is created (using samplerinfo) it uses 4 channels which accounts for 25% of the channels
- The compression is zip multiscanline which compresses quite a bit better than ZIPS but is also slower to read in nuke (depending on the use case of course). You can use multi scanline compression using the optionRE renderelement

Cheers,
Thorsten

[thn]

Thanks for that explanation! It is the samplerinfo element that does it. Without it the file sizes are almost identical.
In Nuke I can't tell any difference between the elements, no banding or anything on that saved with max output option, but it may be there at a mathematical level.

Cheers,
Thomas

[instinct]

Thanks for that explanation! It is the samplerinfo element that does it. Without it the file sizes are almost identical.
In Nuke I can't tell any difference between the elements, no banding or anything on that saved with max output option, but it may be there at a mathematical level.

Cheers,
Thomas

Depending on the settings and what you plan to do with depth it does make a big difference. Only for position and depth passes from our tests though. I would still suggest using VRayZDepth instead to save additional channels.