Open EXR file corruption

[jacobhutson]

We are getting a random issue of Open EXR 32bit Float, channels compressed getting corrupted
the RGB channel ends up with dots all over it.
It doesnt happen all the time and we used to think it was one scene but it happening on a few now so we think it might be 7.1
Progress EXR saves are fine, its just the final output

We didnt get this with 7.0
I am wondering if its compression in the EXR corrupting the file, it all looks fine in the frame
we will try saving out uncompressed and see if it doesnt happen

pretty standard network
windows domain, 1gb lan, all nodes are 7.1, all win7 pro

[snakebox]

I have attached an small image of what the RGB channel looks like when it's corrupted upon saving the EXR. 

The render looks normal in frame buffer, and if you save out a tiff from the frame buffer it also works, so it looks like a file corruption when saving the EXR.
Also this doesn't happen on all scenes.. so far I have seen it on 2 scenes out of 15.  It also isn't random, it will happen 100% of the time on certain scenes, and 0% on others.

[jacobhutson]

here is a crop of the exr
the RGB channel is corrupt and mostly missing

it doesnt seem linked to compression as saving uncompressed has the same effect.
it corrupts if manually saving from the frame buffer
saving tif or png works fine
progress saves to exr work fine

[jacobhutson]

it corrupts the RGB content if there is nothing in the scene but a teapot
it corrupts the frame if erase frame buffer is set

progress render and last render are fine
so it looks like something in the scene goes bang and it cant save EXRs right
not every scene is like this, they work fine and at some point break, and are broken from then on

I have attached a scene file xrefs off, no maps etc so you can see if there is something wrong with the file setup

[jacobhutson]

this is happening with increasing frequency, to the point we cant trust an exr output
progress saves work which is odd (is this a vfb dump)

Some files work some dont so we can only presume its a corrupt file, ill try importing a busted scene into a new max file

[Ondra]

The scene you provided works fine here. Since the saving is handled by 3ds max, not Corona, the problem is probably somewhere in Corona. Do you encounter similar issues also with other renderers?

[Ondra]

Hi,
any progress here? If you cannot provide more info, I will have to close this report.