Is it possible to have lightgroups AOV merged in different .exr ?

[sbauCZF28]

Hi,

We are using lightgroups AOV for comp (in nuke) but as we sort diffuse, specular, sheen, sss, transmission (all direct + indirect) the number of layers makes it very heavy for our .exr.
A solution would be to have a single exr per lightgroup, merging all the aovs of the lightgroups. The other AOV (such as Z, P, cryptos...) would be in another exr as well.

so as an example if I have 2 lightgroups named key and rim I would have a exr with beauty and the tech aovs and a second exr with key + key diffuse direct + key diffuse indirect + key specular direct + key specular indirect +key sss direct + key sss indirect + key sheen direct + key sheen indirect + key transmission direct + key transmission indirect and a third exr rim with all its aov as well.

Is it something doable in MtoA ? Can we have separated but merged aovs ? Would it be through the arnold driver ? or the path of the file output ? Something else ?

thanks in advance,

Cheers

[Stephen.Blair · Accepted solution]

Yes, but you have to set up driver nodes manually in the Node Editor.
I have a screenshot somewhere, let me find it...

Update: You'd probably have to create custom AOVs for all the light group AOVs, so that could control what driver writes out the light group AOVs. If you let MtoA do the light group AOVs automatically, then the light group AOVs will go into the same EXR as the main AOV

Here's how I would do it.
In this example, there are two light groups, named "area" and "yellow"

[sbauCZF28]

Hi !
Thanks Stephen, that's really helpful ! We are gonna try to automatize that and try it.

(and sorry for the delay, I didnt see the email... )

Cheers !