I have the mesh lights contribution in the beauty pass only. I want to separate the contribution of mesh ligths if possible to manage in compositing. Didn't found the method to do that.
Thank's for your help.
I would use light groups. Put the mesh lights in their own light group, and then have an AOV that includes just that light group.
I am assuming you have the latest MtoA.
I tried to make custom AOV with LPE = C.*<L.'SPHERE'>
but mesh in own light group always appears completely black.
Or am I doing it wrong ?
mesh light work with light groups. If SPHERE is what you entered in the AOV Light Group text box, then that LPE will work for the light contributions in the scene.
The actual mesh lights, if they are visible, will show up in the emission AOV.