Isolate niagra fluids in MRQ (objectID)

Hi, I can’t seem to isolate fluids in MRQ at render time. They don’t seem to work with Object ID/ Cryptomatte either as Actor based, Material based or Layer based. Do I have to change the emitter settings to expose the Object ID? I just need to isolate it for compositing purposes… thanks in advance for any help

One fix is just to do an opacity PP Material and apply to the entire scene (ie a luma matte which can be used in your compositing package eg after fx track matte) . This requires an additional render but is very fast and simply gives you a matte to cut out all objects in the scene form the (transparent) background.

There is a plugin called Niagara MRQ support and previously i did not have this loaded. Not sure what it does but I’m presuming this was the cause of the smoke not being present in the cryptomattes?

So this is all good now?

Thanks for the reply- Not quite yet, still don’t have a fully functioning cryptomatte, but as soon as i do i will report back…