I've been trying to figure out the best way to use ID passes in Natron.Right now I'm trying some hacks with a grade node and setting white- and blackpoints to the index of the mask I want, basically converting index data to color data.But is there a correct way to use an integer ID pass in Natron to get a perfect mask?
Checkout this link at https://www.facebook.com/groups/NatronNation/495822017252038/. It has PyNodes developed by Francois Grasshard. One of the PyNodes is called ID Mask for your request. Make sure that you change the Merge node mode to different instead of copy. Due to many changes that went on in Natron's Python API, The Merge node in the ID-Mask group didn't get updated in time.
Sorry for any inconvenience.
Note that in general iit is a bad idea to use objectid, because it is not antialiased.This is probably the reason why even Nuke doesn't have this capability built-in (you have to use J_Ops)If you render separate antialiased mattes for each object, they can be used as masks in any operation.I may make an ID plugin in the future, though. Please file an issue in http://github.com/devernay/openfx-misc/issues if you want one.
Thanks for all the info!I'll give those scripts a whirl and see what they can do.You're right about the ID passes, I prefer rendered masks too, I was just wondering if there was support for it built in to Natron.
Hey! I'm now having the same question as I try to use Object and Material ID rendered form Blender Cycles.
About the rendered masks - how would I go about making that?
I'll typically toss the passes (a main render and ID passes) into an Open EXR multi layer format in Blender. In Natron, it's a simple matter to read in the EXR and set it to whatever layer you want. Then you can go about using that in compositing.
another solution is to use this to key the ID : https://github.com/NatronVFX/natron-plugins/tree/master/Keyer/IDKeyerOne simple way of getting colored ID pass in blender is to plug the ID output into a normalize , then into a coloramp.
For aliasing issue you can look into this : https://github.com/NatronVFX/natron-plugins/tree/master/Filter/AntialiasingIt's far from perfect, but you can try and see if that works for you ...