I am familiar with the old Pyro Shader node, but have come across the Karma Pyro Shader node in Solaris. What, if any, are the differences and advantages of using the Karma Pyro Shader?

The old Pyro Shader has a useful button for adding passes like pyro_scatter to Mantra but this does not function with Karma.

I can only see the C_emission AOV for view in Karma if using pyro Shader material, so presumably this is all you have to use?

The Karma Pyro Shader, however, adds aov_scatter and aov_fire AOVs for use. You also still have C_emission AOV.

When compositing an explosion in Nuke, do you generally just use C_emission and the various light AOVs to recreate the beauty pass for an explosion?

What would be the use of the aov_scatter or pyro_scatter AOV?

Also, What is the combined_volume AOV used for?