Jonathan Mack

Gone!

Particle systems, and all related nodes and contexts were removed in 17.5. They have been considered legacy and hidden for several versions now.

DOP based particles are the replacement, although they are not identical. Old tutorials using the old particle system tools will be difficult to follow verbatim. I recommend following a few newer particle tutorials that use the dop-based systems.

I'm not familiar with how the redshift volume material is supposed to work, but that emission ramp has a non-zero value for the minimum. I would expect that to create a solid color everywhere heat is 0. Maybe it needs to be multiplied by another field? The mantra pyro material uses two fields for emission, one for color and one for emission brightness.

I think it depends, but normally it doesn't linearize because converting to RAT doesn't change the bit depth unless you manually specify ‘-d real16’ for example. If manually upgrading the bit depth from int8 to real16 or real32 the image is normally automatically linearized.

See the help for the icp command for more details