Is it possible to save out the density channel when simming with stoke? I am using a PRT fume as a source which has a density channel. But the simmed PRTS are missing the density channel.
I am trying to color based on density using a gradient.
Did you check the Density channel on the list of channels to save in the Stoke Particle Simulator?
There are several ways to acquire a channel from a source:
When the channel is checked on the list of channels under the Distribution Sources rollout of the Stoke Particle Simulator, the value of the channel is taken at birth, and will retain that value throughout the simulation.
If you want to update the channel on every step, you could use the new Per-Step Magma operators to sample the data from a PRT FumeFX (or anything else). Again, the channel in question must be checked on the list of channels to save to be stored in the PRTs. You could use a NearestParticle operator to read the channel from the nearest PRT FumeFX sample, or sample the FumeFX directly using an InputField node.
You can also sample the channel on the fly using a Krakatoa Magma modifier on top of the stack of the Stoke Particle Simulator. The values will not be stored in the base PRTs, but can be changed dynamically without resimulating.
If the source is a Stoke Field Loader instead of a FumeFX simulator, a PRT Field could be used in place of a PRT FumeFX object. However, in this case the Smoke channel will show up on the list of channels (PRT FumeFX renames Smoke to Density implicitly). So you would have to actually store the Smoke channel in the PRTs, and set up your Magmas to use Smoke instead of Density, but the general workflow would be the same.