Hi there! I am new here but I use Trapcode a lot of times.
In first, I would like to thank Mr.Peder Norrby by creating Trapcode. All days in TV advertisements I can see in action Shine and 3D Stroke. It is simple amazing :P
Ok, let's us go to the question: why can't we use bouncing and air physics model at the same time?
Sometimes I miss turbulence field and spherical field when I use bouncing. Motion path should be enable while using Bounce mode, so we could create a path and then make the particle to bounce somewhere.
Everything is possible :) But combining the Air and Bounce modes is EXTREMLEY hard, that is why the feature is not there, it would takes months or even years to figure out exactly how to do it. Maybe it will be added in the future... I also have ideas for other products where such combinations would be easier (built on an entirely different technology).
Anyway, I have added it as a feature request for Particular.