kivutar
commented
12 years ago Lirmont coded it here http://ffhacktics.com/smf/index.php?topic=7811.0 . The code is bigger than expected because Panda3D does not support particle collision yet. So the last code does not use the particle system. This code still have to be integrated into the main trunk. Maybe by creating an abstraction layer over regular particles and these custom particles. We have to re-think weather.
Implement the rain effect using the particle system, and add it on a map in game (let's say Orbone Monastery). You can open the already existing snow effect using Tut-Particle-Panel.py in Panda3d samples.