mParticles are great. It is well implemented into the pflow system allowing great control. Moreover, it is incredibly fast. To be honest, if it wasnt mParticles, I probably would have dumped 3ds Max entirely years ago.
On the other hand, it is not actually perfect. Stability issues may be another topic but there is a very small but yet very annoying issue I have been experiencing for years.
Somehow the collider objects with the PFlow Collision Shape modifier tends to de-activate themselves. The ‘activate’ button on the modifier seems ‘on’, but actually collision is not working. The only solution I could find was to de-activate and re-activate all the collision objects when this situation occurs.
The real problem is, this situation occurs every time a new scene opened… Save your project and open it again next day and all colliders must be re-activated.
So I have written a small startup script to search and re-activate all the collider objects on each time a new scene loaded.
save this code under localappdata%\Autodesk\3dsMax\<3ds Max Version>\ENU\scripts\startupfolder and you will make sure that all the colliders are working when you open a scene with mParticles.
fn reactivateColliders = ( for i in objects do try i.modifiers[#PFlow_Collision_Shape].active = off catch () for i in objects do try i.modifiers[#PFlow_Collision_Shape].active = on catch () format "% --> re-activated colliders\n" (maxfilepath + maxfilename) ) callbacks.removescripts id:#my_postload callbacks.addscript #filePostOpenProcess "reactivateColliders()" id:#reactivateColliderObjects