So on “contact_point_response” you store the conPos and on “collision_response” you use whatever value is in “conPos” to play a particle effect at that position?
Note that there is not a 1:1 relation between contact_point_response messages and collision_response messages. contact_point_response can be sent multiple times per frame while collision_response happens once per frame. I’m not sure the order of these two messages is guaranteed either.
Can’t you play the particle effect immediately when you get the “contact_point_response” instead of waiting for “collision_response”?