These are chat archives for highfidelity/hifi

19th
May 2017
Rob Kayson
@MrRoboman
May 19 2017 16:18
Seems to be an issue with a dynamic body becoming inactive. EntityMotionState.cpp:103 is the culprit... the _serverPosition is the difference of the child position and the parent position and it sets the child's position.
Seth Alves
@sethalves
May 19 2017 16:36
currently, when entities are made to be a child of something else, we force it to be "kinematic" in bullet
this is going to make it behave strangely, if it was dynamic
we would like to change things so that the parent's collision hull changes to include the child, but we haven't done it yet
Rob Kayson
@MrRoboman
May 19 2017 16:42
Meaning child collisions are updated from parent physics collision step instead of the child's?
Seth Alves
@sethalves
May 19 2017 17:33
you sort of end up with unpredictable behaviour. The entity-tree is updating the child based on the parenting rules and bullet is updating it based on its own simulation, and they don't match, so they fight. you get that flickering and other bad behavior.
you might have better luck attaching the dart via a constraint
a hinge or slider constraint with the range clamped all the way down
you wont be able to far-grab it away from the target, though
The target is moving?
Rob Kayson
@MrRoboman
May 19 2017 18:42
Potentially. You can throw the dart at anything.
Would you point me in the direction of an example of hinge or slider constraints.
constraints haven't been in there very long -- let me know if you have trouble with them
Rob Kayson
@MrRoboman
May 19 2017 20:20
Thanks @sethalves