RigidBody SetCenterOfMass

Urho3D’s current implementation of RigidBody has a mechanism to offset the center of mass for models whose origin does not coincide with the center of mass.
But it is private, and read-only!
There is a GetCenterOfMass method, but no SetCenterOfMass method.
It would be useful for me to be able to set that variable without having to hack the motionstate.

I have a model of a barrel, its origin is in the middle of one of the two endcaps.
When I apply a cylinder shaped rigidbody to it, the center of mass is at the origin of the model, which is completely wrong and leads to unexpected physical behavior. I shouldn’t have to edit the model to make the origin coincide with the center of mass!


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hai, thanks for useless information - I already know about the motion state offset transform that Urho hides from us.

Please be civilized and mind the language.

My apologies, just frustrated with roadblocks.

It’s not well documented, but Urho’s RigidBody class derives from btMotionState, and therefore implements that interface. This includes public access to “btTransform m_centerOfMassOffset” class member, so no workaround is needed to directly write to that offset transform.

This was a non-issue, so I’ve entirely made a fool of myself!
Would it be possible to include a mention in the docs to highlight the fact that Urho’s RigidBody effectively “is a” btMotionState - thereby granting full access to the center of mass offset transform?

This is a handy arrangement, though it is not obvious, that RigidBody “is a” btMotionState, which “has a” btRigidBody (which “has a” btMotionState)