How to get the velocity of rigid body
-
- Posts: 33
- Joined: Fri Jun 05, 2020 8:36 am
How to get the velocity of rigid body
I want to get the velocity of a rigid body in motion. How can I get it? Thank you very much.
-
- Posts: 849
- Joined: Tue Sep 30, 2014 6:03 pm
- Location: San Francisco
-
- Posts: 33
- Joined: Fri Jun 05, 2020 8:36 am
Re: How to get the velocity of rigid body
Thank you very much, but the return value I get is btVector3, how can I convert it to speed?
-
- Posts: 849
- Joined: Tue Sep 30, 2014 6:03 pm
- Location: San Francisco
Re: How to get the velocity of rigid body
Speed is the magnitude of velocity --> compute the length of the btVector3.
-
- Posts: 33
- Joined: Fri Jun 05, 2020 8:36 am
Re: How to get the velocity of rigid body
This seems to be the speed of each frame. What should I do if I want to get the speed per second? Thank you for your time
-
- Posts: 849
- Joined: Tue Sep 30, 2014 6:03 pm
- Location: San Francisco
Re: How to get the velocity of rigid body
speed = deltaDistance / deltaTime = meters /second
acceleration = deltaSpeed / deltaTime = meters / second^2
There is no RigidBody::getLinearAcceleration() method in the API.
There is a RigidBody::getGravity() method which would provide the free-fall acceleration sans collisions.
To measure the true effective acceleration of the object you must do it manually, which would require you to remember the lastTime and lastVelocity from the previous measurement. In pseudo code it might look something like:
acceleration = deltaSpeed / deltaTime = meters / second^2
There is no RigidBody::getLinearAcceleration() method in the API.
There is a RigidBody::getGravity() method which would provide the free-fall acceleration sans collisions.
To measure the true effective acceleration of the object you must do it manually, which would require you to remember the lastTime and lastVelocity from the previous measurement. In pseudo code it might look something like:
Code: Select all
thisTime = getTimeNow()
thisVelocity = getLinearVelocity()
deltaVelocity = thisVelocity - lastVelocity
deltaTime = thisTime - lastTime
acceleration = deltaVelocity / deltaTime
lastTime = thisTime
lastVelocity = thisVelocity