applyImpulse relative to object

[rscottfree]

applyImpulse relative to object

[rscottfree]

After a lot of messing around and some help from someone who actually knows physics, I found out how to do this--it's pretty simple, actually.

If you have a force, like Vector3(0, 100, 0), you can apply that to an object relative to itself by multiplying it by the object's matrix.

So, if you have a box mesh, box, and your force, var force = THREE.Vector3(0, 100, 0), you do something like this to get the actual force you are going to apply to the box:

var newForce = box.matrix.multiplyVector3(force);
box.applyCentralImpulse(newForce);

This will apply the force in the Y direction of the object instead of the Y direction of the scene.

[chandlerprall]

You beat me by an hour :) I'm glad the solution I was thinking of is what worked for you, haha.

Enjoy the library!

[rscottfree]

Actually, the way I did this turned out to cause me a lot of head-scratching issues (like velocities getting out of control). For an explanation of how I got this working, see this comment on a related issue.

In short, you have to extract the rotation matrix of the object and multiply the force vector by that, then apply the resulting vector back to your object.