private CollisionShape rotate(CollisionShape shape, Quat4f rot) {
if (shape instanceof BoxShape) {
BoxShape box = (BoxShape) shape;
javax.vecmath.Vector3f extents = box.getHalfExtentsWithMargin(new javax.vecmath.Vector3f());
com.bulletphysics.linearmath.QuaternionUtil.quatRotate(VecMath.to(rot), extents, extents);
extents.absolute();
return new BoxShape(extents);
} else if (shape instanceof CompoundShape) {
CompoundShape compound = (CompoundShape) shape;
CompoundShape newShape = new CompoundShape();
for (CompoundShapeChild child : compound.getChildList()) {
CollisionShape rotatedChild = rotate(child.childShape, rot);
javax.vecmath.Vector3f offset =
com.bulletphysics.linearmath.QuaternionUtil.quatRotate(
VecMath.to(rot), child.transform.origin, new javax.vecmath.Vector3f());
newShape.addChildShape(
new Transform(
new javax.vecmath.Matrix4f(VecMath.to(Rotation.none().getQuat4f()), offset, 1.0f)),
rotatedChild);
}
return newShape;
} else if (shape instanceof ConvexHullShape) {
ConvexHullShape convexHull = (ConvexHullShape) shape;
ObjectArrayList<javax.vecmath.Vector3f> transformedVerts = new ObjectArrayList<>();
for (javax.vecmath.Vector3f vert : convexHull.getPoints()) {
transformedVerts.add(
com.bulletphysics.linearmath.QuaternionUtil.quatRotate(
VecMath.to(rot), vert, new javax.vecmath.Vector3f()));
}
return new ConvexHullShape(transformedVerts);
}
return shape;
}