Raycasting ahead of moving object

[markhula]

Hi all,

My lead object has a rotation I cam access via:

obj->_SIO2objectphysic->_btRigidBody->getWorldTransform().getBasis();

And a direction facing/moving vector btVector3 facing

I wish to raycast from this main object but ahead of itself and in the direction facing and slightly lower than it's current Z

I assume I have all the information I need to do this without resulting to sin/cos and moving the end ray point around in a standard manner.
Just a bit lost on how I use the main character's orientation/facing vector to position the ray endpoint.

Any help appreciated.

Cheers

[markhula]

Hi all,

I've achieved almost what I want with :

btVector3 b;

btTransform tr;
tr= obj->_SIO2objectphysic->_btRigidBody->getWorldTransform();

b=tr.getOrigin();

float ya,pi,ro;

orn.getEuler(ya,pi,ro);

b.setX(b.getX()+cos(pi));
b.setY(b.getY()+sin(pi));

As I assume it's a quaternion being converted to euler it only works for half the rotation. What do I do to make the other half ok? (as quats only do upto 180 degrees I believe....)
Secondly; this seems really, really inefficient - is there a better way???? - is it better to rotate with the quaternion returned rather than convert via geteuler? (if so how)

Thanks in advance

[markhula]

Ok, got it working.

But again, it seems a really inefficient way; is there a better method?
Which is more expensive a raycast or having a dummy collision object in front the object and looking at that for collisions??

Thanks