I need a little tutorial on how to use PhysicsRay…
Here is my little piece of code:
PhysicsRay r;
r = tank.createRay("ChaseRay");
Now I have two questions:
1) How can I position the Ray orthogonally to a certain object(tank is a DynamicPhysicsNode, obviously)?
Currently I solved my problem like this:
r.getLocalTranslation().set(0,-200,0)
2) Which Method do I have to use to check if my Ray collided with another object?
I already checked with findPick(Ray, PickResults), but its not compatible with PhysicsRay...:(
PhysicsRay generates events as other physics geometries do. Have a look at the physics tutorial and tests. There's a test for rays as well.
The Ray class is for picking. Maybe you want to use that instead? What do you try to achieve? And what means "orthogonally to a certain object"? A straight line can be orthogonal to a plane, but what would be the plane of your "object"?
This is pretty much pushing, isn't it? My topic is also very urgent (think we've got the same DEADline ;)). Hope you'll find any help, unfortunately I have no idea of PhysicRays…
This is pretty much pushing, isn't it? My topic is also very urgent (think we've got the same DEADline ;)). Hope you'll find any help, unfortunately I have no idea of PhysicRays...
Kind regards, Jan ;)
Yeah well, maybe I was getting a little emotional...^^
Sorry for that, I didn't mean other projects are less important, but my headache becomes stronger and stronger...
irrisor said:
PhysicsRay generates events as other physics geometries do. Have a look at the physics tutorial and tests. There's a test for rays as well.
The Ray class is for picking. Maybe you want to use that instead? What do you try to achieve? And what means "orthogonally to a certain object"? A straight line can be orthogonal to a plane, but what would be the plane of your "object"?
First of all, thanks for replying :)
I tried with the CollisionEventHandler, but I've seen, that this was the wrong way...
So, maybe when I explain, what I am trying to do this will bring light into the discussion:
First of all I am coding a tank game. I am generating a floor (consisting of several boxes) with walls on it.
like the one in attachment 1.
I placed into the floor (walls excluded) little disks (but not visible, you can see an example how they are placed in attachment 2) which I use for checking if a Ray going through the ground collided with one of these disks. An abstract example is shown in the 3rd attachment.
and now how I programmed it:
Vector3f worldCoords,worldCoords2;
worldCoords = tank.getLocalTranslation(); //get the location of our tank
worldCoords2 = tank.getLocalTranslation();
worldCoords2 = worldCoords2.add(0,0,-10); //subtract now 10 from it
r = new Ray(worldCoords, worldCoords2
.subtractLocal(worldCoords).normalizeLocal());
pr.clear();
floor.findPick(r, pr); //finds nothing :(
// ...
If I try to do it with rootNode I get a ODE internal error 2.
If I try to do it with rootNode I get a ODE internal error 2.
Ray has nothing to do with ODE. That error means you were altering the scenegraph (at least the physics part) while ODE was taking a simulation step. Thus make sure that 1) you do not alter the data while checking rays (beware: getLocalTranslations() get a reference to the position data) and 2) you don't use threads or use proper locking to avoid modification while in simulation step (PhysicsSpace.update).
So essentially: pick on rootNode should work without any ODE errors.
Well, this was the problem...^^
But the collisions are not recognized very well...Oo
Many thanks!!!!
irrisor said:
Alessandro said:
If I try to do it with rootNode I get a ODE internal error 2.
Ray has nothing to do with ODE. That error means you were altering the scenegraph (at least the physics part) while ODE was taking a simulation step. Thus make sure that 1) you do not alter the data while checking rays (beware: getLocalTranslations() get a reference to the position data) and 2) you don't use threads or use proper locking to avoid modification while in simulation step (PhysicsSpace.update).
So essentially: pick on rootNode should work without any ODE errors.
As far as I know there are no other threads, which could interfere with the ODE simulation.
I modified the code to use no references and this method works now without ODE errors :) thanks
Thanks for helping me out, I think I can solve the problem now for myself... But I will post the final solution for others having a similar problem.
