Get the physics control from the spatial or the opposite

Troubleshooting physics
1

Hi, my program does something simple. You select an object clicking it, you move it dragging the mouse, and then you drop it clicking again in a location. While the object is dragged, it’s spatial is painted wireframe, as a form of feedback.

Now I want to add collisions, so you can’t drop an object where there’s already one. I know from the tutorial you have to add a PhysicsControl to the object, and you must call setPhysicsLocation() on the control instead of setLocalTranslation() on the spatial.

Currently, I have a “picked” spatial as a member of the simple application that is what I use to paint the dragged object. Now if I must use setPhysicsLocation() to move it, I must have also the control around.

Is there a way to only use one of them, and get one from the other? Or which approach do you suggest?

2

Not sure if it’s what you’re looking for but you can do.
spatial.getControl(PhysicsControl.class);
and
control.getSpatial();

3

Do you want it to block if its put somwhere wher eit should not or only to be like red wireframe for no not there?

I suggest using a ghost physic thing, it only gives you collision events, but does not actually collide.

4
<cite>@nehon said:</cite> Not sure if it's what you're looking for but you can do. spatial.getControl(PhysicsControl.class); and control.getSpatial();

spatial.getControl seems like it could work. But control.getSpatial() seems not to exist, at least on RigidBodyControl.

<cite>@Empire Phoenix said:</cite> Do you want it to block if its put somwhere wher eit should not or only to be like red wireframe for no not there?

I suggest using a ghost physic thing, it only gives you collision events, but does not actually collide.

The red wireframe when in collision would work fine, and a condition that do not let the object be dropped when collision. How does this ghost physic work? Is it like this? (I found that after writing the question).

5
<cite>@jmonillo said:</cite> spatial.getControl seems like it could work. But control.getSpatial() seems not to exist, at least on RigidBodyControl.
uh, you're right.... I could have bet on this. There is only the setSpatial.
6
<cite>@jmonillo said:</cite> How does this ghost physic work? Is it like this? (I found that after writing the question).

Thats a geometry collision.

Ghostcontrols are for physics collisions:
http://code.google.com/p/jmonkeyengine/source/browse/branches/jme3/src/jbullet/com/jme3/bullet/control/GhostControl.java?r=6629

Keep it mind that they use the Bounding box of the collisionshape

7

If you use physics collisions, the callback from physics includes the spatials that correspond to the physics objects that are colliding.

https://wiki.jmonkeyengine.org/legacy/doku.php/jme3:advanced:physics_listeners

[java]
public void collision(PhysicsCollisionEvent event) {
if ( event.getNodeA().getName().equals(“player”) ) {
final Node node = event.getNodeA();
/** … do something with the node … /
} else if ( event.getNodeB().getName().equals(“player”) ) {
final Node node = event.getNodeB();
/* … do something with the node … */
}
}

[/java]

8

Ok, many thanks for the answers.

Now I’m currently thinking about using physics collisions or simple triangle collisions. And I still have to analize your answers to fully understand them.

But I think we can consider that the question is solved, because my next doubts will be about the problem. Thanks, again.