How to trace a line between 2 mesh and check for a collision ?

[elkyu]

Hi again !

 

I have a plane with an other mesh behind.

 

I would like, when I click on the plane, trace a line directed to the back of the plane, and verify if there is a collision or not with the other mesh. 

 

I think I can create a line mesh, and update its size and check for a collision on each frame. No ? Maybe there is an other way ? 

 

Thanks

[RaananW]

Hi,

You could use ray tracing for that.

Where does the line start? At the mouse click position?

Drawing the line can be done even after you already know if there is a collision.

[elkyu]

Yes the line should start at the mouse click position.

 

I want to know if at the mouse click position on the plane there is a match(collision) at the same coordinate somewhere behind the plane. Trace a line is just an idea 

 

But, I forgot an important detail ... Between my plane and my other mesh I have an other plane which I want to ignore

[RaananW]

That's simple -  the scene.pick function accepts a predicate - this is a function that defines which meshes shouzld be picked and which shouldn't.
so (for example):

scene.pick(scene.pointerX,scene.pointerY, function(mesh) { return mesh.id == "idOfMeshToBePicked" })

You could also use the scene.onPointerDown and set the isPickable value to false to unpickable meshes and true to the pickables.

Like this - http://www.babylonjs-playground.com/#3TCRC

[elkyu]

I can set true just to the pickable mesh behind the plane because I need a pickinginfo on the plane too.

 

Your first solution works very well ! I defines the mesh behind the plane "pickables" with its ID and it works !

 

Thanks !