How to use Scene.pickWithRay ?

[kevzettler]

I'm trying to pick a mesh with Scene.pickWithRay and having problems.

	    var pickResult = scene.pickWithRay(ray, function (mesh) {
	      if (mesh.voxelData) {
	        debugger;
	        return mesh;
	      };
	    });

	    var mesh = pickResult.pickedMesh; //Get the mesh picked

I can trigger the debugger statement no problem with the mesh I want.

The mesh looks like it has the required properties:
 

mesh.isPickable
true
mesh.isEnabled
function (){return!!this._isEnabled&&(!this.parent||this.parent.isEnabled())}
mesh.isEnabled()
true
mesh.isVisible
true

I'm not sure what to do in the predicate function. The docs could be more clear: http://doc.babylonjs.com/classes/2.5/scene#pickwithray-ray-predicate-fastcheck-rarr-pickinginfo-classes-2-5-pickinginfo-

I've tried returning true and returning the mesh. Both situations `pickResult.pickedMesh` is undefined.

[RaananW]

Hi,

might it be that the ray is not hitting this mesh? Wanna share a simple playground?

[kevzettler]

@RaananWWould the mesh show up in the predicate if it wasn't being hit?
 

scene.pickWithRay(ray, function (mesh) {
//The mesh I want is available here
});

 

[RaananW]

the predicate is a function that is executed on each and every mesh in the scene. this is how you filter your meshes. if you return true, all meshes will be inspected using this ray.

[haestflod]

In the predicate function you write your own logic of what meshes should be valid or not for picking.

In your case that is if the mesh has voxelData so what you should do there is return true. As long as mesh has voxelData it will be checked against the ray. Just because the predicate function returns true doesn't mean the ray will hit.
So as RaananW said if your debugger statement is executed the ray most likely doesn't hit your mesh.
 

[getzel]

Hello,

there is a predicate part in my raycast tutorial :

http://doc.babylonjs.com/tutorials/raycasts

 

draw the ray : ray.show(scene, new BABYLON.Color3(1, 1, 0.1));

 

 

[kevzettler]

Ok thanks for clarifying. Is there a helper I can use to draw the Ray to confirm? 

[adam]

This PG doesn't use scene.pickWithRay, but it could still be helpful:

http://www.babylonjs-playground.com/#ZHDBJ#36

[RaananW]

On 3/3/2017 at 9:11 PM, kevzettler said:

Ok thanks for clarifying. Is there a helper I can use to draw the Ray to confirm? 

Funny you say that, it is actually called RayHelper  

[kevzettler]

@RaananW hahah yeah I should have looked harder. Got it all sorted out though thanks for the help everyone!