How to prevent ray collisions with certain meshes

Questions
1

Im using
ray = new Ray(B2, new Vector3(0, -1, 0), 1000);
hit = scene.pickWithRay(ray);

to look for the point of collision between the ray and a specific mesh, but I have other meshes that are interfering and receiving the hit instead, how can I hide, disable, prevent etc other meshes from appearing in the hit collisions?

thank you :slight_smile:

2

found solution doing
mesh.isPickable = false;

1 Like
3

Other solution is to pass a predicate as the 2nd parameter of scene.pickWithRay.

1 Like
4

@Evgeni_Popov that´s very nice Evgeni, so I can tell it to only look for collisions with a specific mesh, thats also a great way yeah

5

@Evgeni_Popov what does it mean a “predicate” ? I am trying this:
hit = scene.pickWithRay(ray, mhr[mcur]);
putting the mesh that I care about, and it gives error “TypeError: predicate is not a function”,
what kind of a parameter is this predicate, any examples around? do I have to set a function that returns the mesh? or?
I tried this:

hit = scene.pickWithRay(ray, ()=>{return mhr[mcur];});

and then I don’t get error, but I don’t get any collisions either :slight_smile:

by the way mhr[mcur] is the variable of the mesh I care about

6

The predicate in this case is simply a function that takes a mesh as a parameter and should return true or false to indicate that this mesh should be tested or not.

hit = scene.pickWithRay(ray, (mesh)=> { return mesh.name === "mymesh"; });

You can of course put the logic you want inside the function:

mymesh = new BABYLON.Mesh(...);
hit = scene.pickWithRay(ray, (mesh)=> { return mesh === mymesh; });

const meshesToTest = {};
meshesToTest[mesh1.uniqueId] = true;
meshesToTest[mesh2.uniqueId] = true;
...
hit = scene.pickWithRay(ray, (mesh)=> { return meshesToTest[mesh.uniqueId] === true; });
2 Likes
7

very helpful thank you very much :slight_smile: