simple ray collision test?

[AndyBeaulieu]

I have read the basic tutorial for collision detection here - http://github.com/BabylonJS/Babylon.js/wiki/10-Object-collisions

 

But what I want to do is shoot a ray straight down in the Y from a one mesh and see where it intersects with a second mesh. The first mesh is a simple sphere, but I want to snap it to a second mesh that is has vertices data (elevations). 

 

So in this video here - http://www.youtube.com/watch?v=0S08faz1JpE&feature=youtu.be

... you will see a bunch of yellow spheres that appear above mesh tiles. I would like to snap those to the mesh tiles that are directly below them.

 

What is the best way to do this?

 

Thanks in advance!

[GameMonetize]

Hello,

 

you can use scene.pickWithRay(ray, predicate)

 

ray is a...ray (BABYLON.Ray) and predicate can be null or a function(mesh) returning true or false if you want to test against specific mesh

 

pickWithRay will return a pickInfo object with pickedPoint property

[AndyBeaulieu]

Sorry, I am not understanding pickWithRay...

 

Here is a simple jsbin - http://jsbin.com/eHEMaLUJ/2/edit?html,output

 

The sample has a sphere located at (0,20,0) and a plane located at (0,0,0).

 

I want to find the intersection point of a ray shot from the sphere straight down the Y, to the plane. So I do: new BABYLON.Ray(sphere.position, new BABYLON.Vector3(0, -500, 0));

 

I would expect the pickedPoint to be equal to where the ray intersects plane, but instead I get pickedPoint = (0, 19.96, 0).

[GameMonetize]

The direction of the ray should be normalized. if you use new BABYLON.Ray(sphere.position, new BABYLON.Vector3(0, -1, 0)) it should work:)

[AndyBeaulieu]

Thanks, that was too easy

 

I updated the jsbin if anyone needs a sample - http://jsbin.com/ubAwapU/3/edit?html,output

 

Thanks!