Get visible meshes. Octree?

[viktov]

Hi,

 

I wonder what is the best way to get only these meshes which are visible by camera at the moment.

I know there is octree implementation in babylon, but Im not sure how to use it.

I've seen this https://github.com/BabylonJS/Babylon.js/wiki/Optimizing-performances-with-octrees

but still have problems to make it work.

 

If someone could explain (write a piece of code or pseudo code) how to make it.

Lets say I have 5 cubes on my scene and a free camera.

I would like to have a function that would return meshes which are visible in a viewport of my camera.

 

Thank you,

Regards

V.

[celian-garcia]

Hey !

There is a BABYLON.Scene function named isActiveMesh(mesh) :

 

It returns true if the mesh in parameter is active (visible from the camera) and false otherwise.

 

I hope it will help you.

[GameMonetize]

You also have a list of active meshes: scene.getActiveMeshes which is a smartArray of active (visible) meshes

[viktov]

Thank you

[Gil]

Hello, I came by to that post. The functions are usefull but are not precise enough to know if a mesh is drawed or occuled.

At least not with my tests.

[aWeirdo]

@Gil

You can also build your own array with camera.isInFrustum(mesh)

var meshesInFrustum = [];

function updateFrustum(){

  meshesInFrustum.length = 0;

  for(var i = 0, length = scene.meshes.length; i < length; i++){
    var mesh = scene.meshes[i];
    if( mesh && mesh.isVisible && camera.isInFrustum(mesh) )
      meshesInFrustum.push(mesh);
  }

}

scene.registerBeforeRender(function(){
    updateFrustum();

});

http://www.babylonjs-playground.com/#LB6QV9

[Gil]

@aWeirdo 

That's a cool solution !

Thanks !

 

I just tested and that still don't take into account if a mesh is occuling another.
http://www.babylonjs-playground.com/#LB6QV9#1

I'm looking for a different way to solve my issue by checking if a mesh is facing the current camera to do what I want.

Edited April 13, 2017 by Gil
I tested the code