calculate size of frustum as a function of z distance to camera

hi,

i want to create a rectangle which fills the screen exactly, example:

camera.position.z = 500;
...
var cube = new THREE.CubeGeometry( 1, 1, 1);
...
cubeMesh.position.x = 0; cubeMesh.position.y = 0; cubeMesh.position.z = 0;
cubeMesh.scale.x = ???;
cubeMesh.scale.y = ???;

so here is the distance from the camera to the object 500. is there a easy way to calculate ???

[alteredq]

Usually for having screen-filling rectangle we use OrthographicCamera and then just create window-pixel sized PlaneGeometry.

See for example here:

https://github.com/mrdoob/three.js/blob/master/examples/webgl_postprocessing_dof.html#L240

https://github.com/mrdoob/three.js/blob/master/examples/webgl_postprocessing_dof.html#L264

(for things like HUD the easiest is to have a separate scene just used for sticking things to the screen)

If you need a distance from object to camera, it can be computed using world matrices:

var point1 = camera.matrixWorld.getPosition().clone();
var point2 = cubeMesh.matrixWorld.getPosition().clone();

var distance = point1.distanceTo( point2 );

[WestLangley]

@bbnnt Your best bet for help is now stackoverflow.

http://stackoverflow.com/questions/15331358/three-js-get-object-size-with-respect-to-camera-and-object-position-on-screen/15331885#15331885