THREE.js check if object is in frustum

问题

i've been tinkering around with three.js and i have a canvas i'd like to use as kind of a GUI. for that i have to check if an object is in the camera frustum.

my current code:

camera.updateMatrix(); 
camera.updateMatrixWorld(); 

var frustum = new THREE.Frustum();
var projScreenMatrix = new THREE.Matrix4();
projScreenMatrix.multiplyMatrices( camera.projectionMatrix, camera.matrixWorldInverse );

frustum.setFromMatrix( camera.projectionMatrix );

if(frustum.containsPoint( mesh.position )){
    //stuff happens...
};

frustum.containsPoint()keeps returning false. what am i doing wrong here?

回答1:

Your code is using

frustum.setFromMatrix( camera.projectionMatrix );

But that isn't the matrix you want. Instead use:

frustum.setFromMatrix( new THREE.Matrix4().multiplyMatrices( camera.projectionMatrix, camera.matrixWorldInverse ) );

as answered in How to determine if plane is in Three.js camera Frustum

来源：https://stackoverflow.com/questions/24877880/three-js-check-if-object-is-in-frustum