Question

I am trying to detect an intersection by using a raycast. My current problem is that I am not sure about my raycast aiming into the desired direction. So my general question is: Is there a way to make a raycast visible? And if so: How is it done? This would help me a lot.

Michael

Answer 1

Why dont you draw a line from your origin to the direction of the ray.

To be more specific (using r83):

    // Draw a line from pointA in the given direction at distance 100
    var pointA = new THREE.Vector3( 0, 0, 0 );
    var direction = new THREE.Vector3( 10, 0, 0 );
    direction.normalize();

    var distance = 100; // at what distance to determine pointB

    var pointB = new THREE.Vector3();
    pointB.addVectors ( pointA, direction.multiplyScalar( distance ) );

    var geometry = new THREE.Geometry();
    geometry.vertices.push( pointA );
    geometry.vertices.push( pointB );
    var material = new THREE.LineBasicMaterial( { color : 0xff0000 } );
    var line = new THREE.Line( geometry, material );
    scene.add( line );

Codepen at: https://codepen.io/anon/pen/evNqGy