THREE.js camera following a specific path

Question

I'm trying to make a game with THREE.js. I have a path with a lot of curves combined with some straight paths.

I found an example on Internet and tried to implement TrackballControls.js to make the camera follow a line, but the camera doesn't lookAt the front, it moves weird.

Here is the code:

var controls = new THREE.TrackballControls(camera, render.domElement);
var numPoints = 50;
spline = new THREE.CatmullRomCurve3([
    new THREE.Vector3(0, 0, 0),
    new THREE.Vector3(50, 0, 0),
    new THREE.Vector3(0, 0, -100)
]);

var material = new THREE.LineBasicMaterial({
    color: 0xff00f0,
});

var geometry = new THREE.Geometry();
var splinePoints = spline.getPoints(numPoints);

for (var i = 0; i < splinePoints.length; i++) {
    geometry.vertices.push(splinePoints[i]);
}

line = new THREE.Line(geometry, material);
line.position.set(0, 0, 0);
scene.add(line);
var counter = 0;

if (counter <= 1) {
    camera.position.copy( spline.getPointAt(counter) );
    tangent = spline.getTangentAt(counter).normalize();
    axis.crossVectors(up, tangent).normalize();
    var radians = Math.acos(up.dot(tangent));
    camera.quaternion.setFromAxisAngle(axis, radians);
    counter += 0.005
} else {
    counter = 0;
}

Thanks.

Answer 1

The following example shows how to create a camera that follows a spline curve. Just click on the button "Camera Spline Animation View" to see the effect. Maybe you can use the underlying code to solve your problem.