Manually specifying camera matrices in ThreeJS - three.js

Question

I'm working on a project where I will draw 3D graphics on a video that is filmed with a real camera. I get provided a static projection and view matrix and my task is to draw the actual graphics on top. I've got it working in pure WebGL and know I'm trying to do it in ThreeJS. The problem is that I can't find a way to manually set the projection and view matrix for the camera in ThreeJS.
I've tried to set camera.matrixAutoUpdate = false and calling camera.projectionMatrix.set(matrix) and camera.matrixWorldInverse.set(matrix), but it doesn't seam to work. It is like the actual variable isn't passed to the shader.
Does anyone know how this can be done?
This is what I've got so far:
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(
75,
window.innerWidth / window.innerHeight,
0.1,
1000
);
camera.matrixAutoUpdate = false;
camera.projectionMatrix.set(...)
camera.matrixWorldInverse.set(...)
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
var geometry = new THREE.BoxGeometry();
var material = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
var cube = new THREE.Mesh(geometry, material);
scene.add(cube);
var animate = function() {
requestAnimationFrame(animate);
renderer.render(scene, camera);
};
animate();