Using endTransform with an affine matrix?

CesiumJS
1

So far I’ve used an affine matrix in the frustum to change my rendered frame pixel wide in the method “update”.
This is an ugly hack shortcut that looks somewhat like:

if (defined(window.changeMatrix)){
var resultNewArr = ;
for (var i = 0; i < 16; i++) {
resultNewArr[i] = window.affineMatrix[i];
}
var newMatrix = Matrix4.fromArray(resultNewArr);

            Matrix4.multiply( newMatrix, frustum._perspectiveMatrix,frustum._perspectiveMatrix);
            Matrix4.multiply(newMatrix, frustum._infinitePerspective, frustum._infinitePerspective);
        }

``

(added right after line: https://github.com/AnalyticalGraphicsInc/cesium/blob/1.19/Source/Scene/PerspectiveOffCenterFrustum.js#L132).

I’ve noticed that the “endTransform” was added to the “setView” method and I thought this might be used to achieve my end goal in a “cleaner” way.

The end goal is nicely put here:

https://groups.google.com/forum/embed/?place=forum/cesium-dev&showsearch=true&showpopout=true&hideforumtitle=true&fragments=true&parenturl=http%3A%2F%2Fcesiumjs.org%2Fforum.html#!searchin/cesium-dev/affine/cesium-dev/u_lKmwrkkGE/qrrwuDGsEQAJ

Assuming I have my affine matrix the same way (as a Matrix4 newMatrix), can I use the endTransform in some way in order to achieve the same effect? Another question, which I was unable to find the answer to is, what is the relation (if any) between the camera.transform (which is the endTransform as far as I can tell from the code) and the frustum.projectionMatrix (which is what I change in the frustum.update method)?