No. The sentence of the parent post "a pixelwise error can be computed and backpropagated to the CNN" is possible only if the renderer is differentiable.
Update:
It would require more training cycles and would not be as "atomic" as iterative tweaks but seems possible.
At same time, I wonder about making loss function talk with some external renderer would make it possible to mix both approaches.
I suppose you theoretically could do it with some trial and error method or grid search or something like that, but it's going to be absolutely computationally unfeasible in the general case; the pixelwise errors only become practically useful if you have an uninterrupted differentiable/'backpropagatable' path from your parameters to the pixels.