Using the main camera, by measuring the focus at different points (scanning in a grid of the desired output resolution), it should be possible to acquire the data for generating an approximate depth map of the scene (obviouslly only inside the range of focus that can be measured)


If any points can't have its focus measured at any exposure, interpolate the value from the surrounding poihts.


Ideally, besides the depth map, also capture a visible image of the scene (even better if you make it have superfocus, compositing the best focus for each section together into a final image where everything is in focus)



I know the depth map will not have anywhere near professional grade depth resolution and precision, but even just an aproximate rough map will already be awesome.