If you only want to reconstruct the content in the input images without any imagination, Atlas can do sparse 3D reconstruction where it predicts a depth map for each input pixel, without predicting anything occluded or not visible in the input views. This could be used to implement your "fog of war" view.
But sometimes you want the model to stitch together views and imagine a coherent completion; this is a powerful tool for building and authoring generative worlds. For example the 1 minute video we show in the post was built by positioning seven unrelated input images in space and prompting the model to interpolate between them along a hand-specified camera path.