What algorithm(s) are behind Google Street View's 3d mapping mode?
Google said how in 2012, avoiding explaining too many details

The never-ending quest for the perfect map


  ...new imagery rendering techniques and computer vision that let us
  automatically create 3D cityscapes, complete with buildings, terrain
  and even landscaping, from 45-degree aerial imagery


and here it's a video of the feature.

So we know that "Computer Vision" is used. I guess the edges are detected, along with the shadows, to build the elevation of the object. Then the segmented image is used as a texture on the built mesh.

However, i saw this paper linked, and i think a similar technique is used in Google to extract the 3d mesh from different 45° images.

There are a lot of papers (a book too) about "building extraction/detection".


Detection of buildings in urban and suburban areas using very high resolution satellite
Google Scholar: Building Detection
Google Scholar: Building Detection from Satellite Images


src: How does the new google maps make buildings and cityscapes 3D?