1. A computer implemented method, comprising: constructing, by one or more computing device, a slanted voxel grid oriented in a direction between at least two camera locations; projecting, by the one or more computing devices, images from respective camera locations onto the constructed voxel grid; calculating, by the one or more computing devices, for one or more voxels in the voxel grid, a photo-consistency error between the projected images at a center of each of the one or more voxels, the photo-consistency error being calculated as a magnitude of a gradient difference of the projected images at the center of each respective voxel of the one or more voxels; and computing, by the one or more computing devices, a three dimensional surface passing through voxel locations corresponding to one or more calculated gradient difference values of the one or more voxels, wherein the voxel locations are located at the center of each respective voxel of the one or more voxels.