Visual comparison of result w.r.t. GT in Open3d or Mayavi

At code to visualize the GT and the estimated sparse multiview reconstruction simultaneously, in different colors, using our visualization tools

Start by locating the existing sparse multiview reconstruction output and the project's current visualization-tool usage. Add a view that displays the ground truth and estimated reconstruction simultaneously in distinct colors, then verify that both results are visible and distinguishable.

Written by the indexing model from the issue text.