Photogrammetry 3D Scanning

I've overcome my problems with flipped normals in Meshlab. I will upload a small programm to correct the normals in the ply files in the next days, until then I will complete the tutorial.

I've been moving to a new apartment this week and therefore the progress is a bit slow. Besides that I tried a quick scan of my former bathroom.

Source:[Alexander Kroth]

The picture shows the output of CMVS, therefore the dense point cloud. It's visible that only edges are recognized and walls or other low texture surfaces create nearly no points. The initial photo set is a series of 116 photos with a resolution of 3008x2000. The room wasn't lit very well and therefore the single images had even less feature points.

Source:[Alexander Kroth]

On the right you can see the tiles on the wall, that should be flat, but due to the low amount of points in the center of the tiles they tend to be shaped like above. The shiny edge of the bath tub couldn't be captured at all and there is a hole inside the wall in the resulting mesh. Overall the mesh quality is quite low and the mesh fits the reality poorly. For a better scan additional indirect lightning would have been necessary to capture fine details on the wall and on the tiles.

I'm currently struggling to find a good workflow to create the normals for the mesh in Meshlab, but it mostly ends in try and error... Maybe on friday I will continue the project. Until then I will collect some sample datasets that can be tested with the tutorial and compared against the results of other users.

As the tutorial is growing I'd be happy with some feedback to further improve the tutorial and to cover areas I didn't mention enough.

I've been working with 3D printers and 3D scanners for over two years now and wanted to share my knowledge about photogrammetry. The contents shown here are also part of a course I give at our local hackerspace in Darmstadt, the Makerspace Darmstadt. The photos in this tutorial where taken in the Felsenmeer:

Source:[http://www.felsenmeer-odenwald.de]

Roughly translated Felsenmeer means oceans of stones which is quite fitting if you've been there.