This tutorial illustrates how to enhance results with strict volumetric masking feature. Applying a single mask or a few masks can be enough for this approach. 


Depth maps based mesh reconstruction method

In older versions of PhotoScan/Metashape application, polygonal mesh reconstruction required dense cloud data, and in some cases user faced the necessity to manually remove noise from the dense cloud, or to mask nearly all images before building a dense cloud. The new mesh reconstruction method uses depth maps directly without the need to generate a dense point cloud first.
Building model using the depth maps source option allows to use strict volumetric masks option in the Build Mesh dialog window.


A mesh generated based on medium quality depth maps is illustrated below. It can be seen that although the whole hand was reconstructed successfully, the white background without texture stuck between the index and middle fingers.



Strict volumetric masking

The depth maps based mesh reconstruction method with strict volumetric masking makes it possible to remove this noise with a single mask (or just with a couple of masks). 

Attention! Note that this masking is strict: each masked out pixel says to the algorithm that the ray coming from the respective camera through this pixel must pass only through the empty space. So please be careful and don't mask something important.

    

Previously to prevent sticking textureless background to model it was required to create masks for all images (at least coarse masks with a magic wand or by color). Now you don't need to create so many masks: just reconstruct the model without masks, and if there will be noisy volume, suppress it with a strict volumetric mask on the image that observes the respective part of the space. You can find useful information about model masking in our article - Masks


White background can be masked:




Note: 

  • while you are holding Ctrl scissors path will automatically go along the texture border, and thus you will have to do just a few mouse clicks to perform the task;
  • to finish selection with scissors, you can just press Esc, and the current selection path will automatically be connected with the beginning (you can click Esc one more time to remove selection).

Now model can be built, with strict volumetric masking input being considered: Workflow > Build Mesh... 


The resulting model looks fine thanks to a single mask we applied: