Normals\Orient Normals With Fast Marching

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This tool is accessible via the 'Edit > Normals > Orient normals > with Fast Marching' menu.

Description

This method attempts to re-orient all the normals of a cloud in a consistent way. It starts from a random point then propagates the normal orientation from one neighbor to the other.

The propagation is done with the Fast Marching algorithm applied to a grid. In practical this grid is the cloud octree considered as a given level of subdivision. Therefore the user must specify this level of subdivision. The problem is to find the right level: if the cells are too big (i.e. low level of subdivision), the propagation is not very accurate. However if the cells are too small (i.e. high level of subdivision) empty cells might appear and the propagation in one sweep won't be possible.

Warning: this method is very fast but very approximate. It is highly advised to use the Orient normals with Minimum Spanning Tree method instead.