Mesh enhancement and densification
Polycount alone is never a good heuristic to understand the quality of a 3D reconstruction. However, there are some specific workflows where it is necessary to obtain very dense mesh (we are talking hunderd millions of polygons) in order to generate displacement maps or for similar post processing techniques. If you are wondering why you may need such a high polygon count, then you most likely do not need this feature and can happily skip this paragraph.
Since 3DF Zephyr 4.0, a new additional step after the textured mesh generation, called “Generate and export enhanced mesh” is available in the workflow > Advanced menu: this is not a photogrammetry process but rather a post processing that can lead to what is commonly known as fake detail (for example, a drawback is that tattoos gets heavily carved in human bodies as well as plain text gets carved in papers, etc).
This process is not aimed to engineering, science and survey users of 3DF Zephyr or any other field where accuracy is important. Although it is more prone to high frequency noise, this densification process to many millions (or in very niche workflows, even billions) polygon can be useful sometime.
Below a simple example from a 35 photos dataset that has been enhanced from 2 million triangles to almost 100 millions: on the left, the raw textured mesh and on the right, the enhanced textured mesh. In this case, the enhanced method wasn’t very helpful as all it did was extract more noise.
However in some cases, for example when there are a very low amount of camera that see the same point, this feature may extract “fake” detail that is actually noticeable (albeit some additional noise). This is a similar example (31 images) enhanced from 370.000 triangles (left) to 4 million triangles (right).
As a final note, the high frequency gain is not mandatory (as it is controlled by a parameter from 0% to 100%) so eventually, this feature can be used simply to densify a mesh or a textured mesh to an arbitrary polycount if desired (the other densify tool already available in Zephyr works differently and is capped to 50M points)