Hello,
I am wondering exactly how the volumetric calculation tool works. From reading the Wiki page, it appears that is uses its step^2 multiplied by the distance in whichever direction you are working with. Is the step creating a cylinder that the tool uses to find distance changes along for example, the X plane?
Thank you,
CS
Volumetric tool
Re: Volumetric tool
Well, we could say indeed that the tool is implicitly using infinite cylinders with square sections.
In effect, the points of both clouds are projected into the same 2D grid structure (with cells of size 'step'). And for each cloud, we average the height of the points falling inside each cell (it's the 'rasterization' process - one can also take the minimum or maximum height). Eventually we compute the difference of height for each cell, that we multiply by the cell surface (step^2). It only works for cells where points of both clouds have been projected inside. The others are marked as 'empty' cells and are ignored (a warning message appears if too many empty cells appear in-between other cells, which means that the cell size is probably too small compared to the clouds density).
In effect, the points of both clouds are projected into the same 2D grid structure (with cells of size 'step'). And for each cloud, we average the height of the points falling inside each cell (it's the 'rasterization' process - one can also take the minimum or maximum height). Eventually we compute the difference of height for each cell, that we multiply by the cell surface (step^2). It only works for cells where points of both clouds have been projected inside. The others are marked as 'empty' cells and are ignored (a warning message appears if too many empty cells appear in-between other cells, which means that the cell size is probably too small compared to the clouds density).
Daniel, CloudCompare admin