This command allows to keep points regularly spaced on cloud(s).
Requirements
Select at least one cloud and launch the command.
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Set the value for Average distance. This value is used to define the size of the grid cells projected on the point cloud. In each cell, a small part of the surface is computed and the closest point to the surface is considered as the best one and is kept.
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Locally, if the density of points is not sufficient to calculate a surface, the grid spacing is increased to an optional size that can be defined by the parameter Max distance.
Notes
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If no Max distance size is set, the cells can grow to the size of the cloud itself.
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To ensure a good result, if Max distance is used, it can't be lower than twice the Average distance.
Technical information
Comparison between Reduce and Resample:
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Reduce |
Resample |
|---|---|---|
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Reduction factor (ratio between the number of input points and output points) |
The reduction factor is "under control" and can be low. |
The reduction factor is not known in advance. |
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Noise measurement elimination |
No measurement noise removal. Points in low density areas are all preserved unlike the high density areas where points are primarily destroyed. |
If a maximum distance is fixed, the points in low density areas are destroyed, because they are suspected of being noisy points. |
|
Point selection |
No point is "qualified". The processing is purely statistical. |
Each point is singly "qualified" to keep only the best ones. |