🔷Connected Component Segmentation

Function Description

This operator performs clustering segmentation on the input point cloud. It combines spatially close enough points into independent point cloud clusters. If the distance between two points is less than the set "connectivity distance threshold", they are considered to belong to the same connected component (i.e., the same cluster). Finally, it outputs a point cloud list where each point cloud represents a segmented cluster.

Usage Scenarios

  • Instance Segmentation: Segment mutually separated objects in a scene into independent point cloud clusters.

  • Noise Removal: Can filter out point cloud clusters with too few points that are likely noise.

  • Point Cloud Preprocessing: Before performing tasks like target recognition and pose estimation, segment the original point cloud into meaningful units to simplify subsequent processing.

Input Output

Input

Point cloud: Input point cloud or point cloud list.

ConnectedComponentSegmention input

Output

Segmented point cloud: List of point clouds obtained after segmentation, where each element is a segmented point cloud cluster.

ConnectedComponentSegmention output

Parameter Description

This operator has two versions:

  • Connected Component Segmentation: Processes point clouds without normal information.

  • Connected Component Segmentation (with Normals): Processes point clouds with normal information.

Both have identical functionality and parameters, differing only in the type of point cloud data processed.

The output can handle single point clouds or point cloud lists. If it’s a list, each point cloud in the list will be segmented independently, and then all results will be merged for output (according to sorting and retention parameters).

Connectivity Distance Threshold

Parameter Description

Defines the maximum distance at which points are considered "connected". If the distance between two points is greater than this threshold, they definitely do not belong to the same clustering cluster.

Parameter Adjustment

  • Decreasing the threshold: Will cause the point cloud to be segmented more finely, possibly splitting the same object into multiple small clusters, or making it easier to separate closely positioned objects.

  • Increasing the threshold: Will make point cloud clusters larger, possibly merging different nearby objects into one cluster.

Parameter Range

[0.0001, 1000], default: 10

ConnectedComponentSegmention output

ConnectedComponentSegmention 1

ConnectedComponentSegmention 2

Connectivity distance threshold=10

Connectivity distance threshold=15

Connectivity distance threshold=30

Minimum Cluster Point Count

Parameter Description

The minimum number of points that a valid clustering cluster must contain.

Parameter Adjustment

Used to filter out small point cloud clusters, which are usually noise or incomplete object parts. Increasing this value can remove more small clusters (noise), but if set too large, it may filter out effectively small valid objects.

Parameter Range

[1, 4000000], default: 100

ConnectedComponentSegmention 3

ConnectedComponentSegmention output

ConnectedComponentSegmention 4

Minimum cluster point count=50

Minimum cluster point count=100

Minimum cluster point count=300

Maximum Cluster Point Count

Parameter Description

The maximum number of points that a valid clustering cluster is allowed to contain.

Parameter Adjustment

Used to filter out overly large point cloud clusters. This may be useful in certain scenarios, for example, when background or ground is incorrectly clustered into a very large cluster, it can be removed through this parameter. Usually keep the default value (a very large number), unless there is a clear need to filter out extremely large point cloud clusters.

Parameter Range

[1, 4000000], default: 4000000

ConnectedComponentSegmention 5

ConnectedComponentSegmention 6

ConnectedComponentSegmention 7

Maximum cluster point count=1000

Maximum cluster point count=10000

Maximum cluster point count=100000

Enable Sorting

Parameter Description

Determines whether to sort the final output point cloud cluster list by point count from large to small.

Parameter Adjustment

Enable (default): Output point cloud list is sorted by point count from most to least.

ConnectedComponentSegmention output

Disable: Output point cloud list order is indeterminate.

ConnectedComponentSegmention 8

If subsequent processing depends on the size order of point cloud clusters (e.g., always processing the largest cluster), this should remain enabled.

Retain All Results

Parameter Description

Determines whether to output all clustering results that meet size conditions.

Parameter Adjustment

  • Enable (default): Retain all clustering clusters that pass minimum/maximum point count filtering.

  • Disable: Only retain the top N clustering clusters with the most points, where N is specified by the "Retain Result Count" parameter below.

Enable Node

Parameter Description

Controls whether this operator executes clustering operations.

Parameter Adjustment

  • Enable (default): The operator executes clustering functionality normally.

  • Disable: The operator performs no operations.