🔷Index Select Point Cloud

Function Description

This operator is used to select one or more point clouds from an input point cloud list (a data collection containing multiple point clouds) based on specified index numbers. Users can precisely select a specific point cloud from the list by setting index numbers, or retain all point clouds except those with specified index numbers through the reverse index function.

Usage Scenarios

  • Processing Multi-Point Cloud Input： When the previous operator (such as point cloud clustering, multi-template matching) outputs a list containing multiple point clouds, this operator can be used to select a specific point cloud from it for subsequent processing. For example, select the first point cloud cluster or the last point cloud cluster from clustering results.

  • Filter Specific Point Clouds： When it’s necessary to exclude a specific point cloud from the list, the reverse index function can be used. For example, remove the result point cloud with the lowest or highest matching score.

  • Process Control： In complex algorithm workflows, conditionally select a specific point cloud from the list for processing.

Input Output

Input

Point Cloud: A list containing one or more point clouds.

GetPointsValueByIndex input

Output

Indexed Point Cloud List: List containing selected point clouds.

GetPointsValueByIndex output

Parameter Description

This operator has two versions:

  • Index Select Point Cloud : Processes point clouds without normal information.

  • Index Select Point Cloud (with Normals) : Processes point clouds with normal information.

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

  • Index Starts from 0： The first point cloud in the list has index 0, the second has index 1, and so on.

  • -1 Index： -1 is a convenient shortcut for selecting the last element in the list without needing to know the exact length of the list beforehand.

  • Index Range： Ensure that the set "Index Number" is within the valid range of the input point cloud list, otherwise an error will occur.

Index Number

Parameter Description

Specifies the position number of the point cloud to be selected (or excluded in reverse index) in the input list. Index counting starts from 0. The special value -1 represents the last point cloud in the list.

Parameter Adjustment

  • Set to 0: Select the 1st point cloud in the list.

  • Set to 1: Select the 2nd point cloud in the list.

  • Set to -1: Select the last point cloud in the list.

  • Set to other positive integer n: Select the (n+1)th point cloud in the list.

  • Note : The set index number must be within the valid range (from -1 to list length-1), otherwise the operator will report an error. For example, if the input list has only 3 point clouds, the valid index range is -1, 0, 1, 2.

Parameter Range

[-1, 10000], Default: 0, actual effective upper limit depends on input list length.

GetPointsValueByIndex output

GetPointsValueByIndex 1

GetPointsValueByIndex 2

GetPointsValueByIndex 3

Index Number=0

Index Number=1

Index Number=2

Index Number=3

Reverse Index

Parameter Description

Changes the operator’s selection logic.

Parameter Adjustment

  • Disable (Default) ：Forward indexing, the operator only outputs the point cloud specified by the "Index Number" parameter, the output list contains only one point cloud.

  • Enable： The operator outputs all point clouds in the list except the one specified by the "Index Number" parameter, the output list contains the original list length minus one point clouds.