findPointsInCylinder

Find points within a cylindrical region in a point cloud

Since R2023a

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Syntax

indices = findPointsInCylinder(ptCloud,radius)
indices = findPointsInCylinder(___,Name=Value)

Description

indices = findPointsInCylinder(ptCloud,radius) finds the points within a cylindrical neighborhood of the specified radius in a point cloud, ptCloud.

example

indices = findPointsInCylinder(___,Name=Value) specifies options using one or more name-value arguments in addition to the previous syntax. For example, Height=10, sets the height of the cylinder to 10.

Examples

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Open Live Script

Load a point cloud from a saved MAT file. 

load("drivingLidarPoints.mat","ptCloud")

Specify a hollow cylindrical neighborhood with an inner radius of 2 meters and an outer radius of 15 meters, and find the points in the point cloud within the neighborhood.

minRadius = 2;
maxRadius = 15;

indices = findPointsInCylinder(ptCloud,[minRadius maxRadius]);

Select the cylindrical neighborhood in the point cloud, preserving the organized format.

ptCloudCylinder = select(ptCloud,indices,OutputSize="full");

Visualize the selected points.

figure
pcshow(ptCloudCylinder)

Figure contains an axes object. The axes object contains an object of type scatter.

Open Live Script

Load a point cloud from a saved MAT file. 

load("object3d.mat","ptCloud")
maxRadius = 0.1;
cylinderHeight = 0.5;

Offset the center of the cylinder 0.6 units in the X-direction and 0.2 units in the Z-direction. Then, find and select the points of the point cloud within the cylinder. 

shiftedCenter = [0.6 0 0.2];
indices = findPointsInCylinder(ptCloud,maxRadius,Height=cylinderHeight,Center=shiftedCenter,VerticalAxis="Z");
ptCloudCylinder = select(ptCloud,indices);

Visualize the selected points.

figure
pcshow(ptCloudCylinder)

Figure contains an axes object. The axes object contains an object of type scatter.

Input Arguments

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Point cloud, specified as a pointCloud object.

Cylinder radius, specified as a scalar or a 2-element vector of the form [minRadius maxRadius] that specifies the inner and outer radii of the cylindrical neighborhood. The function finds the neighbors within the specified radius around a query point in the input point cloud.

Name-Value Arguments

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Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: Height=10 sets the height of the cylinder to 10.

Height of cylinder, specified as a positive scalar.

Center of the cylinder, specified as a 3-element vector of the form [x y z] in Cartesian coordinates. The center point is halfway between the top and bottom of the cylinder, and the axis of the cylinder passes through it.

Cylinder positioned in a point cloud with the cylinder center point labeled.

Vertical axis of the cylinder, specified as "X", "Y", or "Z".

Output Arguments

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Logical indices of the points within a cylindrical neighborhood, returned as a column vector for unorganized point clouds or a matrix for organized point clouds. For organized point clouds. indices is the same size as the input point cloud, and each element with a value of 1 (true) indicates that the corresponding index of the input point cloud references a point inside the specified cylindrical neighborhood.

Extended Capabilities

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Version History

Introduced in R2023a

See Also

Functions

Objects