pointCloud

Object for storing 3-D point cloud

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Description

ThepointCloudobject creates point cloud data from a set of points in 3-D coordinate system The points generally represent thex,y, andzgeometric coordinates of a samples surface or an environment. Each point can also be represented with additional information, such as RGB color. The point cloud data is stored as an object with the properties listed inProperties. UseObject Functionsto retrieve, select, and remove desired points from the point cloud data.

Creation

Syntax

ptCloud = pointCloud(xyzPoints)

ptCloud = pointCloud(xyzPoints,Name,Value)

Description

ptCloud= pointCloud(xyzPoints)returns a point cloud object with coordinates specified byxyzPoints.

example

ptCloud= pointCloud(xyzPoints,Name,Value)creates apointCloudobject with properties specified as one or moreName,Valuepair arguments. For example,pointCloud(xyzPoints,'Color',[0 0 0])sets theColorproperty of the pointxyzPointsas [0 0 0]. Enclose each property name in quotes. Any unspecified properties have default values.

Input Arguments

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`xyzPoints`—3-D coordinate points
M-by-3 list of points|M-by-N-by-3 array for organized point cloud

3-D coordinate points, specified as anM-by-3 list of points or anM-by-N-by-3 array for an organized point cloud. The 3-D coordinate points specify thex,y, andzpositions of a point in the 3-D coordinate space. The first two dimensions of an organized point cloud correspond to the scanning order from sensors such as RGBD or lidar. This argument sets theLocationproperty.

Data Types:single|double

Output Arguments

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`ptCloud`— Point cloud
`pointCloud`object

Point cloud, returned as apointCloudobject with the properties listed inProperties.

Properties

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`Location`—Position of the points in 3-D coordinate space
M-by-3 array|M-by-N-by-3 array

This property is read-only.

Position of the points in 3-D coordinate space, specified as anM-by-3 orM-by-N-by-3 array. Each entry specifies thex,y, andzcoordinates of a point in the 3-D coordinate space. You cannot set this property as a name-value pair. Use thexyzPointsinput argument.

For unorganized point clouds,Locationmust be specified as anM-by-3 array, whereMis the total number of points in the point cloud.
For organized point clouds,Locationmust be specified as anM-by-N-by-3 array. The three channels represent thex,y, andzcoordinates of the points. Points obtained from a projective camera, such as Kinect^®or a lidar sensor, are stored as an organized point cloud.

Data Types:single|double

`Color`—Point cloud color
`[ ]`(default) |M-by-3 array|M-by-N-by-3 array

Point cloud color, specified as anM-by-3 orM-by-N-by-3 array. Use this property to set the color of points in point cloud. Each entry specifies the RGB color of a point in the point cloud data. Therefore, you can specify the same color for all points or a different color for each point.

The specified RGB values must lie within the range [0, 1], when you specify the data type forColorassingleordouble.
The specified RGB values must lie within the range [0, 255], when you specify the data type forColorasuint8.

Coordinates	Valid assignment of`Color`
M-by-3 array	M-by-3 array containing RGB values for each point
M-by-N-by-3 array	M-by-N-by-3 array containing RGB values for each point

Data Types:uint8

`Normal`—Surface normals
`[ ]`(default) |M-by-3 array|M-by-N-by-3 array

Surface normals, specified as aM-by-3 orM-by-N-by-3 array. Use this property to specify the normal vector with respect to each point in the point cloud. Each entry in the surface normals specifies thex,y, andzcomponent of a normal vector.

Coordinates	Surface Normals
M-by-3 array	M-by-3 array, where each row contains a corresponding normal vector.
M-by-N-by-3 array	M-by-N-by-3 array containing a 1-by-1-by-3 normal vector for each point.

Data Types:single|double

`Intensity`—Grayscale intensities
`[ ]`(default) |M-by-1 vector|M-by-Nmatrix

灰度强度每一点,指定为aM-by-1 vector orM-by-Nmatrix. The function maps each intensity value to a color value in the current colormap.

Coordinates	Intensity
M-by-3 array	M-by-1 vector, where each row contains a corresponding intensity value.
M-by-N-by-3 array	M-by-Nmatrix containing intensity value for each point.

Data Types:single|double|uint8

`Count`—Number of points
positive integer

This property is read-only.

Number of points in the point cloud, stored as a positive integer.

`XLimits`—Range ofxcoordinates
1-by-2 vector

This property is read-only.

Range of coordinates alongx-axis, stored as a 1-by-2 vector.

`YLimits`—Range ofycoordinates
1-by-2 vector

This property is read-only.

Range of coordinates alongy-axis, stored as a 1-by-2 vector.

`ZLimits`—Range ofzcoordinates
1-by-2 vector

This property is read-only.

Range of coordinates alongz-axis, stored as a 1-by-2 vector.

Object Functions

`findNearestNeighbors`	Find nearest neighbors of a point in point cloud
`findNeighborsInRadius`	Find neighbors within a radius of a point in the point cloud
`findPointsInROI`	Find points within a region of interest in the point cloud
`removeInvalidPoints`	Remove invalid points from point cloud
`select`	Select points in point cloud
`copy`	Copy array of handle objects

Examples

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Create a Point Cloud Object and Modify its Properties

Open Live Script

Read the 3-D coordinate points into the workspace.

load('xyzPoints');

Create a point cloud object from the input point coordinates.

ptCloud = pointCloud(xyzPoints);

Inspect the properties of the point cloud object.

ptCloud

ptCloud = pointCloud with properties: Location: [5184x3 single] Count: 5184 XLimits: [-3 3.4338] YLimits: [-2 2] ZLimits: [0.0016 3.1437] Color: [] Normal: [] Intensity: []

Display the point cloud by usingpcshow.

pcshow(ptCloud)

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

Modify Color of Point Cloud Data

Create an RGB color array of size same as the size of the point cloud data. Set the point colors to Red.

cmatrix = ones(size(ptCloud.Location)).*[1 0 0];

Create the point cloud object with the color property set to the RGB color array.

ptCloud = pointCloud(xyzPoints,'Color',cmatrix); pcshow(ptCloud)

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

Add Surface Normals to Point Cloud Data

Compute surface normals corresponding to the point cloud data usingpcnormals.

normals = pcnormals(ptCloud);

Create point cloud object from input point coordinates. Add the computed surface normals to point cloud object.

ptCloud = pointCloud(xyzPoints,'Normal',normals);

Display the point cloud and plot the surface normals.

pcshow(ptCloud) x = ptCloud.Location(:,1); y = ptCloud.Location(:,2); z = ptCloud.Location(:,3); u = normals(:,1); v = normals(:,2); w = normals(:,3); holdonquiver3(x,y,z,u,v,w); holdoff

Figure contains an axes object. The axes object contains 2 objects of type scatter, quiver.

Tips

ThepointCloudobject is ahandle对象。如果你想创建一个单独的副本point cloud, you can use the MATLAB^®copymethod.

ptCloudB=copy(ptCloudA)

If you want to preserve a single copy of a point cloud, which can be modified by point cloud functions, use the same point cloud variable name for the input and output.

ptCloud=pcFunction(ptCloud)

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Usage notes and limitations:

GPU code generation for variable input sizes is not optimized. Consider using constant size inputs for an optimized code generation.
GPU code generation supports the'Color','Normal', and'Intensity'name-value pairs.
GPU code generation supports thefindNearestNeighbors,findNeighborsInRadius,findPointsInROI,removeInvalidPoints, andselectmethods.
For very large inputs, the memory requirements of the algorithm may exceed the GPU device limits. In such cases, consider reducing the input size to proceed with code generation.

pointCloud

Description

Creation

Syntax

Description

Input Arguments

`xyzPoints`—3-D coordinate points
M-by-3 list of points|M-by-N-by-3 array for organized point cloud

Output Arguments

`ptCloud`— Point cloud
`pointCloud`object

Properties

`Location`—Position of the points in 3-D coordinate space
M-by-3 array|M-by-N-by-3 array

`Color`—Point cloud color
`[ ]`(default) |M-by-3 array|M-by-N-by-3 array

`Normal`—Surface normals
`[ ]`(default) |M-by-3 array|M-by-N-by-3 array

`Intensity`—Grayscale intensities
`[ ]`(default) |M-by-1 vector|M-by-Nmatrix

`Count`—Number of points
positive integer

`XLimits`—Range ofxcoordinates
1-by-2 vector

`YLimits`—Range ofycoordinates
1-by-2 vector

`ZLimits`—Range ofzcoordinates
1-by-2 vector

Object Functions

Examples

Create a Point Cloud Object and Modify its Properties

Tips

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

See Also

Functions

Topics

Computer Vision Toolbox Documentation

金宝app

Introducing Deep Learning with MATLAB

pointCloud

Description

Creation

Syntax

Description

Input Arguments

xyzPoints—3-D coordinate pointsM-by-3 list of points|M-by-N-by-3 array for organized point cloud

Output Arguments

ptCloud— Point cloudpointCloudobject

Properties

Location—Position of the points in 3-D coordinate spaceM-by-3 array|M-by-N-by-3 array

Color—Point cloud color[ ](default) |M-by-3 array|M-by-N-by-3 array

Normal—Surface normals[ ](default) |M-by-3 array|M-by-N-by-3 array

Intensity—Grayscale intensities[ ](default) |M-by-1 vector|M-by-Nmatrix

Count—Number of pointspositive integer

XLimits—Range ofxcoordinates1-by-2 vector

YLimits—Range ofycoordinates1-by-2 vector

ZLimits—Range ofzcoordinates1-by-2 vector

Object Functions

Examples

Create a Point Cloud Object and Modify its Properties

Tips

Extended Capabilities

C/C++ Code GenerationGenerate C and C++ code using MATLAB® Coder™.

GPU Code GenerationGenerate CUDA® code for NVIDIA® GPUs using GPU Coder™.

See Also

Functions

Topics

Computer Vision Toolbox Documentation

金宝app

Introducing Deep Learning with MATLAB

`xyzPoints`—3-D coordinate points
M-by-3 list of points|M-by-N-by-3 array for organized point cloud

`ptCloud`— Point cloud
`pointCloud`object

`Location`—Position of the points in 3-D coordinate space
M-by-3 array|M-by-N-by-3 array

`Color`—Point cloud color
`[ ]`(default) |M-by-3 array|M-by-N-by-3 array

`Normal`—Surface normals
`[ ]`(default) |M-by-3 array|M-by-N-by-3 array

`Intensity`—Grayscale intensities
`[ ]`(default) |M-by-1 vector|M-by-Nmatrix

`Count`—Number of points
positive integer

`XLimits`—Range ofxcoordinates
1-by-2 vector

`YLimits`—Range ofycoordinates
1-by-2 vector

`ZLimits`—Range ofzcoordinates
1-by-2 vector

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.