findPointsInModel

Find points in or on surface of geometric model

Since R2024a

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    Syntax

    indices = findPointsInModel(model,ptCloud)

    Description

    indices = findPointsInModel(model,ptCloud) finds the points in the point cloud ptCloud that are located inside or on the surface of the geometric shape specified by model, and returns their linear indices.

    example

    Examples

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    Open Live Script

    Load a MAT file containing point cloud data into the workspace.

    load("object3d.mat")

    Visualize the point cloud.

    figure
pcshow(ptCloud)

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

    Define a region of interest (ROI) in the point cloud in which to detect a cylinder model.

    roi = [0.4 0.7; -0.1 0.2; 0 0.4];
sampleIndices = findPointsInROI(ptCloud,roi);

    Set a maximum point-to-cylinder distance of 5 mm for cylinder fitting and the orientation constraint.

    maxDistance = 0.005;
referenceVector = [0 0 1];

    Detect a cylinder in the point cloud.

     model = pcfitcylinder(ptCloud,maxDistance,referenceVector, ...
        SampleIndices=sampleIndices);

    Create a synthetic point cloud that is evenly distributed and covers the region of interest.

    gridStep = 0.005;
[x,y,z] = meshgrid(roi(1,1):gridStep:roi(1,2),roi(2,1):gridStep:roi(2,2), ...
roi(3,1):gridStep:roi(3,2));
syntheticPtCloud = pointCloud([x(:) y(:) z(:)],Color=[0.7 0.7 0.8]);

    Find the points in the synthetic point cloud that are in the cylinder.

    idx = findPointsInModel(model,syntheticPtCloud);
cylinderPtCloud = select(syntheticPtCloud,idx);

    Visualize the resulting point cloud, with the synthetic points in the cylinder modeling the object on the table.

    figure
pcshow(cylinderPtCloud)
hold on
pcshow(ptCloud)

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

    Open Live Script

    Load a MAT file containing a point cloud into the workspace.

    load("object3d.mat")

    Visualize the point cloud. 

    figure
pcshow(ptCloud)

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

    Define a region of interest (ROI) in the point cloud in which to detect a sphere model.

    roi = [0.2 0.55; 0.2 0.5; 0 0.5];
sampleIndices = findPointsInROI(ptCloud,roi);

    Set a maximum point-to-sphere distance of 5mm for sphere fitting.

    maxDistance = 0.005;

    Detect the sphere in the point cloud.

    [model,inlierIdx] = pcfitsphere(ptCloud,maxDistance,SampleIndices=sampleIndices);

    Find one of the colors in the detected sphere, to use for the synthetic point cloud.

    inlierPtCloud = select(ptCloud,inlierIdx);
color = median(inlierPtCloud.Color);

    Create a synthetic point cloud that is evenly distributed and covers the region of interest.

    gridStep = 0.005;
[x,y,z] = meshgrid(roi(1,1):gridStep:roi(1,2),roi(2,1):gridStep:roi(2,2), ...
roi(3,1):gridStep:roi(3,2));
syntheticPtCloud = pointCloud([x(:) y(:) z(:)],Color=color);

    Find the points in the synthetic point cloud that are in the sphere.

    idx = findPointsInModel(model,syntheticPtCloud);
spherePtCloud = select(syntheticPtCloud,idx);

    Visualize the resulting point cloud, with the synthetic points in the sphere modeling the object on the table.

    figure
pcshow(spherePtCloud)
hold on
pcshow(ptCloud)

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

    Input Arguments

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    Parametric model, specified as a cylinderModel or sphereModel object.

    Point cloud in the sensor coordinate system, specified as a pointCloud object.

    Output Arguments

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    Linear indices of the point cloud points that are located inside or on the surface of the model, returned as a column vector.

    Version History

    Introduced in R2024a

    See Also

    Objects