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Capsule primitive collision geometry


    The collisionCapsule object is a capsule primitive collision geometry defined by a radius and length. The central line segment of the capsule aligns with its z-axis. The origin of the body-fixed frame is at the midpoint of the central line segment of the capsule.




    CAPS = collisionCapsule(radius,length) creates a capsule primitive with the specified radius radius and length length. The radius and length arguments set the Radius and Length properties, respectively


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    Radius of the spherical ends of the capsule, specified as a nonnegative scalar. Units are in meters.

    Example: 2.5

    Length of the central line segment of the capsule, specified as a nonnegative scalar. Units are in meters.


    This is not the length from end-to-end of the capsule. The total length of the capsule is Length+2(Radius).

    Example: 4.5

    Pose of the capsule relative to the world frame, specified as a 4-by-4 homogeneous transformation matrix. Units are in meters.

    Example: trvec2tform([4 2 5])

    Object Functions

    checkCollisionCheck if two geometries are in collision
    convertToCollisionMeshConvert collision primitive geometry into collision mesh geometry
    genspheresGenerate spheres along central line segment of capsule
    showShow collision geometry


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    Create a collision capsule with a radius of 2 and length of 10. Visualize the capsule.

    cCapsule = collisionCapsule(2,10);
    [~,p] = show(cCapsule);

    Generate spheres at ratios 0.0, 0.5, and 1.0 of the capsule length.

    spheres = genspheres(cCapsule,linspace(0,1,3));

    Display the positions of the spheres.

    for i = 1:length(spheres)
         0     0    -5
         0     0     0
         0     0     5

    Set the face and edge alphas of the capsule to low values. This ensures that both the spheres are visible when you add them to the figure.

    p.FaceAlpha = 0.4;
    p.EdgeAlpha = 0.01;
    hold on

    Display the generated spheres on the capsule.


    Figure contains an axes object. The axes object contains 4 objects of type patch.

    Extended Capabilities

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

    Version History

    Introduced in R2022b