Documentation

sphereModel class

Object for storing a parametric sphere model

Syntax

model = sphereModel(params)

Description

Object for storing a parametric sphere model

Construction

model = sphereModel(params) constructs a parametric sphere model from the 1-by-4 params input vector that describes a sphere.

Input Arguments

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Sphere parameters, specified as a 1-by-4 scalar vector. This input specifies the Parameters property. The four parameters [a,b,c,d] satisfy the equation for a sphere:

${\left(x-a\right)}^{2}+{\left(y-b\right)}^{2}+{\left(z-c\right)}^{2}={d}^{2}$

Properties

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These properties are read-only.

Sphere model parameters, stored as a 1-by-4 vector. These parameters are specified by the params input argument. The four parameters [a,b,c,d] satisfy the equation for a sphere:

${\left(x-a\right)}^{2}+{\left(y-b\right)}^{2}+{\left(z-c\right)}^{2}={d}^{2}$

Center of the sphere, stored as a 1-by-3 vector [xc,yc,zc] that specifies the center coordinates of the sphere.

Radius of sphere, stored as a scalar value.

Methods

 plot Plot sphere in a figure window

Examples

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Display point cloud.

figure
pcshow(ptCloud)
xlabel('X(m)')
ylabel('Y(m)')
zlabel('Z(m)')
title('Detect a sphere in a point cloud') Set the maximum point-to-sphere distance (1cm), for sphere fitting.

maxDistance = 0.01;

Set the region of interest to constrain the search.

roi = [-inf, 0.5; 0.2, 0.4; 0.1, inf];
sampleIndices = findPointsInROI(ptCloud, roi);

Detect the globe in the point cloud and extract it.

model = pcfitsphere(ptCloud, maxDistance, 'SampleIndices', sampleIndices);

Plot the sphere.

hold on
plot(model) 