MATLAB 3D物体等长外轮廓生成程序

以下是使用MATLAB编写的为三维物体增加等长外轮廓的示例程序：

% 创建一个三维物体（立方体）
vertices = [0 0 0; 1 0 0; 1 1 0; 0 1 0; 0 0 1; 1 0 1; 1 1 1; 0 1 1];
faces = [1 2 3 4; 5 6 7 8; 1 2 6 5; 2 3 7 6; 3 4 8 7; 4 1 5 8];
patch('Faces', faces, 'Vertices', vertices, 'FaceColor', 'red', 'EdgeColor', 'none', 'FaceAlpha', 0.5);

% 提取物体的边界点
boundaryPoints = [];
for i = 1:size(faces, 1)
    boundaryPoints = [boundaryPoints; vertices(faces(i, :), :)];
end

% 计算边界点的凸包
k = convhull(boundaryPoints(:, 1), boundaryPoints(:, 2), boundaryPoints(:, 3));
convexHullPoints = boundaryPoints(k, :);

% 计算每两个相邻点之间的距离
distances = sqrt(sum(diff(convexHullPoints, 1).^2, 2));

% 计算等长外轮廓点的坐标
numPoints = 100; % 等长外轮廓点的数量
totalDistance = sum(distances);
stepSize = totalDistance / numPoints;
contourPoints = [];
currentDistance = 0;
for i = 1:size(convexHullPoints, 1)-1
    segmentLength = vecnorm(convexHullPoints(i+1, :) - convexHullPoints(i, :));
    while currentDistance + segmentLength >= stepSize
        t = (stepSize - currentDistance) / segmentLength;
        point = convexHullPoints(i, :) + t * (convexHullPoints(i+1, :) - convexHullPoints(i, :));
        contourPoints = [contourPoints; point];
        segmentLength = segmentLength - (stepSize - currentDistance);
        currentDistance = 0;
    end
    currentDistance = currentDistance + segmentLength;
end

% 绘制等长外轮廓点
hold on;
plot3(contourPoints(:, 1), contourPoints(:, 2), contourPoints(:, 3), 'bo');
hold off;

% 设置坐标轴
axis equal;

这个程序首先创建一个立方体作为三维物体，并使用patch函数绘制出来。然后，它提取物体的边界点并计算边界点的凸包。接下来，它计算凸包上相邻点之间的距离，并根据设定的等长步长计算等长外轮廓点的坐标。最后，它使用plot3函数将等长外轮廓点绘制出来，并设置坐标轴为等比例显示。