matlab选择三维点坐标

选择三维点云的点，返回坐标： H = CLICKA3DPOINT(POINTCLOUD) shows a 3D point cloud and lets the user % select points by clicking on them. The selected point is highlighted % and its index in the point cloud will is printed on the screen. % POINTCLOUD should be a 3*N matrix, represending N 3D points. % Handle to the figure is returned. % % other functions required: % CALLBACKCLICK3DPOINT mouse click callback function % ROWNORM returns norms of each row of a matrix % % To test this function ... % pointCloud = rand(3,100)*100; % h = clickA3DPoint(pointCloud); % % now rotate or move the point cloud and try it again. % (on the figure View menu, turn the Camera Toolbar on, ...) % % To turn off the callback ... % set(h, 'WindowButtonDownFcn','');

function callbackClickA3DPoint（src eventData pointCloud）
% CALLBACKCLICK3DPOINT mouse click callback function for CLICKA3DPOINT
%
%   The transformation between the viewing frame and the point cloud frame
%   is calculated using the camera viewing direction and the ‘up‘ vector.
%   Then the point cloud is transformed into the viewing frame. Finally
%   the z coordinate in this frame is ignored and the x and y coordinates
%   of all the points are compared with the mouse click location and the 
%   closest point is selected.
%
%   Babak Taati - May 4 2005
%   revised Oct 31 2007
%   revised Jun 3 2008
%   revised May 19 2009

point = get（gca ‘CurrentPoint‘）; % mouse click position
camPos = get（gca ‘CameraPosition‘）; % camera position
camTgt = get（gca ‘CameraTarget‘）; % where the camera is pointing to

camDir = camPos - camTgt; % camera direction
camUpVect = get（gca ‘CameraUpVector‘）; % camera ‘up‘ vector

% build an orthonormal frame based on the viewing direction and the 
% up vector （the “view frame“）
zAxis = camDir/norm（camDir）;    
upAxis = camUpVect/norm（camUpVect）; 
xAxis = cross（upAxis zAxis）;
yAxis = cross（zAxis xAxis）;

rot = [xAxis; yAxis; zAxis]; % view rotation 

% the point cloud represented in the view frame
rotatedPointCloud = rot * pointCloud; 

% the clicked point represented in the view frame
rotatedPointFront = rot * point‘ ;

% find the nearest neighbour to the clicked point 
pointCloudIndex = dsearchn（rotatedPointCloud（1:2:）‘ ... 
    rotatedPointFront（1:2））;

h = findobj（gca‘Tag‘‘pt‘）; % try to find the old point
selectedPoint = pointCloud（: pointCloudIndex）; 

if isempty（h） % if it‘s the first click （i.e. no previous point to delete）
    
    % highlight the selected point
    h = plot3（selectedPoint（1:） selectedPoint（2:） ...
        selectedPoint（3:） ‘r.‘ ‘MarkerSize‘ 20）; 
    set（h‘Tag‘‘pt‘）; % set its Tag property for later use   

else % if it is not the first click

    delete（h）; % delete the previously selected point
    
    % highlight the newly selected point
    h = plot3（selectedPoint（1:） selectedPoint（2:） ...
        selectedPoint（3:） ‘r.‘ ‘MarkerSize‘ 20）;  
    set（h‘Tag‘‘pt‘）;  % set its Tag property for later use

end

fprintf（‘you clicked on point number %d\n‘ pointCloudIndex）;

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     文件        2361  2009-11-10 14:54  callbackClickA3DPoint.m
     文件        1600  2009-11-10 14:52  clickA3DPoint.m
     文件        1332  2009-11-10 15:00  license.txt
     文件         338  2009-11-10 14:51  rowNorm.m