My data is 3d point cloud (x,y,z coordinates). By joining these points various shapes are made. I have to create a boundary (as shown in figure)within which the point distance is within a threshold i.e.'rp'. A,B and all intermediate points are data.

Answer 1

[Walter Roberson]

This might be a job for Alpha Shapes

http://www.mathworks.com/examples/matlab/1189-alpha-shapes

http://www.mathworks.com/matlabcentral/fileexchange/28851-alpha-shapes

[varun]

thanks,this is useful for me.But one more question i have,that if (a)is the intial region,and new region(c) is defined as the intersection of of the spherical region centered at point A ,spherical region centered at point B and initial region. How can i find (c).I mean to say that which output of 'alphavol' is used for intersection?? Is that S.bnd?

[Walter Roberson]

I have no idea.