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fitting a cylinder to point cloud of tree and then finding v

Posted: Wed Oct 15, 2014 11:19 am
by jeniasingh
Dear Sir,
I have a point cloud of tree i want to fit a cylinder to it and also after that i need to calculate it's volume. please help me how can i do it.

Re: fitting a cylinder to point cloud of tree and then findi

Posted: Wed Oct 15, 2014 11:45 am
by daniel
Hi,

the only way to fit a cylinder today in CC is to use the 'qRansacSD' plugin (SD = shape detection).

You should use the latest release (2.6.0) as this plugin dialog is much clearer now.

Once get your cylinder (be sure to uncheck all other entities!) you simply read out it's height and radius to deduce the volume.

Re: fitting a cylinder to point cloud of tree and then findi

Posted: Fri Oct 17, 2014 5:09 pm
by jeniasingh
Thank you sir for your reply.
But when I am fitting a cylinder to tree point cloud it is fitting cylinder to the whole point cloud. i want to fit a cylinder at a height of 1.37 m and then want to know it,s radius.please help.

Re: fitting a cylinder to point cloud of tree and then findi

Posted: Fri Oct 17, 2014 5:38 pm
by daniel
You could segment the cloud (with the scissors tool) so as to keep only the points on which you want to fit the cylinder?

Re: fitting a cylinder to point cloud of tree and then findi

Posted: Tue Oct 21, 2014 7:27 am
by jeniasingh
Thank you sir it helped.
how can i achieve slicing of the point cloud data at different heights like starting from 0m to 1.37m then 1.37m to 4m and so on.

Re: fitting a cylinder to point cloud of tree and then findi

Posted: Tue Oct 21, 2014 8:30 am
by daniel
You can use the 'Cross section' tool (with the 'multiple slice' generation option where you define a first section box that is repeated in one or several dimensions).

Re: fitting a cylinder to point cloud of tree and then finding v

Posted: Fri Sep 10, 2021 5:20 am
by Amaljith
Hi sir,
I have the point cloud data of a cylinder from ID side in .e57 format. I have the original diameter of the cylinder. So I want to check for any diameter changes. Is it possible in CC?
Please help if its possible. Thank you in advance.

Re: fitting a cylinder to point cloud of tree and then finding v

Posted: Sun Sep 12, 2021 9:27 pm
by daniel
Well, you can create a cylinder entity (with the right radius). And then roughly align it with you cloud (manually). And eventually align it finely with the ICP registration tool. This will give you the difference to your theoretical cylinder/radius.

Otherwise you can use the Ransac Shape Detection plugin to fit a cylinder.