Thread Subject: volume under iregular point cloud

hi everyone.

I have an irregular 3D point cloud and i wish to calculate the volume under it and above aconstant Z plane.

Any ideas?

Thanks to all in advanced!

"Amit Wicnudel" <snufkinvic@yahoo.com> wrote in message <hnamjg$9q0$1@fred.mathworks.com>...
> hi everyone.
>
> I have an irregular 3D point cloud and i wish to calculate the volume under it and above aconstant Z plane.
>
> Any ideas?
>
> Thanks to all in advanced!

ok, I figured out the best way would be to use delaunay triangulation.

Now I have the triangulation from my point cloud from the line:

tri = delaunay(X,Y);

I also have a Z vector obviously.

Is there a simple way to calculate the volume now? I want to calculate the volume under the triangles and above a certain Z value.

thanks...

"Amit " <snufkinvic@yahoo.com> wrote in message <hnhcgi$t6t$1@fred.mathworks.com>...
> "Amit Wicnudel" <snufkinvic@yahoo.com> wrote in message <hnamjg$9q0$1@fred.mathworks.com>...
> > hi everyone.
> >
> > I have an irregular 3D point cloud and i wish to calculate the volume under it and above aconstant Z plane.
> >
> > Any ideas?
> >
> > Thanks to all in advanced!
>
> ok, I figured out the best way would be to use delaunay triangulation.
>
> Now I have the triangulation from my point cloud from the line:
>
> tri = delaunay(X,Y);
>
> I also have a Z vector obviously.
>
> Is there a simple way to calculate the volume now? I want to calculate the volume under the triangles and above a certain Z value.
>
> thanks...
*****************************************

got it, thanks anyway

"Amit Wicnudel" <snufkinvic@yahoo.com> wrote in message <hnamjg$9q0$1@fred.mathworks.com>...
> hi everyone.
>
> I have an irregular 3D point cloud and i wish to calculate the volume under it and above aconstant Z plane.
>
> Any ideas?
>
> Thanks to all in advanced!


First build a surface with one of this:

http://www.mathworks.com/matlabcentral/newsreader/create_message?reply_id=711429

http://www.advancedmcode.org/how-to-plot-a-coloured-surface-from-3d-scatter.html

http://www.advancedmcode.org/surface-recostruction-from-scattered-points-cloud-mycrustopen.html

http://www.advancedmcode.org/surface-recostruction-from-scattered-points-cloud-mycrust-robust.html


then compute the volume with:

http://www.advancedmcode.org/volume-enclosed-by-a-triangulated-surface.html

"Luigi Giaccari" <giaccariluigi@msn.com> wrote in message <hnocl1$9f5$1@fred.mathworks.com>...
> "Amit Wicnudel" <snufkinvic@yahoo.com> wrote in message <hnamjg$9q0$1@fred.mathworks.com>...
> > hi everyone.
> >
> > I have an irregular 3D point cloud and i wish to calculate the volume under it and above aconstant Z plane.
> >
> > Any ideas?
> >
> > Thanks to all in advanced!
>
>
> First build a surface with one of this:
>
> http://www.mathworks.com/matlabcentral/newsreader/create_message?reply_id=711429
>
> http://www.advancedmcode.org/how-to-plot-a-coloured-surface-from-3d-scatter.html
>
> http://www.advancedmcode.org/surface-recostruction-from-scattered-points-cloud-mycrustopen.html
>
> http://www.advancedmcode.org/surface-recostruction-from-scattered-points-cloud-mycrust-robust.html
>
>
> then compute the volume with:
>
> http://www.advancedmcode.org/volume-enclosed-by-a-triangulated-surface.html

Thanks.

I already managed to do that by using the delauney function and calculating the volume with my own function.

But thanks for your reply, it might come in handy later on!