# Create a volume from a tube point cloud

Hello,

I have a point cloud of a curved tube, the tube has a external surface and inner surface, and a certain thickness.

I would like to create the closed volume of the tube that I can export in a STL file.

Different questions

• how can I warp a surface on the outer surface of the curved tube ?
• same for the inner surface, which is not complete. Can I reduce the outer surface to fit onto the existing points of the inner surface?

Enclosed the point cloud.

Yannick
Tube.txt (2.3 MB)

Hi Yannick - it looks like your object is awkwardly placed relative to Rhino’s world space but not complicated - do you know anything about it other than the point scan? Radius, thickness?

-Pascal

Hi Pascal,

Yes, the outer diameter is 269.5 mm and the inner diameter is 208 mm.
Both are constant over the whole tube.

Thanks’!
Yannick

Hi Yannick - the part looks like a section of a torus, most likely, so if you know say, the outer diameter of that torus - looks like about 644 mm, then you’re basically done…

-Pascal

Hi Pascal,

It’s correct. I see that I can create a torus along a curve (by defining the start and end diameter).
So I ‘just’ have to create a curve passing through the center of the torus, and then I will have the outer and inner diameters.

But how can extract the central torus curve?
Or did you have another approach in mind?

Thanks’
Yannick

Artec Studio can create CAD objects from scan data.

Hi Yannick - I think in Rhino you will need to carefully ‘eyeball’ where the central plane of the torus is - then you can look at the points in plan and make a reasaonable guess (Circle > 3Points, or Circle>FitToPoints for example with Point Osnap and Project on) to get the outer circle of the torus. That is what I did anyway…

-Pascal

Hi,

I achieved to create a volume from the torus point cloud by warping 2 surfaces (on both sides) of the torus. The problem is however, that it creates like a suture on the projection plane (see attached).

So how can I create an outer surface that exactly reflects the variation of the point cloud on the whole circumference? (warp is here not the appropriated method).

Thank you,
Yannick