topic Re: How to create a solid from polyines? in AutoCAD Map 3D Forum

How to create a solid from polyines?

john_daues — Thu, 09 Dec 2021 17:32:49 GMT

I need to create a solid from the polylines. Referring to the attached, the solid should have a hole in the middle (like a donut) and then tapers out to the edge.

Can some outline the steps to do this?

Thanks

Re: How to create a solid from polyines?

Alfred.NESWADBA — Thu, 09 Dec 2021 20:25:54 GMT

Hi,

you can run 3 times command _LOFT

1= from outer spline to upper circle

2= from upper circle to lower circle

3= from lower circle to outer spline

Then run command _UNION with these 3 surfaces.

At least run command _CONVTOSOLID to convert the surface to a 3D-Solid.

- alfred -

Re: How to create a solid from polyines?

pendean — Thu, 09 Dec 2021 20:28:05 GMT

Try this tip https://forums.autodesk.com/t5/autocad-forum/3d-polyline-to-solid/m-p/7995044#M932880 and explore this one https://forums.autodesk.com/t5/autocad-forum/creating-a-3d-solid-from-3d-lines/td-p/7773384

Re: How to create a solid from polyines?

john_daues — Thu, 09 Dec 2021 20:43:41 GMT

Thanks for your reply. I am following your steps but I must be doing something wrong. I do the first loft command as you specify, then I do the second. However, with this second command the hole appears to be filled in, i.e. not like a donut. (see attached)

What can you suggest?

Re: How to create a solid from polyines?

Alfred.NESWADBA — Thu, 09 Dec 2021 20:54:51 GMT

Hi,

please find this video showing the steps I'm going.
It might be helpful to have SELECTIONCYCLING activated to really know which of the selected objects are used.

- alfred -

Re: How to create a solid from polyines?

john_daues — Thu, 09 Dec 2021 22:21:22 GMT

Thanks! I have it now.

Now I use the command massprop and it shows:

---------------- SOLIDS ----------------

Mass: 1444.0888
Volume: 1444.0888

...

What are the units? I think it is cubic feet. Where do I see/set this?

Re: How to create a solid from polyines?

Alfred.NESWADBA — Thu, 09 Dec 2021 22:40:39 GMT

Hi,

>> What are the units?

This question can only be answered by yourselves as only you know which units where used to create the basic geometry. The result of _MASSPROP uses the same units used for the current objects.

- alfred -