ExtrudeSurfaceTapered

Rhino Rhino for Windows
1

Greetings,

I tried to build a single-curved-surface lean outward in a constraint angle, let’s said 6 degree. I used Extrude Surface Tapered command and found it do not meet my requirement. So i tried some method, i drew different lines, one is a half circle, one is non-uniform convex, one is non-uniform S-shape-line , there is only the result for the half circle is qualified.

My analysis method is simple, i select a random point in the surface bottom edge, and link it with a perpendicular point of the top edge into a line. Then, i draw a straight line start from the initial point I selected before, in Z direction. So now i have two lines, I could calculate the angle between them. For the free form line, after the extrusion, the angles are not the same one, slightly different,

I guess it is because of the geometrical variables. If I want to have a surface which I expected, how could I make it? Is the command still not as good as we thought?

Thanks.








<a class=“attachment” href=“https://global.discourse-cdn.com/mcneel/uploads/default/15735/572d12ec292832e4.3dm”>ExtrudeCrvTapered Test.3dm (240.7 KB)

Analysis of angles.gh (14.9 KB)

2

your .3dm file didn’t upload properly… can you try uploading it again?

3

I could open it, so it’s probably your download.
EDIT: wait, indeed it had changed… I could download it earlier today.

TEST: ExtrudeCrvTapered Test.3dm
This download link seems to work :arrow_up:

-Willem

4

yep, your link works… thanks

i’ve seen this problem before in the command… as a workaround (or, just do it like this to see if it’s giving you the results you’re expecting) , try this:

ExtrudeCrvTapered doesn’t do the offsetting properly.

5

Looks like a variation of the problem which was previously reported in ExtrudeCrvTapered - bad result

6

@pascal Any estimate of when ExtrudeSrfTapared will be fixed?

7

@jeff_hammond Thanks for your suggestion, i have been trying this method and it works for me.