Not able to understand the concept for making normal

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Permalink Reply by Joseph Oster on March 18, 2017 at 12:03am

Looks like you sorta got the idea but...  Why loft the 'A1' and 'A2' curves separately (two surfaces) instead of using the combined 'B' curve to get a single surface?

Did you notice, by their color and the fact that one pipe goes out and one goes in, that the surface normal direction is opposite for the two surfaces?  Based on an earlier thread, you should know why by now.  The two curves have opposite directions (again!); see the white arrows using Rhino 'Analyze | Direction'?

As before, you can fix that by flipping one curve to match the other.  HOWEVER, you connected your curves directly to the 'Divide' components instead of using 'Crv' geometry params - bad form.  And as before, you "fixed it" by reversing the list of starting points ('S' input to 'BiArc').  Better like this - 'Crv' params are internalized, no need for Rhino file:

Well, well!  That didn't fix the opposite surface normals after all!  Trust me, though, using geometry params and being conscious about matching curve directions is "best practice".  But I haven't lofted 'BiArc' curves for awhile, it's late and I want to move on.  OH!  I just noticed that you reversed the 'Z' direction for one half of the 'BiArc' - that explains it:

Moving on...  You've basically got it, though I would do it differently - same result, like this:

I haven't really explained surface normal vectors - can you figure it out from here?  One more little wrinkle (Normal_2017Mar17b.gh):

Attachments:

• Normal_2017Mar17a.gh, 12 KB
• Normal_2017Mar17b.gh, 14 KB

Permalink Reply by anchal bhaskar on March 19, 2017 at 6:48pm

I got it. I am understanding the long routes I am taking and the silly mistakes I did. Thank you so much once again.

Regards,

Anchal