Lofting back 2 curves made from split tree data

HI i've been trying to loft/connect "curves' that i've made from perpendicular frames. I split the data using Split Tree component and was able to loft each sides at different sizes. But then when i tried to loft the middle section (see image 1) with the end of the bigger size frame to the beginning/start of the smaller frame i don't know how to continue.

1. tried to make them to curves then loft them but it didn't work. i presume it is because of the scrambled data.

2. tried to make them to polylines but didn't take me anywhere.

3. tried to look for rearranging the data back together so that they could possibly continue on their path to loft.

4. Tried Graft Tree component - was not able to loft as well after converting them to curve/polylines

I'm pretty sure i did something wrong. Hence i could really need some insight.

Attachments:

Rhino.PNG, 471 KB
Grasshopper.PNG, 270 KB
Lofting.gh, 17 KB

Replies to This Discussion

Permalink Reply by Joseph Oster on October 20, 2015 at 8:29am

Your "Main Points" surface param is not internalized.

I created an 'EdgeSrf' from your two "Boundary Lines"... And clearly you have two 'Lofts' that are working... Not quite obvious yet what more you want?

Connecting both of your 'Polygon' components to a single 'Loft' and setting the 'Closed' loft option is interesting. :)

Permalink Reply by Joseph Oster on October 20, 2015 at 8:50am

Hey, forget the 'Closed' loft option - just 'Reverse' the two 'Polygon' outputs and connect them to a single 'Loft' - VERY INTERESTING?

Permalink Reply by Hyungsoo Kim on October 20, 2015 at 9:35am

Hi.

Just out of curiosity, is there any special reason to do like that Instead of more simple and smooth lofting?

Permalink Reply by Joseph Oster on October 20, 2015 at 10:32am

Good question! Well done. Icons aren't easy for me though - took awhile to figure out this one ('Range'):

And where did your points come from? Did you skip his 'Field Line' component?

Is this the same thing?

Attachments:

Lofting_2015Oct20a.gh, 17 KB

Permalink Reply by Hyungsoo Kim on October 20, 2015 at 10:51am

Pretty much the same, though, fieldLine curves usually have tons of control points, so, It would be better to use rebuilded nurbs curve.

Permalink Reply by Joseph Oster on October 20, 2015 at 11:29am

I see, thank you. Any reason to use 'Divide Curve' | 'Nurbs Curve' (two components) instead of 'Rebuild Curve' (one component)?

They do appear to yield slightly different results, especially when the 'ReB' preserve tangents ('T') input is set to true instead of false.

Again, good call on the major simplification of code.

Permalink Reply by Joseph Oster on October 20, 2015 at 1:14pm

P.S. I figured out two reasons the two methods of rebuilding the curve give different results:

'Divide' has the 'N' input for "Number of segments" while 'ReB' has the 'N' input for "Number of control points" - off by one! Adding the expression "x-1" to the 'Divide|N' input fixes the 'CP' lists from the resulting curves so they are identical when 'ReB|D' = 1.
'ReB' has no default for 'D (Degree)' and when omitted, the resulting curve is segmented (D=1), not the same as the input curve from 'Field Line'. And no matter what value I use for 'D' (2, 3, 4, 5), the 'ReB' and 'Nurbs' curves never match - and the control points don't match either when 'ReB|D' != 1.

This seems odd to me? Inside baseball, I guess, but still... David?

Permalink Reply by Alli Affandi on October 20, 2015 at 2:40pm

That is amazing! and simple! I'm totally new to grasshopper. The reason i did the project like so was because i thought that was the logic behind it. Also i wanted to make the member size to be 'lofted' at 3 different sizes.

1. from center to 1/3 way to be in a uniform size.

2. the size reduces - 'loft' from bigger polygon dimension to smaller polygon dimension for the further 1/3 distance.

3. then the last 1/3 length to be in a uniform smaller polygon dimension

But simpler method is just brilliant!

Thanks

Permalink Reply by Joseph Oster on October 20, 2015 at 3:03pm

The size pattern you wanted can be done by manipulating the series of 'Radius' values coming out of the 'Range' component (the ones in the middle must repeat the same value). But I'll leave that to you or Hyungsoo Kim who had the insight to came up with this brilliant method; simpler is cool, isn't it? You did well though in using the 'Field Lines' and polygons to create a cool pattern.

Permalink Reply by Hyungsoo Kim on October 21, 2015 at 12:39am

Hi Alli.