intersection points and unroll split edge

Hi guys, with the script I attach here, how do I find the intersection points between curves at both surfaces and then join them into intersection lines? I want to create holes at those lines as connection for fabrication. I think it can be done by list item or cull list?? But I'm not too sure how to use that yet..

Secondly, the unroll command in rhino does not allow me to change the location where the splitting edge starts. So I want to cheat and create a teeny tiny gap to where I want the tubes to split. I guess the question is similar to the first one, how do I define the points and create the middle gap at one of the 4 sides of each tubes? I think the steps are to find the middle point of one of the sides, offset it, create lines, and delete the middle gap? All I can think of is logical steps, but I have no idea how to execute it in grasshopper!

Please help me out... Thanks!

Attachments:

20april.3dm, 46 KB
20april.ghx, 324 KB

Replies to This Discussion

Permalink Reply by Danny Boyes on April 20, 2011 at 7:45am

As a guess you have a filleted radius setting to achieve those curves, therefore you could create a circle with the same radius on the original corners. Where the circle intersect those curves is you intersection points.

Alternatively before extruding your curves to create the surfaces if you exploded them into their separate pieces i.e. lines and arcs you would get separate surfaces and would only need to find the edge curves of the surfaces.

Permalink Reply by Ruby on April 20, 2011 at 7:58am

Hi Danny,

Thanks for your input, but my next step is to distort the grids like the image below, which means that those corners will no longer form a circle. I think what I really need is the true intersection points so that however I want to distort the grids, the intersection points will correspond to it.. I have tried using CCX and BBX, but the intersection point only occurs at one corner instead of what I want above.

Permalink Reply by Ruby on April 20, 2011 at 8:04am

and also, my design intention is to focus on those corners, rather than the shape of the tubes.. I want to explore how the corners can produce various geometry by moving and controlling the coordinate points of the intersections

Permalink Reply by Danny Boyes on April 20, 2011 at 8:54am

Try the second suggestion with the exploded crvs approach.

Attachments:

20april_explodedCrvs.ghx, 365 KB

Permalink Reply by Ruby on April 20, 2011 at 9:14am

Yeap I've tried that approach.. and yes I can see the intersection points. But there are also other unnecessary points which I need to filter out before I join to the points on the bottom surface. As I distort more, the unnecessary points grow more. How should I do this? Thank you!

Permalink Reply by Chris Tietjen on April 20, 2011 at 9:06am

Here's my try at it. I couldn't get all the exploded curves to join after I created the gap. Couldn't figure that out so I created a second loft as a kludge.

Chris

Attachments:

20aprilRev1.ghx, 581 KB

Permalink Reply by Ruby on April 20, 2011 at 9:46am

Chris, this is great! is there a way to join those surfaces in gh so that when I bake into rhino, there won't be 3 separate elements in one tube?

Permalink Reply by Chris Tietjen on April 20, 2011 at 11:08am

It seems like there should be a way to join the surfaces but I'm not seeing how. It's probably a better approach to join the segments of the generating curve. I look at it again later when I get a chance.

Chris

Permalink Reply by Chris Tietjen on April 20, 2011 at 11:37am

Ruby,

This seems to do it. I created the gap before exploding the curves...this is much cleaner.

Chris

Attachments:

20aprilRev2.ghx, 423 KB

Permalink Reply by Ruby on April 22, 2011 at 9:59am

Hi Chris, Im trying to tweak this definition by using a midpoint of one of the sides instead of 'point on curve'. Attached is what I've done. It works, but the resulting curve and lofted surface created soooo many duplicates! What did I do wrong?

Attachments: