Editing a grid so it will start the weave at a single height

Hello everyone!

I am working on a model with a woven structure.

At the edges the weave starts at different heights (as shown in the picture). I want it to connect to a single edge line, that is why It is essential they start in the same height.

The woven structure goes in 2 directions so there is 4 edges that would need editing.

I feel like I would have to shift the grid in a certain way but Im not sure how to do this because the place where the weaves are at the same height is variable.

Thanks for your input in advance.

Attachments:

Capture.PNG, 46 KB
hypparschaal 16 (met doorsneden).gh, 35 KB

Replies to This Discussion

Permalink Reply by Daniel on March 20, 2017 at 8:21am

Ooh that's a nice tool, i get it!

Permalink Reply by Joseph Oster on March 20, 2017 at 9:21am

Here is a version that uses your offset surface idea. It weaves, then culls alternate points from the two surfaces to create the guide curves. Flipping the points generates the second set of curves. Finally, a cluster I just wrote called 'zEnds', in the pink(?) group, replaces the first and last weaved points on each curve with the relevant points from the original surface.

Code inside the 'zEnds' cluster:

I like these curves a lot! They work well on all three test surfaces. Better and much simpler than the curves I created yesterday, which I discarded.

Both of our versions of the ribbons need improvement.

I encapsulated code I had in the blue groups to a cluster called 'RemFL'. It removes first and last items in any list. You can see it in my version of the ribbons. I tried applying it to your version of ribbons but had trouble merging them in sequence so skipped it.

Attachments:

weave_2017Mar20a.gh, 66 KB

Permalink Reply by Daniel on March 20, 2017 at 10:23am

Hey again! You are putting a lot of work in this, thank you very much!

But in the last version to me it looks like the weave is not right anymore? The ribbons are intersecting instead of weavng over eachother.

Permalink Reply by Joseph Oster on March 20, 2017 at 11:14am

Yikes! Missed that. Resurrected some code to shift the cull pattern on alternate rows.

Don't worry, I'll stop when it isn't fun anymore.

Attachments:

weave_2017Mar20b.gh, 73 KB

Permalink Reply by Joseph Oster on March 20, 2017 at 11:26am

Centering the ribbons on the guide curve would be better... Simple on my version by just moving the origin for the ribbon base rectangle by x/-2:

Will try to fix alignment of the sweep sections eventually, unless you beat me to it.

Attachments:

weave_2017Mar20c.gh, 72 KB

Permalink Reply by Daniel on March 20, 2017 at 11:58am

Awesome!

I have the feeling the ribbons do not have the right angle because the "Align" component gets an angle that corresponds to a frame that is in a normal with the plane. Instead it should be getting the angle from a plane that is perpendicular through the plane?

Right now I'm ttrying to find out if Im correct in this.

Attachments:

Capture.PNG, 104 KB

Permalink Reply by Joseph Oster on March 20, 2017 at 12:32pm

Well, well... I figured out why my ribbons are messed up! I greatly simplified my code to align the rectangular sections for 'Sweep1' - just as trivial as I expected; surface normals have nothing to due with it. It works perfectly on the 'PlaneSrf', near perfectly on your slightly curved test surface ('Original Srf' in the GH file) and fails badly on the cylinder - UNLESS I bypass 'zEnds'. BIG CLUE!

Using the 'Tree/List Viewer' (not just for beginners, I use it all the time!), I finally figured out why. It turns out that on curved surfaces, the point on the original surface is not in a straight line with the corresponding points on the offset surfaces. Using it causes the guide curve to twist, which causes torsion that messes up alignment of the 'PFrames'.

So (without trying to figure out why they don't line up...?), the fix is to derive the point half way between the two and use that as the substitute end point. That was the main purpose of this thread, after all, eh?

I want it to connect to a single edge line

TBC (To Be Continued), as time permits.

Permalink Reply by Daniel on March 21, 2017 at 4:29am

I just adjusted the perp frames to only be present at the end and the beginning (by setting N to 1), this improved the torsion in the sections!

Permalink Reply by Daniel on March 21, 2017 at 4:40am

I did find another weird thing in the front view. For some reason the weaves in the edges are not in the middle of the weave. This is even worse when the weaves are connecting in he edge.