GH does not want to utilize curves for loft / messes up order

Grasshopper gives me a hard problem to solve.

I created curves via offset and move.

I selected the right order.

But Grasshopper does not want to loft them.

First image shows the third curve is skipped.

Second images shows the skipped curves later loft with

other curves which were skipped as well.

Whats going on here?

I have no idea on how to work round here.

Attachments:

Motorola PrePaid.3dm, 47 KB
Motorola PrePaid.ghx, 487 KB

Replies to This Discussion

Permalink Reply by Claas Eicke Kuhnen on February 20, 2010 at 8:46pm

I noticed that the issue is the curve offset tool.

I cannot loft between the offset without issues.

If I only loft between the raw lines or moved lines it all works fine.

Permalink Reply by Luis Fraguada on February 21, 2010 at 3:38am

Check the paths of the curves. Depending on the actions you used, they might be different, and the loft will not use them in the proper order.

Permalink Reply by to] on February 21, 2010 at 7:11am

hi class turn on fency wires and check your path's with param viewer you have as luis mentioned a path structure problem

Permalink Reply by MARIO VERGARA on February 21, 2010 at 7:20am

hi claas.
what works for me in this cases is that i conect a panel componento to the curves i want to loft, so say.
upper. 0,0,0
mid. 0,0
lower. 0,0,0
you would have to add a graft component to the mid curve to add a 0 or a branch
hope it works for you....

Permalink Reply by to] on February 21, 2010 at 7:23am

hi mario not a graft works you have to use the pathmapper and add a additonal 0 @ the curves in the mid position or use flatten component and use the additional parameter and set the first to path 0, the second to 1 ...etc

Permalink Reply by Claas Eicke Kuhnen on February 21, 2010 at 11:52am

Ok, how and where can I see the path structure problem?
I do not know why the path get messed up after offset.

So the param viewer tell me stuff about the curves
Path = 1
{0;0;0}
(N=1)

I added a flatten to all curves and it worked.
Path = 1
{0}
(N=1)

I assume that because sometimes I had {0;0;0} or {0;0}
that this caused the issue. What does that man?
Looks to me the curve was flat (0;0;0 or 0;0) but still there
were y,x,z values.

At least that is what I imagine.

So am I correct when the order was not an issue for the loft
but the curve 3D data messed up?

Also what does reparamaterize mean?

Permalink Reply by to] on February 21, 2010 at 12:04pm

Class

please read inside that discussion (http://www.grasshopper3d.com/forum/topics/path-mapper?commentId=298...)
or the primer about data structure there it is explained what a data tree is and how it works and it has nothing to do x,y,z information .....
there also the topic about reparameterize is declared... this are all very important topics without that knowledge you could not get very far with grashooper
...

Permalink Reply by Claas Eicke Kuhnen on February 21, 2010 at 12:37pm

Ok

this makes sense now.

This all describes an order not space coordinates.

I read through the primer often but it does not answer
a lot when you start learning GH.

But again thank you for the help.

Permalink Reply by to] on February 21, 2010 at 1:01pm

about reparameterize:
so if you have a surface or curve it is defined parametrical with domains
so what is a domain
a curve is when it is created in rhino set to 0 - curve.length so it is quite hard to work with that information so in case of you want the middle point of a line you have to set the t parameter to curve.length/2 to get that point
so to work efficient with that parameter you reparameterize it to set it from 0(start point) to 1(endpoint)
the same fact is if you work with surface but you have to be aware because a cure has only one and surface have two (u and v domain)
hope this rough explanation helps a little
if you want to know more just ask

and no problem i know in the beginning it's quite hard to get away from the modeling thinking to the parametrical way of building up a project because you have to know a lot more about the program and the topology of geometry

Permalink Reply by Claas Eicke Kuhnen on February 21, 2010 at 1:27pm

Very true

I wish the manual would be a bit more written for beginners
or the site would have some step by step tutorials.

Grasshopper is an amazing concept - we look into it for product
design and found it not comparable to a true design history like
SolidThinking or SolidWorks because fillets for surfaces
are not supported but for fast conceptual form developments
it is amazing.

Fillets can still be added later in Rhino itself.

Some student are totally in love with it.

Permalink Reply by Luis Fraguada on February 21, 2010 at 1:41pm

I agree that for beginners, the Primer is a little light on Data Trees...they are quote important. But, they are also not complete...at least I do not think, thats for David to tell us. When the primer v2 was written, trees were quite new, and there were few tools to implement them. I think the concept is clear, but there are occasions where several options arise as to how to treat the data. Maybe Andy will release (or is working on) a v3 Primer with something more in depth for beginners on trees...

Permalink Reply by Claas Eicke Kuhnen on February 21, 2010 at 1:58pm

It happened quite often during class that we worked on a model or I gave a demo and bang something did not work right, which worked in a different situation. Quite frustrating.

But as I said when it works the students love it.

Surfacing with GH is just a dream in Rhino.