Problem lofting!

Hi everyone!

I'm having a little trouble with lofting here. I'm trying to make an arc between each lofted plane (lofted between 4 curves from rhino, 2 above and 2 below). I made an arc between these planes from 4 points.

I managed to loft part of it and it closed up the whole thing. But I tried to loft the rest of it and instead it curve in. When I tried to loft more lines together, nothing showed up. I've tried loft options but didn't manage to fix it.

Attempt below:

This is a sketch i did on rhino of what I'm trying to achieve:

Part of the function here:

I've attached the rhino curves and grasshopper file below.

Would be really grateful if someone could have a look at my definition to see what's going wrong with the lofting. Helpful suggestions on how to approach this will also be appreciated!

I would model each one of these on rhino but the form will be changing!

Extra problem: (if someone can solve this)

Another problem is that the position of the points making the arc need to change as it goes around the curve. Is that something to do with the tangent of the curve? Same as the extrusion, 'cause it's currently extruding in the y direction. Would be great if it could extrude in the direction the "ramp" above!

Thanks in advance to whoever can give ideas/solve this!

Attachments:

rachel_lok_pav_week10.3dm, 56 KB
help.ghx, 1.8 MB

Replies to This Discussion

Permalink Reply by Danny Boyes on May 12, 2010 at 4:36am

Hi Ra,

I think your problem is that the curves you are lofting have different directions. You can use the Flip Crv Component to align curves in the same direction with a guide curve. i.e. First set of loft curves goes directly into the Loft Component the Second set goes into the Flip Component with the First Set as guides this means that if they are already Aligned correctly then the flipping component will ignore them. See Image below.

Also I noticed that the supports were twisted lofts, If this was the desired effect you were looking for you were lucky to have them in the correct orientation to start with. Otherwise you could use this flip method to straighten them out.

Permalink Reply by Ra on May 12, 2010 at 5:25am

Hello again, Danny!

Thanks for the whole flip curve thing. So I guess that means that all curves have a direction? And that was what was influencing the loft?

That's helpful, but the loft is meant to be twisted! I'm just having trouble trying to extrude them in the direction of the curves! 'Cause right now, the top edges are kind protruding. Would that have something to do with obtaining the tangent at all points and some how plugging that back into extrude?

Also, if it's not too much trouble, I got another question: I like what the arcs are doing here:

How would I be able to get it to continue doing this to the rest of these planes throughout the curve, avoiding the arcs from doing this:

Thanks again! I hope others are learning more from my horrible little mistakes!

Permalink Reply by Danny Boyes on May 12, 2010 at 5:35am

I see now, I'll have closer look.

Permalink Reply by Ra on May 12, 2010 at 5:49am

Small note: Just fixed the tangent extrude problem. Got just plugged in the t values from the 'evaluate' from the curves. I also chucked in an amplitude component to control the amount of extrusion!

Permalink Reply by kipodi on May 30, 2015 at 12:21pm