helix to egg?

I'm trying to resolve a projection of an helix to an egg shaped surface.

helix could be inside or outside it doesnt matter. but it's axe should be aligned with egg´s vertical axe

my goal would be getting a "helix like curve" with variable radio and this variation should follow the shape of an egg..

I have no idea if it is possible in a simple way.

first choice was Project a helix curve to a brep..... of course it didn't work, as i need a radial projection not a vectorial one.

Any Ideas?

I will really appreciate any help or opinion on this.

Regards and many thanks in advance for any kind of help

Replies to This Discussion

Permalink Reply by Michael Pryor on February 7, 2013 at 1:31pm

map to surface

Permalink Reply by Alejandro REBOREDO on February 7, 2013 at 2:14pm

Many many thanks Michael ....maybe this could work !

I have the helix, and the egg (golden ratio egg shape)

I have "map_srf" GH element and it asks for a curve a source (?) and a destination surface (the egg) I used a cylinder same diameter of max of egg (1,4m) and same height.(about 1,9mts)

we are allmost there. ...

but spiral isnt exactly at the edge surface, is some centimeters inside (12 cm.) I'll keep trying and I'll take another look on the helix generation to see if it's a curve interpolation problem.

many thanks again.

Permalink Reply by Michael Pryor on February 7, 2013 at 2:52pm

If you put your files we can help further

Permalink Reply by Alejandro REBOREDO on February 7, 2013 at 3:10pm

I'm cleaning up files to be human readable and I'll be back.

Permalink Reply by Alejandro REBOREDO on February 7, 2013 at 6:43pm

Michael: Here is my approach (humble newbie aproach by the way)

I' allmost there... but not there yet.

your suggestion point me to the right direction but I'm missing something maybe the generation of helix is not good as I get it somewere and made a few adjustments...

I also used "brep closest point" before helix drawing, and the ressult is an incomplete projection of the helix on the egg but accurate

"map to surf" shows me an extrange aproximation but not the curve applied to the surface.

Thanks again in advance for your help.

sorry for my poor english and my poor grasshopper knowledge too ;-)

Attachments:

hegglix.gh, 14 KB

Permalink Reply by Yoann Mescam (Systemiq) on February 8, 2013 at 5:17am

Did you see this (from TheChosenOne) already ?

Permalink Reply by Alejandro REBOREDO on February 8, 2013 at 1:42pm

Thanks a lot it seems to be exactly what I need

I'll take a look on your links

Thanks again

Permalink Reply by Hannes Löschke on February 7, 2013 at 1:48pm

Fosters Gherkin comes to mind. If it's someting like this, you want to achieve, make sure your egg is a roational surface and genereate a diagonal UV-grid.

Permalink Reply by Alejandro REBOREDO on February 7, 2013 at 2:09pm

nice info, thanks. but i need a spiral with several turns around the egg.

ill give a try any way to see if I ca use some points to generate the curve.

thanks

Permalink Reply by Benjamin Felbrich on February 8, 2013 at 12:03pm

or this:
-build the egg's axe as a line
-divide the curve according to the destinated accuracy
-move each of these points by a certain length and vector
-interpolate

you could generate the list of vectors according to the t-values of your points(graph mapper for "smooth" values)

maybe you get more control in terms of the shape and starting-/end-direction?
and you could also apply a curved axis

Permalink Reply by Alejandro REBOREDO on February 8, 2013 at 1:44pm

Thanks everyone for a lot of helP !!!

I'll check every link and suggestion to see which one is more suitable but it seems that all of them are very usefull

Thanks again

Alejandro

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