Script for spiral curves - modified

Is there room is your script for a simple parabola programmable

can be used for hanging rope bridge arch arch in building ect…

Tanks

Blender has many strengths, that should be focussed on.
Your line ‘simple parabola’ says it all, a Parabola is a simple object, there is however a script by the elephants dream movie called Hangcurve.py that does a simple Parabola or create curve between two planes, also to make Parabola is not difficult at all using Bezier Curves and the curve handles. This is best done in top view. You can make one side then mirror and it auto joins for precise measure.
Torus Knots and Spirals are much more complex objects that require much math & to make manually can be a real chore.
That said a script that makes arches with definable variables would be handy.

alexv, added your script already to the wiki, keep up the good work.
http://mediawiki.blender.org/index.php/Scripts/Catalog/ObjectPage2#Spirals:p

I tried it with Bezier or poly and it is too approximative

That’s why i was asking to have it done by an equation instead - at least all the points would be at the right place and not more or less where they should be!
Where can we find this script fhangcurve.py for parabola ?
i would like to test it !

is there a URL or a wikipage for this ?

Tanks & Salutations

Thank’s Meta-Androcto. :slight_smile:

RJ2005 yes is is possible to add a simple parabola :yes: I will see.

The Blend with “handing” script is HERE

Hangcurve doesn’t actually make definable Parabola but it could be a start.
http://video.blendertestbuilds.de/download.blender.org/ED/DVD2/production/lib/machine/scripts/
Hope that link is not too long, the script is in the ED archives in the scripts section in hangcurve.blend google will find it.

You do have some points about the bezier method, so long as the cursor is centered it isn’t too bad. I found in one test it worked fine and mirrored correctly, but in another I did run into some trouble. The idea is (for make by model) to make only one side in the top view, then mirror on x axis (did have to duplicate first in the second test) then if needed move on x axis until the points meet at the top. Perfect. mostly :eyebrowlift:
But hey, as I said a script to make Parabola could be interesting, or a setting in the Spirals script.
You can find some more info here:

for the math.
thanks, M.A.

Thanks that does the job, nice script also, thanks for sharing.

Im getting some strange behavior after I create a torus spiral, then I close out the spiral script, if I select the curve then deselect it, I cant select it again in object mode, with the right mouse button, it can only be selected by using either border select or select all, now if I make a duplicate of the spiral (shift d) I can no longer select the original spiral, no matter what I do, the original is completly unselectable. I dont know maybe I have a bug on my system , or maybe its a bug.

With the bezier who tells you that you have a parabola instead of an ellipsoide or hyperboloid curve type ?
you are not certain what you have unless you use a precise equation to get it !

By putting it into the Script with clear identification at least you know that you have a parabola
here is s script to do it but i haven’t tried it yet !

Parabola Script
from Blender import *
from math import *

me = NMesh.GetRaw()
d = 16

for dg in range(0,360,10):
for dz in range(d):
x = dzcos(dgpi/180)
y = dzsin(dgpi/180)
z = 0.1*dz**2
v = NMesh.Vert(x,y,z)
me.verts.append(v)

for h in range(d-1):
for i in range(35):
f = NMesh.Face()
f.v.append(me.verts[i*d+h])
f.v.append(me.verts[i*d+1+h])
f.v.append(me.verts[(i+1)*d+1+h])
f.v.append(me.verts[i*d+d+h])
me.faces.append(f)

NMesh.PutRaw(me, “circle”, 1)
Redraw()

IF someone as work with the hand script can you help

it gives me the error on line 23
—yu have to select two objects ect…
can someone explain what it means and how to make it work !
Tanks & Salutations

For ellipsoid

If all three radii are equal, the solid body is a sphere; if the two equatorial radii are equal, the ellipsoid is a spheroid:

  • ![file:///C:/My%20Documents/A-Temp7/Parabola-Math/Ellipsoid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/251a40d18cbe3c238a555b3ec9dcb3dc.png](file:///C:/My%20Documents/A-Temp7/Parabola-Math/Ellipsoid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/251a40d18cbe3c238a555b3ec9dcb3dc.png) Sphere;
  • <IMG class=tex alt=“a=b>c:,!” src=“file:///C:/My%20Documents/A-Temp7/Parabola-Math/Ellipsoid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/1c101f69cb5c9fca2549cc52aa371d02.png”> Oblate spheroid (disk-shaped);
  • ![file:///C:/My%20Documents/A-Temp7/Parabola-Math/Ellipsoid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/07b70a9113b046e08bf28b121f638b7e.png](file:///C:/My%20Documents/A-Temp7/Parabola-Math/Ellipsoid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/07b70a9113b046e08bf28b121f638b7e.png)c:,!" src=“file:///C:/My%20Documents/A-Temp7/Parabola-Math/Ellipsoid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/ff41a00b219ea3edb0d41dce4d26cc46.png”> Scalene ellipsoid (“three unequal sides”).In mathematics, a paraboloid is a quadric, a type of surface in three dimensions, described by the equation:
    ![file:///C:/My%20Documents/A-Temp7/Parabola-Math/Paraboloid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/b0644e19d3201bf66944d9d762cda982.png](file:///C:/My%20Documents/A-Temp7/Parabola-Math/Paraboloid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/b0644e19d3201bf66944d9d762cda982.png) (elliptical paraboloid, opens upward), or
    ![file:///C:/My%20Documents/A-Temp7/Parabola-Math/Paraboloid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/a83465c3c748f47132a194e856590375.png](file:///C:/My%20Documents/A-Temp7/Parabola-Math/Paraboloid%20-%20Wikipedia,%20the%20free%20encyclopedia_files/a83465c3c748f47132a194e856590375.png) (hyperbolic paraboloid, opens up on x-axis and down on y-axis). You see it not that all cimplicated but only a bit confusing!
    so a parabola equation si the best way to get what a real one!

Salutations

Sorry that did not come out the it should have ?

don’t know how to correct that ?

Salutations

thanks a lot for your contribution alexv! :o

RJ2005> you could edit the post then redo, the code has picked up color and the link source rather than the link. I think go advanced, edit post to fix.
I do agree now that the parabola would be best done with scripting for precise measure.
http://brendonmurphy1.googlepages.com/spirals2.jpg

something anyway. Just some random tests using the script and Curve & Surface tools only.
The barber pole is one duplicated spiral moved slightly to fill the gaps. Too easy.
Thanks, M.A.

http://www.extinctionlevelevent.com/wordpress_ele/wp-content/thumb-cache/4cbee23e310db5ee552206af26ff2bff.jpg

Could the script be modified to duplicate a mesh along a spiral, as in the handle on this sword (click for larger image)?

a curve can be used as a path for a profile!

So you just have to make right profile and i don’t see why not !

Salutations

“Profile” in Blender would mean a 2D cross-section, right?

What I’m looking for is the ability to project, deform, and connect mesh segments. If you look at the close up of the handle, there are parts that can’t be described by a cross section alone, like the chain links.

To Meta Androcoto

Which script did you use to do theses nice spirals ?

The handle looks a lot like a kind of screw!

The handle could use the Screw function by doing a proper profile and then screw it - you should get the effect you need!

Salutations

Ok, the curve that it describes is the catenary, this is not a spiral, I did a new script for Catenary curve, look at http://blenderartists.org/forum/showthread.php?t=88523
Saludos

@alexv > thanks again.
@RJ2005 > alexv’s script all the way. Played around with the settings a lot then in the Curve & Surface tools area different extrudes and press or depress the 3d button (to get flat look). If you play in the Curve tools area, the curves/torus/spirals can be modified further.