21-03-2007
I’ve been working a bit with curves lately, and stumbled across an easy way to get over curve twist singularity (as you cross the curve’s Z axis)
You get the problem when you’re editing a 3D curve, and it needs to loop /curve in the “up” direction of the curve. As you cross that imaginary vertical line, The curve twists. Just go on as normal, and when you’re done editing, select all the points in the curve and add a hook.
Once you’ve added the hook, pop back out into object mode. Then select and rotate the curve object only (leave the hook alone), and rotate the curve , so you get a more favourable plane. The advantage is that the you don’t need to bother rotating twice (once in object, the other in edit mode).
You can apply the hook modifier and delete the empty to reduce clutter, or leave it and have the option of rotating again later if you move the curve points around and get another twist.
21-03-2007 at 6:23 am
Nice one!!
21-03-2007 at 5:14 pm
Just fixed a typo - I said “edit” when I meant “object”. Obviously one rotates the curve object in object mode, not edit mode.
12-07-2007 at 5:13 pm
Amazing trick!
Thank You Bassam !
The most impressive is that it seems to solve several twists with only one hook…
12-07-2007 at 11:27 pm
Hi.How I add a hook?
13-07-2007 at 1:18 am
Wow! This should make things like roller coasters, looping flight paths and complex ropes, pipes, etc much easier - I assume.
Now, if adding a hook basically fixes the problem automatically, I wonder if a simple re-code could fix it by default so the twrist never occurs in the first place (does anyone ever want the twist?)
13-07-2007 at 3:02 am
Wow, thx for this little tutorial. Finaly I can edit z-twisted curves so quiÑkly and easily :)
13-07-2007 at 6:47 am
This is a cool trick and as with some other tricks i dont have a clue why and how but it works great!
Thanx Twan
ps: I couldnt find the Hook modifier in the modifier menu. Had to use CTRL H. Right?
13-07-2007 at 6:56 am
I like those kind of tricks: simple, yet nifty.
13-07-2007 at 10:15 am
in edit mode you can also try to tilt the curve to solve this issue, grab the handle (in editmode) and press (T) do something with your mouse and see it dissapear…
13-07-2007 at 3:56 pm
Hi folks, thanks for the comments!
You can always add a hook with ctrl-h in edit mode, as you have already found out.
The twist trick isn’t always enough; some mangles are too bad to get out with twist. I found out here teaching a course ( the student was, in fact, making a roller coster) that using the trick in combination with the twist trick is needed for some complex curves.
24-08-2007 at 1:46 pm
wow… you rock!
.andy
29-08-2007 at 9:17 pm
I’m doing a coaster that loops in all directions. The rails consist of a mesh (two cylinders) that follow a curve. By applying tilt to points of the curve, I control the angle of the rails. If I use the trick above, it corrects the Z twist along one axis but introduces it along another. To work around the problem, I’ve broken the track into multiple, separate objects and I manipulate each segment separately. For simpler curves, this trick seems to work great!
Thanks for the tip.
Rick
14-06-2008 at 2:36 pm
Great trick - brings perfect results! You’ve saved my project in some way! Thanks!