Hi i’m italian, so excuse me for wrong, i try to design a coaster in blender with bezier,
http://digilander.iol.it/bmcoasters/cobra.blend
here is my .blend file with my problem, can u solve it?
Thanks in advance
I’ve got no idea how you did that (except that the track is a nurb curve) so I can’t help you out. But this looks like a very cool project! Can’t wait to see it finished.
Thank nemesis for support, but i think that i never finish this, because a i have this problem from a looooooong long time 
if i solve it, i can finish in few days 
if i solve it…
BTW, is your problem the twisted part in the middle if the tragectory(not sure about spelling)?
Hi!
You can post to me via e-mail in Italian (look on your left) but keep on english on boards :).
I got the problem, your curve switches of normal direction. I assume you have made half of the track, then duplicaded and mirrored that half.
Then you joined the two curves together.
This is why you got flipped normals.
Problem is unsolvable, as far as I know.
YOu should make the track as a single bezier from the beginning…
Good luck
Stefano
s68 I no mirrored the curve, is only 1 bezier
Hi Xenobius!! I see your still having trouble. Is this the same piece of track you showed me earlier?
Try the same method I told you about then:
Enter edit mode select all and rotate -25 deg. It seems that this time -50 seems to work instead of -25 as we did before.
You can then use tkey to adjust the end of the curve where it doesn’t quite want to come back right.
Thank u Brian, but doesn’t work well.
Someone have another wrinkle?
Thank U all, its nice to see that someone have an interest to my design problem, its first time
Hey there!
I had a chance to look at the blend file you emailed me yesterday. I was not able to get the silly wrinkle (warp, kink, etc…) out of the center of the curve. Somehow the rotation of the vertices is all messed up. Very interesting problem, I tried rotating the curve handles this way and that (with both the T-key and the R-key). Nothing I did would fix the curve. So, I did the next best thing and created a new one for you to look at. Here is a link to the blend file:
http://www.seesystems.com/curt/cobra2.blend
I hope this helps you get the coaster rolling!
Ciao for now!
Curtis S
WOW!
that looks mighty cool, i think i may try and make one…
I still need help… its possible to apply the “switch direction” command to only a portion of the curve?
Help help help! i wanna do this model, please help!