How to get a good tilt on a solenoid curve ?

Hi !

I’m trying several methods to make a rope winding around a winch drum.

You will find here a page with a link to a short movie of my current trial.

http://securimax.chez.tiscali.fr/starblend/winchtest.html

I’d want to use a curve path with a solenoid shape. I can get a nice curve, but the tilt is always changing along this path, and after many hours of tweaking, I can’t do anything good !

Is there a method to keep the axis of the tilt plane all along the curve ?

My current method (used in the movie) is simple, but uses a discontinuous rope made of 450 small rings that are child of an empty animated by some Ipos. I have also tried to make a solenoid pipe with a lattice. it is interesting, but lattices have only 64 cells on one axis, and can’t be added or parented each other, so I can’t use them…

My method method doesn’t allow flexible rope, so I cant’ use a pulley in my animation ! Using a solenoid curve, I could use dupliframe, and quite every other tool I need !

Any help would be appreciated !

Thanks in advance!

Philippe.

Yep, tilt is very obnoxious :frowning:

Could be, but you will get 180° jumps anyway when beveling, I’m Afraid

I happen to have written a Pulley Script! Could be of any help?

https://blenderartists.org/forum/viewtopic.php?t=39693

For the Winch I have no immediate solution though :frowning:

Thanks in advance!

Philippe.[/quote]

Hi S68 !

Thanks for your response.

You said :

Could be, but you will get 180° jumps anyway when beveling, I’m Afraid

Yes, it is my main problem !

Your Sailboat avi example is very nice !

I have downloaded your script, and I’ll try it as soon as possible.

Checked your demo blend file… but without understanding a lot ! %

I’m afraid that I’ll have to search more about my curve problem.

To be followed…

Hi !

I’m currently solving my problem with the winch… I’ll make a new movie as soon as possible, and maybe a tutorial, if I can explain how I did !

I have solved my tilt problem, and avoided the 180° twist !

I have used The Parent Curve Deform feature, and a Bezier Curve instead of a NURBS Curve.

The Track and pointing Up axis of the curve are choosen exactly the opposite of the settings of the object.

I can bend my curve as will, and the rope follows it perfectly without any twist ! The last vertices of the rope are used as parent to an empty that allows to hang an object used as a load under the rope.

I have still some work on it , but I have the hope to reach my goal.

To be followed.

Philippe.

Take this in good spirit(this is to help not to hurt):

“To be followed.”

I think you mean “To be continued”, same meaning but followed is never really used in that phrase.

“I have still some work on it , but I have the hope to reach my goal.”

The verbs should be swapped around to be:

“I still have some work on it, but I hope to reach my goal”

Pedant mode ON

While the sentence construction may sound quaint or poetic it is still syntactically correct. It makes perfect sense: there are no anomalies.

Hi MacGyver !

Thanks a lot for helping a poor frenchie improving his english!

I’ve just got a phone call from england and it wasn’t so usual for me.

It wasn’t easy at all ! %|

Philippe.

Your English is good enough for me. I think its even a bit poetic :smiley: .
I hope you find the time to post your tutorial. Flipping paths have always driven me nuts, that’s why I avoid them whenever I can. It happens with bevel objects, path deform and objects following paths. Everything is so smooth, then it abruptly twists. I really believe the coders should find a way to avoid this behavior. One shouldn’t have to resort to workarounds to use these things…

Thanks Graphics.

Well, I hope too that coders will find a real solution for this flipping problem.

For my own, I do not pretend to have solved it completely, because I have only set my animation with axis put in directions that avoid the problem.

I’m quite sure that if I bend my curve in some particular angles, the problem will appear again !

We have to tweak a lot the Track and Point-up axis settings to get the required effect. Sometimes the easiest way seems to make a cut in the sequence and merge with second curve path where the twist appears !

This method is efficient, but is not elegant technically, and needs more time.

I have to work more before posting a new movie and a blend file…

To be continued… :wink: All good MacGyver ?

Philippe.

Philippe -

I am currently having a similar issue with using a Bezier circle bevel object on a Bezier curve. I was reading this thread and I’m trying to figure out this technique you describe. I tried a Bezier curve as the Deform Parent to a Bezier circle (and I also tried a mesh circle). I tried “curve follow” and “curve path” but they don’t seem to have an effect. “Curve stretch” did something, but not what I want.

Any chance you could please explain it in a little more detail? Is the rope a mesh? How exactly did you get it to follow the curve?

Hi Yasoo2 !

Yes, the rope is a mesh.

No mystery in the method, but I have spent almost two days making a tutorial. I hope that I will be able to put it here in the next days or sooner…

I have got a problem with the soft that I use to make PDF files (PDF studio from Micro Application. It is a not too expensive but bad soft that destroys
my page settings, and gives a crapy result. So I’m kooking for an other PDF soft. A free one, I hope !

To be continued.

Philippe.

Hi !

My winch tutorial is done. I’m not sure that it will be very usefull. It is almost one of my firsts tutorial, so let me know.

You will find here on a special page the tutorial and a blend file.

http://securimax.chez.tiscali.fr/starblend/winchtutorial.html

I hope you will like it… %|

Philippe.

Weeee, smart :slight_smile:

Stefano

Thanks S68 :stuck_out_tongue: !

Hi !

I Come back with a new movie :

http://securimax.chez.tiscali.fr/starblend/winchtest.html

The link has been updated. Curve deform is a great function !

I have not enough time to improve the tutorial, but I must say that the method described in the tutorial can be simplified. Less empties are used now, and the cradle of the winch is now the parent of all the other objects, so it is easier to move all the different parts.

Philippe.

Great animation, Philippe :smiley: ! But I got only black frames for the first half of the movie. What is visible is amazing, though. Glad you finally figured out paths and curves. Hope you find the time to enlighten us with more tutorials.

Very nice animation.
I like the little swinging motion you have going on at the end. Just waiting to see how they get the box through the hole in the wall.
The bricks looked a little strange on the left side, where the mortar is - maybe indented a little too much or too regular a pattern.

Quite an elaborate setup you have there.
I just quickly skimmed through it, but I plan to look into it more thoroughly soon. Though, I may wait if you are planning to update it soon :slight_smile: Were you ever able to get around the problem of twists in the curve, I mean instead of just hiding them? …

The animation played fine here, though I did have to download it a second time as for some reason with IE 6, only a short part of the animation was downloaded at first; the second time it got the whole thing.

Hi !

Thanks everybody for your comments !

I don’t think that I’ll have time soon for an improved tutorial… :-?

In this animation, the curve has no twist at all. The twists appears if you make turns with the curve using the 3 axis, and only if you go backward to 180°.

I’m not sure this is clearly understandable, because of my bad english…

The problem is shown on one of the last pictures in my tutorial.

For the question : How they will get the box through the hole ?
I think that they could push a long wood plank under the case and pull the case, using the plank as a slide. :wink: I’d do like that for my own !

I’d want to show this, but I’m not good enough yet to do realistic characters… Maybe later ! %|

Philippe.

I wonder if the twisting behavior of paths is being tackled by the developers? It’s really bothersome. I wonder if it also happens on other better known apps? Probably not.
It would be nice if paths and curves has this Ctrl N and the normals and twists are recalculated and placed in an orderly manner. Maybe someone could do this with a script? What is happening when the path suddenly twist? is it confusing 180 degrees with 0? (Or is it 360 with 0). I’m not very good with math, but this twisting behavior means that paths are not very good with it, either…

Hi Graphix !

Unfortunately, my main lacks are math, programming and music…

I hope too that someone will fix this twist problem one day…

Philippe.