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LDCad: rubber band in 3D - Printable Version

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LDCad: rubber band in 3D - Milan Vančura - 2016-04-08

I tried to put the rubber band on a construction which is not flat. Something like
    .

The default what LDCad does is
    .
There are two problems: the green and red ball rods do not point to the previous and next circle correctly and rubber band is twisted between the top left an top circle. Is there a way how I can fix it manually? I did not find any way to change rods directions (only their length). And any change of their "roll" did not help with the twisted band problem.

Or should I use "bezier" instead of circles? Thanks.

RE: LDCad: rubber band in 3D - Roland Melkert - 2016-04-08

This is a very interesting shape, it also seems to bring the generator to it knees Smile

The main problem is the circle point object try to project the band on a 2D plane, which will go weirder and weirder when using these kinds of twists.

The twisting can be fixed by using different 2D planes (The 'direction' value in the point's property dialog). But you will keep the crooked previous next spheres.

The bezier points are truly 3D so they will work no matter what just keep an eye on the local point's axis' (they all need to be <=180 deg rotated compared to the previous point).

A little test run gave me this:

   

It probably needs some more positional etc tweaks to get completely right.

RE: LDCad: rubber band in 3D - Milan Vančura - 2016-04-11

Thanks for tips, Roland. I was able to put the rubber to a shape close enough so children could understand those pictures at my weekend workshop Smile Later, I want to learn more with this because it is not intuitive so "just click" method does not work - even for me who worked with computer graphics for years and used Bezier shapes a lot...

RE: LDCad: rubber band in 3D - Roland Melkert - 2016-04-11

(2016-04-11, 11:19)Milan Vančura Wrote: Thanks for tips, Roland. I was able to put the rubber to a shape close enough so children could understand those pictures at my weekend workshop Smile Later, I want to learn more with this because it is not intuitive so "just click" method does not work - even for me who worked with computer graphics for years and used Bezier shapes a lot...

If you have any ideas on how to improve creating these kinds of shapes I'm always open to suggestions.

On the bright side, these kinds of bands are great for training spatial awareness Smile