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Topic: (Fixed) Spline Tangents  (Read 8042 times)

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September 24, 2013, 05:40:27 pm
Hi IStonia,

Yes, Spline Tangents again. lol

As there is no way I can find to edit the direction of the spline tangents used for "Instance Spline" I was hoping the results would be consistent.

Quick example:-

Cylinder and 3d natural spline
(although I still do not understand the calculations being used for "Naturalize spline" given the output I see at times. But will leave that for now)



Use "Instance spline" with "Align to Spline Tangent" and "Use Spline Points", which gives result of:-



Now change to "Use Input" and the "Spline Tangents" being used appear to change direction:-




I will presume that is a bug?

When you have time, could you please look at that?

Thanks,

-Steve

File Attached:-


« Last Edit: November 05, 2013, 07:12:33 am by steve »

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September 26, 2013, 10:11:28 am
Hi IStonia,

I was looking more at this.
It appears even if I use "Spline vertex"-> "Tweak" with option "No auto naturalization" enabled, when tweaking the vertex, the spline tangents of the splines do in fact change (certainly the ones used for the "Instance Spline").

When functions are relying on such as "spline tangents", then there really needs to be a way for the user to see and control them. As it is currently, the results can be too unpredictable.




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September 27, 2013, 11:02:58 am
I thought I would post the problems I see with the "Naturalize spline".

Example:-

I am placing a spline around an extracted surface, unless the vertex points are equal distance I get quite bad kinks/bulges in the spline path:-
(Here I was going to edit the tangent handles on the currently naturalized vertex spline, but decided to take screen grab and post info instead)



If I do similar in other applications that have a auto handle function (automatically calculates tangent handle lengths) , I do not see that problem. Here is an example (on that same extracted surface) from Blender:-



Another example, is where if 2 spline vertex are close together, with the vertex at greater distance on either side of those 2 vertex, there is a loop in the spline, where the spline loops back over itself:-



Again, in other applications such as Blender, I do not see that problem. The Tangent handles are created that give a smooth transition along the spline:-



My apologizes for having a bit of a rant about this, but I have been fighting with the splines in Nvil for quite a long time, and I am running out of hair to pull out. LOL.

When you have time, could you please have a look at this. No rush, I know you are busy.

Regards,

-Steve









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October 30, 2013, 10:45:56 am
The bug is fixed.

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November 05, 2013, 07:12:04 am