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Topic: BSpline.  (Read 10679 times)

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May 17, 2014, 12:26:32 pm
4 mouse clicks,

3 to create spline


[hotkey] +1 to chamfer


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May 17, 2014, 01:18:10 pm
Could you pleas make some tutor how to use this spline? I can not use chamfer dos not work.Also  Whot the figures are on ends of your spline?
« Last Edit: May 17, 2014, 01:19:57 pm by samardac »
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May 17, 2014, 01:43:50 pm
The icons on the end of the spline are showing the start/end (direction of spline). You can change the size of the vertex points in "edit > Preference > General"



"Spline chamfer" is a basic streamline tool.

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May 17, 2014, 02:04:13 pm
Thank you, could you pleas make some tutor or give me link on how to work with spline, becouse have no clear understanding how to work with it, I mean basic operation, how to make spline that I want. There is chamfer, I never know about it, looks like there are and other stuff that I do not know..
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May 18, 2014, 01:47:03 pm
...............how to make spline that I want.

There are various tools for editing splines, and various tools to create polygons from splines (spline slide, spline lathe, spline extrude, spline polygon, spline surface etc), but they will not give you the ability to create the splines as you are looking for.(such as the edge tools/sub_d in Silo)


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May 18, 2014, 02:20:39 pm
Hi IStonia,

With the current splines, it is a bit of a problem for users to create smooth splines, and certainly (IMHO) the Bezier type curves are not the best to work with. With splines(as with some other functions), I do make various workarounds to bypass some limitations and would like to propose a possible implementation based on one of my workarounds (I obviously have no idea if such a workaround would be possible to implement as a function or not).


To try to explain, I will give quick example of one of my workarounds.

There are times I will create a spline, but want it to be smooth without the hassle of keep selecting/changing tangents (and possible getting the problems with the spline looping back on itself).
So here a quick line_list spline:-


I create a spline extrusion (extrusion on both sides of the spline, so the mesh has a center-line running along the original spline).



I then add sub_d to that new extruded mesh


I select the vertex that make up the control positions, and move them if/as needed.



Once in position I want, I select the center-line of the mesh and create a new spline


That gives me the type of result as seen in the edge tools in Silo.

As I put forward, not sure if that would be possible directly on the spline, with a possible function that calls a popup where you add number of divisions(sub_d), allows you to move control points, then apply the result as a new spline (with option to delete input spline)?

What do you think? Possible? Workable?

What do other user think?







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May 19, 2014, 08:45:07 am
Steve, looks interesting, do not know how IStonica can implement it.
Now I use MOI 3D to make some spline works, becouse dealing with Bezier type curves is not for me, very time consuming and hard especially in 3D...
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May 20, 2014, 07:57:24 am
...................becouse dealing with Bezier type curves is not for me, very time consuming and hard especially in 3D...

Bezier curves are not the best, but they are not normally difficult to create.

When creating Bezier curves, the user would normally be able to edit while creating. The auto interpolated smoothing is normally a lot better and does not cause the spline to loop back on itself.

For example.(in other modeling package I have used, and in the 2d graphics that use them)
I would start a bezier curve, the default behavior would be that a single click would create a "Cusp" point, its "in tangent" pointing to last point on spline, and its "Out tangent" pointing to next point. A "click+drag" would create a "Symmetric" point, the drag would give direct edit to that points tangent direction/magnitude (the last/other points tangents would not be affected). While drawing, at any time you could go back to a point and edit its positions/tangency (all handles visible while creating). While still creating, you could go back and move points or change the tangent control type/magnitude. They are normally quick/easy to create.
With Nvil, we only have the click click of creating points, with either a line_list or the poorly implemented interpolation(naturalize) which causes various issues. With the need to then go back and edit after finishing the spline.

So yes, they are a pain in Nvil, but mainly due to how they are implemented.

« Last Edit: May 20, 2014, 08:01:39 am by steve »

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December 27, 2014, 07:05:50 pm
IStonia, please, at least consider adding B-Splines support. Bézier curves are great if you can tweak tangents immediately after placing a knot. This, as far as I know, cannot be done in NVil. Additionally, it's troublesome to tweak tangents in a 3D-space. Dealing with Bézier slows the work down to such degree, that I recently found myself creating shapes (that require curves) in Houdini and importing resulting surfaces to NVil. This is tedious. :(
Things would be so much easier with B-Splines, because you don't have to worry about those blasted tangents.

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December 27, 2014, 10:39:29 pm
Bézier curves are great if you can tweak tangents immediately after placing a knot. This, as far as I know, cannot be done in NVil.
IStonia did add MMB/RMB options to spline creation. MMB creates "In" tangent handle for next spline vertex to be created. RMB creates "Out" tangent handle for last spline vertex created.



 

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December 28, 2014, 12:25:47 am
Nice, I didn't know this trick.
However it doesn't change my attitude towards Bézier curves.

I was making a model yesterday, where I had to use curves to define its shape. It took me over 15 minutes to tweak those blasted Bézier curves' tangents. Somehow they got messed up each time I moved spline's vertices - despite disabled auto naturalisation. I got extremely frustrated and went to Houdini, and I only needed maybe 1-2 minutes to do the same with NURBS curves. It would probably take the same amount of time with Maya's CV curves.

Bézier curves might have been awesome 10 years ago, but in my personal opinion, NURBS curves are far simpler and more intuitive to work with in a 3D environment.
Hell, I'd gladly welcome them in Photoshop too.

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December 28, 2014, 12:47:15 am
Somehow they got messed up each time I moved spline's vertices - despite disabled auto naturalisation.
To move a spline vertex without any auto-naturalisation, you need to disable all 3 options in "Edit > Options > Spline Transform Options"


Quote
Bézier curves might have been awesome 10 years ago, but in my personal opinion, NURBS curves are far simpler and more intuitive to work with in a 3D environment.
I have always thought of "Bezier" curves as being for 2d only, for use in 2d drawing/paint programmes.
All the modeling I do for work is with CAD, so yes, I do prefer NURBS curves.

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December 28, 2014, 12:52:34 am
To move a spline vertex without any auto-naturalisation, you need to disable all 3 options in "Edit > Options > Spline Transform Options"
Thanks Steve, I'll give it a shot.

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December 30, 2014, 01:15:12 am
Gah! Unfortunately whenever I translate spline vertices, I also need to tweak their tangents... :(
NURBS curves would make work so much easier.