For those who trace my spline pachting. This time general_x_spline type with a
lot of characteristics in one spline type available by setting freedom_degree
parameter:
- control points with freedom_degree=1.0 cause B-Spline shape (aproximiation)
- control points with freedom_degree=0.0 cause linear spline
- control points with freedom_degree=-1.0 cause Catmul-Rom Spline
(interpolation)
and all together can be mixed with very user-friendly way.

See thread with the same subject in povray.animations.

ABX

Post a reply to this message

Attachments:
Download 'general_x_spline.png' (40 KB)

Preview of image 'general_x_spline.png'

ABX wrote:
>For those who trace my spline pachting. This time general_x_spline type with a
>lot of characteristics in one spline type available by setting freedom_degree...
>- control points with freedom_degree=-1.0 cause Catmul-Rom Spline
>ABX
>

Catmul-Rom? Like Catmul-Rom subdivision surface?  Povray dosn't support true
subdivision surfaces yet right?  ... Sure would be nice if it did.

Can't wait to see your patch, is it going to be distributed as a source
patch, or will you offer a binary too?

Post a reply to this message

Very good, I really could need Catmull-Rom and Akima Splines and hope they find
its way into Mega- and some day the official PoV release...

-Ive

Post a reply to this message

On Mon, 28 Apr 2003 17:09:01 EDT, "Kitsune_e" <kit### [at] hotmailcom> wrote:
> Catmul-Rom? Like Catmul-Rom subdivision surface?  Povray dosn't support true
> subdivision surfaces yet right?  ... Sure would be nice if it did.

What you mean as "true subdivision" ? Can you point to some url what kind of
subdivision you mean here.

> Can't wait to see your patch, is it going to be distributed as a source
> patch, or will you offer a binary too?

Both, as usually for MegaPOV.

ABX

Post a reply to this message

ABX wrote:
>On Mon, 28 Apr 2003 17:09:01 EDT, "Kitsune_e" <kit### [at] hotmailcom> wrote:
>> Catmul-Rom? Like Catmul-Rom subdivision surface?  Povray dosn't support true
>> subdivision surfaces yet right?  ... Sure would be nice if it did.
>
>What you mean as "true subdivision" ? Can you point to some url what kind of
>subdivision you mean here.
>
>> Can't wait to see your patch, is it going to be distributed as a source
>> patch, or will you offer a binary too?
>
>Both, as usually for MegaPOV.
>
>ABX
>

Sorry, what I ment was that I can use a mesh2 object with normal smoothing
to approximate a SubD surface, but with Catmul-Rom the render engine would
actualy subdivide the mesh on the fly to provide smoothing.

I think this would be useful as I often see artifacts with normal smoothing
in animations, and especialy when a normal statement is included in the
texture.  A basic implimentation dosn't _seem_ that difficult.  I don't
know if your spline functions could be of any use for this, I just though I
recognized the name of the algorithm.

Post a reply to this message

"ABX" <abx### [at] abxartpl> wrote in message
news:7ocqav8fio7ki6vrbhnu7ev60elqg75ub6@4ax.com...

The possibility of being able to tighten a spline with one parameter are
very exciting to me. Most of my modeling is accomplished by building
meshes around splines, so a spline like this would speed up modeling
considerably. Instead of having to trace along a curve with spline
points, I would be able in some cases to use only spline points at major
changes of direction and still have the ability to achieve control over
the curve.

 -Shay

Post a reply to this message