Le 24/07/2016 08:17, clipka a écrit :
> Am 24.07.2016 um 07:55 schrieb Le_Forgeron:
>> Le 24/07/2016 04:13, clipka a écrit :
>>> What's been bothering me about POV-Ray's Bezier patches is that we don't
>>> have some kind of bezier mesh to support non-union CSG. Do you think you
>>> can throw together a nurbs mesh primitive?
>>
>> what do you want ? or what is the need ?
>>
>> It's a 2D finite surface, involving it in CSG does not seem to make sense (to me).
>> (it is rarely closed, until you glue many nurbs together)
> 
> ... and that's exactly what I'd love to see. Just like you glue many
> triangles together in a mesh.
> 

So, do you want a "container" for multiple nurbs with additional "inside" property so
it can be used in further CSG operation ?
(assuming such container would assert that the collection of nurbs defines one or more
closed surfaces with non-zero enclosed volume(s))

Using the same approach as for mesh (inside_vector), it might be possible.
I just anticipate a high cpu cost.

On the same line, while we are at it, such container could also handle bicubic_patch
the same way.

Any suggestion of name for that container ?

Still any interest for nurbs.get_vertex() ? or can I forget it ?

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clipka <ano### [at] anonymousorg> wrote:

> @LanuHum:
> Does Blender provide full support for NURBS? If so, then this looks like
> an urgent job for you!

It is very good that made Le Forgeron!
Le Forgeron, thank you!
Hair in Blender - NURBS.
There are also some tools for editing NURBS curves.
If it can be used in CSG - it is very good

:D

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Le 24/07/2016 11:31, LanuHum a écrit :
> Hair in Blender - NURBS.

Duck & Cover.

As illustrated in the first post, a simple scene with only 4 nurbs of degree 6 & 3, a
box and a cylinder took already 1 minute on 6+6 cores... and there is nothing fancy in
the scene. And I do not believe the box or the cylinder to cost.

The bounding box might helps a bit, but I predict a sky-rocketed render time if you
model any individual hair with nurb, short of modeling only Britney after the barber
shop.

Of course, not a problem if using nurbs for the head of hair, with some mapped
pigments or textures.

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"LanuHum" <Lan### [at] yandexru> wrote:
> clipka <ano### [at] anonymousorg> wrote:
>
> > @LanuHum:
> > Does Blender provide full support for NURBS? If so, then this looks like
> > an urgent job for you!
>
> It is very good that made Le Forgeron!
> Le Forgeron, thank you!
> Hair in Blender - NURBS.
> There are also some tools for editing NURBS curves.
> If it can be used in CSG - it is very good
>
> :D

Example:

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Attachments:
Download 'nurbs.jpg' (65 KB)

Preview of image 'nurbs.jpg'

Sorry! This is surface.
Nurbs surface also supported

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Attachments:
Download 'nurbs_surface.jpg' (192 KB)

Preview of image 'nurbs_surface.jpg'

Am 24.07.2016 um 11:31 schrieb LanuHum:
> clipka <ano### [at] anonymousorg> wrote:
> 
>> @LanuHum:
>> Does Blender provide full support for NURBS? If so, then this looks like
>> an urgent job for you!
> 
> It is very good that made Le Forgeron!
> Le Forgeron, thank you!
> Hair in Blender - NURBS.

Are you sure Blender hair uses NURBS /patches/ (which is what LeForgeron
has implemented) and not NURBS /curves/?

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Am 24.07.2016 um 09:08 schrieb Le_Forgeron:

> So, do you want a "container" for multiple nurbs with additional "inside" property
so it can be used in further CSG operation ?
> (assuming such container would assert that the collection of nurbs defines one or
more closed surfaces with non-zero enclosed volume(s))

You got it :)

> Using the same approach as for mesh (inside_vector), it might be possible.
> I just anticipate a high cpu cost.

Can't be worse than using a simple union of individual patches.

> On the same line, while we are at it, such container could also handle bicubic_patch
the same way.
> 
> Any suggestion of name for that container ?

"nurbs_mesh"?


> Still any interest for nurbs.get_vertex() ? or can I forget it ?

Sounds like a useful idea.

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clipka <ano### [at] anonymousorg> wrote:
> Am 24.07.2016 um 11:31 schrieb LanuHum:
> > clipka <ano### [at] anonymousorg> wrote:
> >
> >> @LanuHum:
> >> Does Blender provide full support for NURBS? If so, then this looks like
> >> an urgent job for you!
> >
> > It is very good that made Le Forgeron!
> > Le Forgeron, thank you!
> > Hair in Blender - NURBS.
>
> Are you sure Blender hair uses NURBS /patches/ (which is what LeForgeron
> has implemented) and not NURBS /curves/?

I realized this later, and wrote about it.
Blender has four primitive NURBS.
They can edit: transform vertices and extrude.
You can also create NURBS surfaces from NURBS curves using loft.
Create patches 4 x 4 - uncomfortable modeling.

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Attachments:
Download 'nurbs_surface1.jpg' (142 KB)

Preview of image 'nurbs_surface1.jpg'

clipka <ano### [at] anonymousorg> wrote:

> > Any suggestion of name for that container ?
>
> "nurbs_mesh"?


If it's a closed 3d shape composed of NURBS mesh(es), then maybe "envelope" to
differentiate and disambiguate from a (simple) open mesh?

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Am 24.07.2016 um 18:10 schrieb Bald Eagle:
> clipka <ano### [at] anonymousorg> wrote:
> 
>>> Any suggestion of name for that container ?
>>
>> "nurbs_mesh"?
> 
> If it's a closed 3d shape composed of NURBS mesh(es), then maybe "envelope" to
> differentiate and disambiguate from a (simple) open mesh?

Sounds far too vague and unrelated. Besides, I think it would be smart
to also support non-closed NURBS patch meshes, just like mesh also
supports non-closed triangle meshes.

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