[x3d-public] Over next several weeks, I will be ramping up

[Michalis Kamburelis]

Ah, I misread your post in haste -- you wrote "Stereo Lithography (STL)
export converter from X3D JSON to STL". So X3D -> STL, not the other way
around. My answer was for X3D -> STL, so not that much helpful to you,
sorry! :)

If you want to see how we do NURBS -> simpler things, it's in

-
https://github.com/castle-engine/castle-engine/blob/master/src/transform/castlenurbs.pas
(calculate points and normals on NURBS curve / surface)

-
https://github.com/castle-engine/castle-engine/blob/master/src/scene/x3d/x3dnodes_standard_nurbs.inc
(using above, e.g. NurbsPatchSurfaceProxy uses TNurbsSurfaceCalculator to
generate X3D TIndexedQuadSetNode)

Regards,
Michalis




wt., 20 gru 2022 o 17:20 John Carlson <yottzumm at gmail.com> napisał(a):

> Sorry for any confusion, I’m trying to convert abstract geometry (in X3D)
> to triangle or face meshes in ECMAScript and then to STL.  If someone has
> done this before, how did you choose a mesh for each shape (sphere, cone,
> cylinder, extrusion, 2D). I already know NURBS is complex, for that, but
> I’ve not done animated NURBS, which sounds really hard, and perhaps not
> good looking???  Has anyone animated NURBS?   Jello, anyone?
>
> I’m not looking to produce X3D at this point,  going from a low level
> triangle code to abstract geometry sounds really hard, but perhaps
> lucrative?   Isn’t this what the scanning group is doing?  Do they use
> OpenCascade, C++, and Python?
>
> I’ll look at your Pascal code now.
>
> John
>
> On Tue, Dec 20, 2022 at 6:58 AM Michalis Kamburelis <
> michalis.kambi at gmail.com> wrote:
>
>> STL already contains a simple list of triangles. So if by "tesselation"
>> you mean "ability to produce triangles from more complex shapes", you don't
>> really need it for STL :)
>>
>> Note that CGE, view3dscene and https://castle-engine.io/convert.php can
>> convert STL -> X3D. The code to handle STL is really simple and you can
>> likely adjust it for other purposes / libraries / languages :
>> https://github.com/castle-engine/castle-engine/blob/master/src/scene/load/x3dloadinternalstl.pas
>> .
>>
>> Regards,
>> Michalis
>>
>> wt., 20 gru 2022 o 12:07 John Carlson <yottzumm at gmail.com> napisał(a):
>>
>>> [image: image.png]
>>>
>>> The Stereo Lithography (STL) export converter from X3D JSON to STL looks
>>> like low hanging fruit. I just need to find some good tesselation code in
>>> ECMAScript. I already have a basic framework. Can anyone recommend A-Frame,
>>> Three.js, Babylon.js, Unity, X3DOM or X_ITE code for doing tesselation, or
>>> is it built into WebGL?  Meanwhile, I will be working on meshes and
>>> creating a project, etc.
>>>
>>> On Tue, Dec 20, 2022 at 4:45 AM John Carlson <yottzumm at gmail.com> wrote:
>>>
>>>> Over the next several weeks, I will be ramping up for potential return
>>>> to work, testing out CTS coping skills (laying on a different side, taking
>>>> breaks), computer hygiene, sleeping hygiene etc.
>>>>
>>>> My wife has given me the thumbs up to return to work remotely.
>>>>
>>>> So if there's any X3D tasks, I should be able to pick some of them up,
>>>> I will look at the wishlist.
>>>>
>>>> BTW, has anyone attached Gmail to GPT-3?
>>>>
>>>> Everyone have a merry xmas and happy new year.
>>>>
>>>> Thanks!
>>>>
>>>> John
>>>>
>>> _______________________________________________
>>> x3d-public mailing list
>>> x3d-public at web3d.org
>>> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>>
>>
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