[x3d-public] Fitness of X3D for 3D Printing?

[patola at makerlinux.com.br]

First, thank you all for your responses. I became even more
enthusiastic about X3D after I took knowledge of the cura import plugin,
this is just a few days after I myself submitted a small contribution to
cure. I subscribed to the PR immediately. I saw that it was already
accepted and merged, and I will be testing it as soon as I get the
compiled version. 

I knew that Cura is internally based in triangles, I
understand that this applies to all 3D Printing slicers on the market
currently, and I do not think the NURBS support is something highly
demanded now, but I am quite convinced that it will be in the near
future. There is also some discussion about support of ARCs - and most
firmware like marlin and repetier already support the gcode arc commands
(G2 and G3). The slicers that support it seem to be using the arc
commands from "inferring" the arcs from the triangles -- Simplify3D was
doing that before version 3.0 but dropped this feature because it caused
problems. However I think a comeback is likely, because the artifacts
caused by interpolation and/or approximation doing in the modeller or
the slicer are becoming more evident as the techniques for 3d printing
improve. 

I also understand that Blender has a relatively weak NURBS
support, as in having very few tools to deal with it - I took a few days
to learn how to close a single NURBS cylinder - but I also think that it
is because it is not very used, not very needed, and that will change as
elsewhere in the 3D printing stack "real curves" are needed. I might
even try experimenting with the current x3d import/export plugin to add
the nurbs components. As far as I saw, it is a straightforward 1-to-1
mapping. 

BTW, there is something else I could still not find on the
X3D standard. 3MF has a slice extension that in practice allows to embed
the gcode, or x3g [makerbot format], or slicing code equivalent in the
file. Is it possible to extend X3D to support slicing information too?
Furthermore, what would be the most convenient metadata to designate
special types of material, like support material (that might need to be
dissolvable, or coarser, or discarded altogether depending on the 3d
printing technology)? 

Thanks again! 

Cláudio Sampaio - MakerLinux


Em 18.09.2016 12:22, Alekseyev, Vsevolod (NIH/NIAID) [E] escreveu: 

>
X3D support is coming to Cura in the next release:
https://github.com/Ultimaker/Cura/pull/914https://github.com/Ultimaker/Cura/pull/914
[1] . There's no support for NURBS geometries, or any kind of curved
geometry for that matter. Cura was built with STL in mind, its internal
mesh format is a triangle set. I didn't feel like hand-tesselating
NURBS. 
> 
> Other slicers that are based on Cura code might follow
suit. I also have X3D import code for CuraEngine (distinct from Cura
proper), which some slicers are using, but haven't submitted it anywhere
yet. 
> 
> X3D import/export modules for Blender don't support NURBS.
Blender, as far as I know, does support NURBS in some way, so there
might be a way to implement import/export with relatively little effort.
I didn't explore the possibility so far. 
> 
> As for the color mixing,
I'll let the more knowledgeable people speak of what is and what is not
in the standard. 
> 
> -------------------------
> 
> FROM:
patola at makerlinux.com.br [patola at makerlinux.com.br]
> SENT: Sunday,
September 18, 2016 10:09 AM
> TO: x3d-public at web3d.org
> SUBJECT:
[x3d-public] Fitness of X3D for 3D Printing?
> 
> Hello all, I am a new
member, I was just subscribed to this list. I am a 3D printing
professional in Brazil (for low-cost, mostly open-source 3D printers). I
searched thoroughly through the list archives but could not really find
my answer. I am looking forward to try and implement import and export
plugins in Blender for a 3d-printing friendly format. I looked into the
standards for both AMF and 3MF, and they do not seem really appropriate.
3MF is nice and full of stuff but does not have any kind of curves,
splines or NURBS. AMF has curved triangles and also allows you to
specify a formula for the curve, but this seems kind of out of hand
compared to "real" NURBS. And since some artifacts - specially in the
amount of material extruded - appear from the interpolation of triangles
to approximate three-dimensional curves, actual NURBS support would be
essential for precise 3D prints. 
> 
> Then I stumbled upon X3D, which
is already implemented in Blender. The latest status of the x3d support
seems that from 2015:
http://www.web3d.org/news-story/improved-blender-import-x3d-scenes 
> 
>
However, it was not very clear to me if X3D, and its blender
import/export addon, would support something fit for material mixing.
FDM 3d printer extruders with the capability to additive mix of colors
are being sold right now, and support for mixing them is already being
implemented in firmware too (with "virtual extruders" for the mixing).
Both 3MF and AMF have proper support for this, AMF having even
coordinate-dependent mixtures support. I have read in the specs that
currently X3D only supports subtractive light, and also no gradient or
mixing for materials, is that right? 
> 
> Does anyone else on this list
deals specifically with 3D printing? I am not aware of X3D support in
any slicer currently. I am curious as to the fitness of this file format
for this task. Am I asking too much? Or maybe it just does not fit its
intended purpose? 
> 
> Best regards, 
> 
> Cláudio (Patola)




Links:
------
[1] https://github.com/Ultimaker/Cura/pull/914
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