[x3d-public] considering general conversion of metadata (to/from Blender)

[Michalis Kamburelis]

2017-04-11 3:42 GMT+02:00 Don Brutzman <brutzman at nps.edu>:
>
> sounds & looks like a pretty general correspondence.  wondering, did you
> notice anything that doesn't seem mappable?

Some bits are not obvious *how and if we should map them*, but nothing
of great interest:

- At the custom properties, you can specify min/max limits (soft and
hard limits), and a tooltip. See the screenshot
https://docs.blender.org/manual/de/dev/data_system/custom_properties.html
. One can invent many ways to export them to Blender (as additional
properties like xxxMin, xxxMax, or as a MetadataSet with
xxxProperty)... but I think it would be over-complicating the idea, at
least at the initial step.

  That is why I did not propose any way to export them to X3D in my
example. It's simpler to treat a "custom property" as just a
name->value mapping, and this probably covers 90% of needs.

- Blender can place "custom properties" at all "data-block types", see
https://docs.blender.org/manual/de/dev/data_system/custom_properties.html
. Not all of them have obvious equivalent in X3D. But that's a general
problem of Blender->X3D exporter, not a problem specific to the export
of metadata. E.g.

  - Blender "Particle systems" have little chance to be ever exported
to X3D (they do have different design than X3D particles),
  - Blender "Armature" and bones are not exported to X3D yet (they
would have to be converted to appropriate H-Anim types, remembering
that "H-Anim" actually means "skeletal animation, not necessarily of
humanoids"),
  - And probably more, see
https://docs.blender.org/manual/de/dev/data_system/custom_properties.html
and https://docs.blender.org/manual/de/dev/data_system/data_blocks.html#data-system-datablock-types
.

But we don't need completeness here. When exporting from Blender->X3D,
users understand that not 100% information from the Blender file can
be sensibly converted to an X3D. Blender does have some different
applications than X3D (e.g. Blender has a myriad of options around
materials and textures suitable for the "Blender Render" and "Blender
Cycles", not really sensible for real-time rendering; it's natural
that these cannot be converted 100%).

I think that exporting metadata at objects, meshes and materials
(things that map from Blender to X3D easily) would be good as an
initial step:)

Regards,
Michalis