[x3d-public] TwoSidedTexture node

[Andreas Plesch]

Hi Don,

there should be quite a few applications where it is possible to
reduce a volumetric object (a thinner wall, a sheet of paper) to a
surface.

BackAppearance seems easier to design from a spec. perspective but
much harder to implement. One question is if just providing a non-null
BackAppearance node would be enough to signal special treatment of the
back (side of inverse normals) or if there needs to be an additional
field for shape, similar to 'solid'.

Another initial, minor question is how is TwoSidedMaterial expected to
interact with solid='true' surfaces ? Presumably by not using the
backMaterial but since solid='true' is the default another option is
that TwoSidedMaterial always implies solid='false'. After all, this is
surely what the author intended as she could have used a regular
Material otherwise. I could not find that resolved in the spec.

-Andreas



On Sat, Nov 4, 2017 at 12:23 AM, Don Brutzman <brutzman at nps.edu> wrote:
> Very interesting ideas, thanks guys!
>
> It looks like you have made a good case for defining such support in X3D v4,
> especially providing benefits for things like room and building modeling.
>
> Hope that you continue to consider how best to evolve the existing X3D Shape
> Component in this direction.
>
>
> http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/shape.html
>
> In particular please compare/contrast design alternatives with
>
>         12.2.3 Two-sided materials
>
> http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/shape.html#TwoSidedMaterials
>
> Looking forward to further discussion and an eventual proposed specification
> improvement, "12.2.4 Two-sided texture mapping" perhaps.
>
> all the best, Don
> --
> Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
> Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
> X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman



-- 
Andreas Plesch
Waltham, MA 02453