Authors:

- elephant_smooth_triangle_set.x3dv is based on
    https://openlibraries.svn.sourceforge.net/svnroot/openlibraries/trunk/media/models/glittering.x3d
  It was simplified by hand (to leave only simple IndexedTriangleSet
  with coordIndex and Coordinates) and convertex to classic encoding
  by view3dscene. OpenLibraries is under LGPL
  (http://openlibraries.org/wiki/OpenLibraries,
  https://openlibraries.svn.sourceforge.net/svnroot/openlibraries/trunk/COPYING)
  so this example should also fall under LGPL.

- test_texture.png based on this photo:
  http://gimp-savvy.com/cgi-bin/img.cgi?ufwsMV1VJR1LXOE702
  from Copyright-Free Photo Archive:
  http://gimp-savvy.com/PHOTO-ARCHIVE/
  Public domain.

- Everything else by Michalis Kamburelis aka Kambi, VRML / X3D written by hand,
  texture created in GIMP. Some of this is a subset of
  [http://vrmlengine.sourceforge.net/kambi_vrml_test_suite.php].
  Free to modify and redistribute under GNU GPL >= 2.

So everything should be compatible with GPL 2.

White_dune problems:
- triangle_fan_strips_smoothing.x3dv: dune doesn't smooth normals on
  [Indexed]TriangleFanSet and [Indexed]TriangleStripSet.
- elephant_smooth_triangle_set.x3dv: like above (larger test,
  and on IndexedTriangleSet).
- cylinder_texture_mapping.wrl (the VRML 97 version) and
  cylinder_texture_mapping_nosolid.x3dv (analogous test but with solid
  field set to FALSE (Cylinder.solid field is available only since X3D)).
  Problems:
  - dune doesn't handle texture alpha channel
  - VRML 97 version has texture stretched on the sides, it seems
    applied two times in S direction.
  - VRML 97 lacks texture on bottom and top caps.
- background_z_oriented.wrl: dune doesn't rotate Background node.
- background_pure_white.wrl: when you look around in dune, strange yellow-black
  colored background appears. While background should clearly be just white,
  proved by placing clear pure_white.png texture.
  Strangely, the yellow color seems to come from
  triangle's material color... (when you change it e.g. to red, the sky
  also gets red...).
- non_convex_face.wrl: dune doesn't handle non-convex faces.
- text_textured.wrl: dune doesn't texture text.

All screenshots were captured with view3dscene, so you can recreate them
and investigate models by view3dscene. They show rendering correct with
respect to X3D spec, assuming view3dscene and xj3d (yes, checked with xj3d
everything here) are correct.

As fas as I know, view3dscene (SVN as of today, 2008-08-03)
results are correct for all of these models.

(Xj3d notes: note that Xj3d also doesn't render it all perfectly,
although it fails in other places and I'm pretty sure these are
unrelated xj3d faults:
- cylinder_texture_mapping_nosolid gets Z-order problems in Xj3d.
  Most probably because they use blending for rendering.
  (view3dscene detects simple yes/no alpha channel and uses alpha_test
  for such textures, as alpha_test avoids Z order problems).
- background_z_oriented has inverted zenith and groud direction
  (seems they have a bug and treat skyAngle wrong, spec says clearly
  it's an angle from the zenith). Anyway, it shows correctly that
  groun-zenith are oriented on Z axis, so Background is correctly
  rotated.
- textured text doesn't seem to be supported by xj3d.
)
