[X3D-Public] X3D player support for NURBS

[Michalis Kamburelis]

Don Brutzman wrote:
> Example scenes and screenshot images for current tests are online.
>
> http://www.web3d.org/x3d/content/examples/Basic/NURBS/
> http://www.web3d.org/x3d/content/examples/Basic/NURBS/images
>
> Tested players include BS Contact (partial), H3DViewer (partial),
> Instant Reality (good), View3dScene (partial) and Xj3D (good).
> Attached is a corresponding visual directory of supporting player
> snapshots. A missing image means that a player didn't render a given scene.

As for view3dscene missing images:

1. Animated Nurbs Patch Surface Head --- view3dscene renders it ok. 
There were problems with incorrect bounding box calculation (fixed now) 
and lack of animation (also fixed now). Fixes are in SVN. Use 
view3dscene from snapshots, 
http://michalis.ii.uni.wroc.pl/castle-engine-snapshots/ , to test them. 
They will be part of next view3dscene 3.14.0.

2. NurbsTrimmedSurface.trimmingControur is not implemented yet, that's 
why the related examples are not correct (but they still render the 
untrimmed surface Ok). Implementing NurbsTrimmedSurface is conceptually 
easy but it's a little tedious and boring... that's why I didn't do it 
yet. Contributions are welcome :), encouraging me to implement them by 
drowning me in more test files, links to other implementations, maybe 
even donations, is welcome too :)

Also, NurbsCurve2D in test files seems to miss the proper containerField 
declaration. This seems to be a bug in test files (but I didn't check 
now what's the default containerField for NurbsCurve2D in "X3D XML 
encoding spec", so it may be our bug as well).

3. The rest of tests from 
http://www.web3d.org/x3d/content/examples/Basic/NURBS/ seems to be 
handled Ok. There are some errors in the test files themselves, 
view3dscene warnings are usually right to point the errors in VRML/X3D 
content :)

BTW, I notice you don't have checks for NURBS interpolators, which are 
quite cool feature. Our demo_models contains simple tests of them, see 
http://castle-engine.sourceforge.net/demo_models.php , tests are inside 
nurbs/ subdirectory: nurbs_curve_interpolators.wrl, 
nurbs_curve_interpolators.x3dv , nurbs_surface_interpolator.x3dv . 
Although they use view3dscene-specific CastleScript code, it may be 
required to rewrite it to JS to make them cross-browser.

Aside from that, everyone is welcome to report view3dscene bugs to our 
bugtracker on https://sourceforge.net/p/castle-engine/tickets/ . 
Reporting there a bug, with testcase attached, is the best way to have 
your problem fixed :)

Michalis