Scenegraph IO

Engines, Libraries and Tools Java 3D
#1

Has anybody else run into a problem with the scenegraph.io package dropping normals?

Here’s what I’m doing:

  1. Create a Switch containing 3 Shape3Ds with different LODs
  2. Recalculate all the normals on the Shape3Ds to smooth over seams.
  3. Add the Switch to a BranchGroup
  4. Write out the BranchGroup using the SceneGraphFileWriter.
  5. Attach the BranchGroup to a live universe.

So that all seems to work, everything displays fine, including the smoothed normals.

But then, I restart the program with a “load scenegraph” flag turned on:

  1. Read in the BranchGroup using a SceneGraphFileReader
  2. Attach the BranchGroup to a live universe.

The normals are messed up! They are not even the original (non-smoothed) normals, but something else entirely!

The rest of the geometry, including texture coordinates, appearance, etc. is fine – just the normals are clobbered.

Anybody else run into this problem? ???

Is anybody else actually using the Scenegraph IO utilities? ???

#2

I’m using the ScenegraphIO packages, but I have only used it for prelit textured geometry so I have not run into any problem with normals (a good extension to GeometryInfo would be a method that lets you change vertex format to get rid of unused info, like normals).

The known issues list for Java3D 1.3.1beta lists bug 4717595 (http://developer.java.sun.com/developer/bugParade/bugs/4717595.html ) as a problem with ScenegraphIO, but it does not seem to have the symptoms that you describe.