I hand built a TriangleFanArray shape, and I want to be able to view it
from below and above.  How do I set the normals so I can see it from
above and below?  (I tried making two objects, one with normals up and
one with normals down, yet both objects will only be shown if I look
from above them???)

Sample code:

int numOfTriangles = 24;
int format = GeometryArray.TEXTURE_COORDINATE_2 |
GeometryArray.COORDINATES | GeometryArray.NORMALS;

...

int[] fan_counts = { numOfTriangles+2 };
TriangleFanArray trisUp = new TriangleFanArray(numOfTriangles+2,
format, fan_counts);
TriangleFanArray trisDown = new TriangleFanArray(numOfTriangles+2,
format, fan_counts);

...

for(int triangles = 0; triangles <= numOfTriangles; triangles++)
{

...

// Set the vertices
verticesUp[verticeIndex]    = x;
verticesUp[verticeIndex+1]    = 0;
verticesUp[verticeIndex+2]    = z;
verticesDown[verticeIndex]    = x;
verticesDown[verticeIndex+1]     = 0;
verticesDown[verticeIndex+2]     = z;

// Set the normals
normalsUp[verticeIndex]     = 0;
normalsUp[verticeIndex+1]   = 1;
normalsUp[verticeIndex+2]   = 0;
normalsDown[verticeIndex]   = 0;
normalsDown[verticeIndex+1] = -1;
normalsDown[verticeIndex+2] = 0;

// Set the texture coords
textureCoords[textureIndex] = (float)(theta2 * .5 + .5);
textureCoords[textureIndex+1] = (float)(theta* .5 + .5);

...

}

// Set the top ring
trisUp.setCoordinates(0, verticesUp);
trisUp.setTextureCoordinates(0,0,textureCoords);
trisUp.setNormals(0,normalsUp);

// Set the bottom ring
trisDown.setCoordinates(0, verticesDown);
trisDown.setTextureCoordinates(0,0,textureCoords);
trisDown.setNormals(0,normalsDown);

topRing = new Shape3D(trisUp, createAppearance(texture));
botRing = new Shape3D(trisDown, createAppearance(texture));

TransformGroup result = new TransformGroup();
result.addChild(topRing);
result.addChild(botRing);
return result;