Is it at all possible to extend the Camera instance to create an orthographic camera?

And software-rendered Polylines, please?

Yet another attempt. This is based off of SkeletonDebugger. It's still not quite right:

     private void updateWeaponPos() {
SimpleVector o = weapon.getTransformedCenter();
SimpleVector d = getJointPosition(rightHand);
SimpleVector left = model.get(0).getXAxis();
weapon.translate(d.x-o.x, d.y-o.y+.1f, d.z-o.z);//d.x-o.x, d.y-o.y+.125f, d.z-o.z

//NOW ROTATION:
Skeleton skeleton = model.get(0).getSkeleton();

final int parentIndex = skeleton.getJoint(rightHandIndex).getParentIndex();
if (parentIndex != Joint.NO_PARENT) {
     Object3D bone = weapon;
     updateWeapon(bone, skeletonPose.getGlobal(parentIndex), skeletonPose.getGlobal(rightHandIndex));
}
     }
     private void updateWeapon(Object3D weapon, final Matrix start, final Matrix end) {
SimpleVector from = start.getTranslation();
SimpleVector to = end.getTranslation();
SimpleVector direction = to.calcSub(from);

weapon.getRotationMatrix().setTo(direction.getRotationMatrix());
weapon.rotateY((float)Math.PI+rotY);//rotY IS SO THAT THE WEAPON ROTATES ALONG WITH model.getRoot()
weapon.rotateAxis(weapon.getZAxis(), (float)Math.PI*.2f);
     }

Notes:
-Adding the weapon to the root of the character breaks the whole thing.
-I'm having to rotate the weapon by the same amount as the root because it otherwise doesn't chase the hand.
-It kind of looks right until you look straight at the hand and you see that the weapon is not facing the right direction during any given animation

Can I forcefully update it in order to have an item keep up with my character's hand?

On the other hand, this time it may well be a Java bug:

Why does array[idx++]+=“a” increase idx once in Java 8 but twice in Java 9 and 10?

https://blog.takipi.com/stack-overflow-answers-the-top-java-questions-we-didnt-know-we-had/

It works both ways, but it's getting displaced as it gets wider. Read that last version of thicken() and you'll see my many attempts to keep the center in the same place.

ClearRotation() doesn't do anything (and it shouldn't, since I interpolate the matrices of the lightsaber and the skeletal structure's hand in the loop). ClearTranslation fixed its initial position, thanks very much.

Now, I'm having a hard time keeping glow in the same place. I've tried every permutation of the following method of which I could think:

     public void thicken(final float deltaTime) {
SimpleVector[] vertices = this.getSourceMesh();
SimpleVector[] destination = this.getDestinationMesh();
final SimpleVector c = new SimpleVector(obj.getTransformedCenter());
float minX = Float.MAX_VALUE, minZ = Float.MAX_VALUE, maxX = Float.MIN_VALUE, maxZ = Float.MIN_VALUE;
for (int i = 0; i < vertices.length; i++) {
     SimpleVector v = new SimpleVector(vertices[i]);
     v.x *= (1f+deltaTime);
//      v.x -= deltaTime*.5f;
     v.z *= (1f+deltaTime);
//      v.z -= deltaTime*.5f;
     destination[i] = v;
     if (minX > v.x)
minX = v.x;
     if (maxX < v.x)
maxX = v.x;
     if (minZ > v.z)
minZ = v.z;
     if (maxZ < v.z)
maxZ = v.z;
}
this.updateMesh();
SimpleVector d = new SimpleVector((minX-maxX), 0f, (minZ-maxZ));
obj.translate(d);
// obj.clearTranslation();
// obj.calcCenter();
// Glow.moveTo(obj, c);
// Glow.moveTo(obj, d.calcSub(c));
     }