BulletConvexHullShape debug edges

I am setting a self-made convexhull geom to BulletConvexHullShape

    bulletcvxhshape = BulletConvexHullShape()

Then, I showed it using DebugNode.
The result is as follows.

The wireframes does not look like a convex hull.
The following figure shows a nodepath generated using the same geom. It is very different from the BulletConvexHullShape under the DebugNode.

Did I miss sth…?

Here is another example. This object includes several nodepath. Each of them is made into a BulletConvexHullShape

The tip looks good, but the middle part has lots of weird edges.
I am quite sure they are not part of the convexhull.

Maybe just DebugNode creates its own geometry.

The weird edges are probably just part of Bullet’s debug rendering. I think they should not affect the physics behaviour.

Thanks a lot!
According to the example, it seems the BulletConvexHullShape accepts a concave Geom and automatically compute its hull. Is that true? The weird DebugNode rendering made it difficult for me to observe the correctness… Right now I am computing a convexhull explicitly outside.

I have gave up using BulletConvexHullShape, please refer to my new question 27022 for updates. I will close this session.