public IndexBuffer getIndexBuffer() {
        VertexBuffer vb = getBuffer(Type.Index);
        if (vb == null) {
            return null;
        }

        return IndexBuffer.wrapIndexBuffer(vb.getData());
    }
Get the index buffer for this mesh.
Will return <code>null</code> if no index buffer is set.

@return The index buffer of this mesh.

@see Type#Index
jme3-core/src/main/java/com/jme3/scene/Mesh.java