using dynamic index with static vertex-array with VBO// Normals


I have a little question concerning VBO’s.
I create a VBO for my vertices with ARRAY_BUFFER_ARB. this buffer includes shared vertices. Now I have frequent changes of the faces, but always with the same vertices (as loaded in the array). some weren’t drawn because some faces get bigger or so.
So have I to use a ELEMENT_ARRAY_BUFFER which I have to refill every update or can I send the pointer to my index-array (int* size=number_of_vertices*3, Triangles) like I know it from glDrawElements()?
means, the vertices are in the Video-memory in a VBO, only the indices (the indices array) is transfered over the bus when calling glDrawElements()?

and what with normals, when using indices?
they’re changing too due to the fact the faces change…how to do this? I mean, I create a normal-array every frame, parallel to creating the index-array.

hope someone can help!

best regards,


Using regular index arrays with VBO vertices works just fine. Just use glDrawElements as usual passing the pointer as the last argument.