Removing unused vertices

[Dal]

Does anyone know a way to remove unused vertices in a mesh without breaking the indices? I guess i need some kind of function that can delete vertices from an array and remap all the indices to the new array locations for the remaining vertices. Does something like that already exist?

[adam]

My first thought is:  Why do you need to do this?

[Dal]

3 hours ago, adam said:

My first thought is:  Why do you need to do this?

For my terrain implementation... it creates the vertices for the whole terrain, then creates triangles only for the ones that are actually needed for the current LOD.
The theory is the verts will be set only once, and just the indices need to be updated, but it still seems to be too heavy so I want to try pushing only the currently used verts instead to see if that improves performance - but if I remove vertices from the array it will break the indices order.