What are good ways to handle collaboration on a map?

I’m starting work on a map and I’m going to have other people working on different parts. Is there some automated way to handle merging changes between different versions if, for example, two people start with the same VMF on their local computer and both make changes independently of each other? I thought of using a version management system at first but wouldn’t one person be overwriting the other’s changes when they uploaded their version?

Yes, you can’t “add” a piece of map, you replace your map with someone else his, unless the map name is diffrent, and you use changemap to use the part someone else made.

You can just copy his work into yours.

But he means, a program wich merges them together, not by hand…

You could work on it alone? Probably the best solution.
There isn’t anyway of merging changes between vmfs, although you could set up an SVN repository or something, and then work on the map when the other person isn’t. Copying between vmfs can wind up with the copied sections off grid, from some unknown reason. Moving them back on is almost impossible.

Can’t you open the vmf in a text editor, find one of the offgrid brushes in the corner of pasted section, get how far off grid it is, then back in hammer do the transform > move and move it back onto the grid.

Didn’t think of that, but it would become tricky because it often seems to be the cause of an odd bug where the point which is snapping to the grid when you are moving the brushwork becomes off grid and not in a logical place, leading to it snapping to the grid leaving the brushwork off the grid. It doesn’t make things easy at any rate.