Best methodology for symmetrical maps

[SaltyPapi]

Hi, I'm working on my first map, working Title: koth_waterworks, and I'm looking to make it a mirrored koth map. I've already figured that it'd be best to only build one half of the map for the most part, and then mirror it to make it playable (with all of the gameplay logic and spawns, etc.) This, I think, would work fine for incremental changes, but I'm worried about larger, sweeping changes, which would involve a larger amount of map geometry; adding a small block or prop, vs completely redesigning an area. I'm wondering about some kind of meta-methodology that would work best to keep everything neat and tidy throughout the development process. Would this same methodology work for maps without a clean, straight seam between halves, i.e. cut straight through without zig-zagging? What about rotationally symmetrical maps?

Thank you for your help.

 

[Cyberen]

I made a symmetrical map and I did the symmetry part like this:

1. Made one half, walled it off with a skybox and tested that half.
2. Then when I was satisfied, I selected everything, copied it as a group, making sure it was easy to snap it to the grid (either with a big skip box around it or just being easy to copy) and rotated it or flipped it.
3. Once the two halves are aligned, I would fix wrongly-flipped props and stitch together the middle if there's displacements.
4. Hammer++ has a tool where you can merge two brushes together if the result is convex, if you like.
5. If you're worried about redoing it, you can just make the copied side its own visgroup.

For adding additional details or redoing certain walls, delete the old walls and then highlight the new stuff with a big skip brush with a corner at the world origin. Copy and group, then flip it/rotate it around.

 

[Zeus]

What I usually do is define a line of symmetry, it doesnt have to be straight across, but where the stuff meets in the middle. basically using the technique crash talks about with a big skip brush, it should be easy to just clone one whole size and rotate it around

You can obviously mirror it using ctrl + L if you want it to be mirrored instead.