subtractive to additive?

[Hawkwolf]

This is more of a curiosity then a problem. I am wondering if there is a way to convert a subtractive map to an additive one?

See I am used to subtractive and so I made an outdoor map using sub. Today i was looking at the various threads here and one of them mentioned the advantages of using additive for outdoor maps and this got me thinking about making it additive.

[bclagge]

Did you take a giant hunk out with a subtractive brush, put in a skydome, and then began adding like it was an additive map?

If so, just select everything in the map and press CTRL-C to copy. Start a new additive map and press CTRL-V to paste. Now delete the giant subtractive brush and you should be set.

[Setheran]

A safer bet would just be to delete/shrink the gigantic additive cube that the editor automatically creates when you choose to make a map in "subtractive" mode. If you zoom out far enough and move to the very edges of the grid you should find the cube's edges (or possibly try switching the perspective viewport to wireframe mode to spot it easier), and then you can either delete it and make a smaller one, or just try shrinking it down to the edges of the subtractive parts of your level.

[Vicious3745]

Ya, Copy and past everything into an additive map, but you're gonna have to convert the CSG of every brush to it's opposite, i'm sure.

And ya, for some reason, Additive Space builds faster and is less processor hungry than Subtractive space for some reason.

[Hawkwolf]

EDIT: Ok shrinking the big add box did the trick. Thanks, it cut my light build time almost in half.

[bclagge]

Select a brush. Press CTRL-P to make your builder brush the same as the selected brush. Delete the selected brush. Add or subtract with the new builder brush as necessary. Easy only applies to a single brush. Doing a whole level won't be quite so easy.

[SpY]

Just curious, why is an additive map better for outdoor maps? Does creating it this way improve performance in game?

[Odedge]

Just curious, why is an additive map better for outdoor maps? Does creating it this way improve performance in game?

An additive map doesn't have that huge additive brush that is there by default in a "subtractive" map. That is why Hawkwolf noticed a shorter build time when he resized it.

In addition, if you are doing a map like DM-Sanctuary, an "additive" map is better as you are usually inserting buildings and larger objects rather than carving out rooms. You also need to place a sky dome of sorts and doing that with the default "subtractive map" is a pain!

[SpY]

Ok I am making an outdoor map now, but I was creating as a subtractive map. I'm just wondering if there's a in-game performance advantage to doing it that way (additive better FPS?, etc..) - ty

[Odedge]

Ok I am making an outdoor map now, but I was creating as a subtractive map. I'm just wondering if there's a in-game performance advantage to doing it that way (additive better FPS?, etc..) - ty

Not really. The biggest concern is your build time with default subtractive maps because of the really big additive brush.