I wanted to know if there is any way to detect if there is walkable null vs. actual land at a location.

The reason I wanted to know is that I wanted the characters in my map to have the ability to spawn a "turret gun" underneath them, but it doesn't work on space terrain, so I just replace the space with null and we're good. However, one of the characters is an overlord and I don't want him dropping on what is supposed to be space.

So if I knew where he was dropping was null terrain, I would constantly order the units back into the overlord or something.

Help

There's no easy way I immediately see. In short, no, there's no real way to detect walkable null from actual land. Any methods to do so would consume several locations and/or units.

First option: Create large locations over the walkable null and a small location locked on the overlord (the small location should only have ground flags checked). If a unit is brought to both the null location and the overlord location, you can run the AI script to order them back inside the overlord. Turret guns shouldn't be effected by this AI script, but I haven't tested it, so you may want to check that. The downsides: It can use several locations, and if you have regular units that CAN go on space (excluding air units), they will be effected by this trigger. Also, if there is more than one overlord (per player), centering locations onto them may prove difficult.

Second option: Place Player 9 (or another player) burrowed lurkers (or another unit) on the walkable null. You can space them out quite generously and put a large location over the overlord (again, have the location only have ground flags checked in its properties). Then, if a lurker is brought to the location, it detects that the overlord is over walkable null. Downsides: It can use a lot of units, depending on the size of the walkable null. Again, centering locations onto multiple overlords owned by one player will be difficult.

If it matters, one of the characters is an Arbiter (which could Recall stuff onto Null), and all the Protoss characters (scout, corsair, carrier, arbiter) are able to create Reavers at their location.

Also, there is a max of one of each character, so centering wouldn't be a problem.

What terrain height is Null? Low, Medium, or High? Or does it change for each Null tile?

EDIT: Oh yah, I'm working on this map with Madroc, if you're wondering.

And this is supposed to be allowed? If so, the AI triggers would only be active to the player with the overlord, and won't affect other characters on the null. If not, you can use similar detection tricks to try and stop these from occurring.

Null tiles are considered low height only.

Likely we'll just limit the use of low terrain to null and anything that we think is necessary, but with a location around that low area to distinguish it from the null.

It's a suboptimal way to detect the null because we'll need to limit the areas of low (besides null) to the number of extra locations we'll have (which probably won't be many).

Thanks for posting. If anyone else has any ways to detect null other than the one i described, please post!