Units not affected by invisible platforms

[NarGalloth]

Hi.

Well, the title already says what I need. How can I make a unit not be affected by invisible platforms?
I have a bridge with invisible platforms, so units can walk over it. However, I need some flying units to be constantly walking below the bridge. And if I have invisible platforms, they instantly go up when they reach the bridge. I need them to keep their flying height below the bridge.
Is this possible? I tried some things and they didn't worked...

Regards

 

[rulerofiron99]

Two methods, both of which are difficult, limited and not smooth:
- Set the flying units' heights to negative. If these flying units go beyond the bridge, their height will have to be changed. Note that you can't give a unit negative height, so if a unit "goes under" the bridge, you'll have to replace it with a unit that has negative initial height.
- Trigger the height of the units walking OVER the bridge. No matter how you do it, the units will "bump" a little when they walk on/off the bridge. You will then also need to trigger the units to be unable to walk off the sides of the bridge.

I made a map a while back where I attempted to add bridges that defenders can walk over and attacks can walk under (both ground units); I'll see if I still have it lying around somewhere.