As people may know, I'm working on a RTS entry for 4E4. The basic idea is for it to have a high-angle view similar to TA, C&c, WarcraftII etc. But I can't quite get a decent camera/projection figured out. I'm using a non-orthogonal projection matrix currently but I can't get the isometric look I think I want, without the user being able to see over the edge of the world, hill-tops being very close to the camera, minimap showing wrong part of the map etc. Does Total Annihilation (as the only proper 3D RTS I played much) use orthogonal projection or what - I haven't go it installed any more!

The backgrounds in TA were simply tile based if my memory serves
me well with units / trees etc being rendered in real time, these
would have used orthogonal projectection.

you could probably use a vertex shader to simply move the z position
by a percentage of y to get a simular feel to the graphics assuming your
looking directly 'down' on the field of play

Hope it helps

Mark

No, TA had proper 3D terrain. But they got the view looking just like flat isometric games.
If I use an orthogonal projection to a 3D terrain like that, what will it look like?

Using an orthogonal projection should give you an effect just like what you see in TA. Other 3D games such as Warcraft 3 use a perspective projection, which also works pretty well.

If your interested in exactly how the terrain in TA was implemented, then MButchers is right - the TA terrain was pre-rendered onto tiles (it was way too detailed at the time to actually be rendered in real time). It's just that units driving over it moved logically as if it were actually 3D.

I'd never have guessed that - they must have implemented it very well!