This question may have been asked many times as I did search before but I never found a right answer. I''ve been thinking about creating a game similar to that of Age Of Empires 2, and I am wondering how I should go out and do it. I have a lot of experience with OpenGL, and I enjoy using it. When I make my Iso engine I want to take advantage of the things that I have implemented using it (ie. Alpha blending, Particle systems, decals, picking) but I dont want to get off on the wrong foot here. Do ya hear me here? Just a couple more questions while I''m here... 1. What would be the best way to go about doing it? Doing a full 3D scene and just rotating the camera, or Ortho projection? I want to know from people who have experienced this sort of thing.. 2. What is the best method of occlusion for this type of view? I''m sure that OpenGL does the clipping, but I do still need to reduce the amount of polygons seen

I''m sure you''re going to get a barrage of "actually, if you use 3D it''s not really isometric because of the perspective distortion and blah blah blah" responses so I thought I''d chime in early with my limited experience...

I''d just go with full 3d, model the whole thing and have your camera fixed at a specific height & downward angle, allowing rotation around the Y axis of your world... that''s what we''ve done.. looks fine... but then rotation was important to us to create the level of world detail we want... if you''re making an RTS then maybe rotation isn''t important... in which case you may want to go with a bunch of pre-rendered sprites and use billboarding or projections or whatever they call it...

unfortunately I don''t have any clue on occlusion.. we haven''t got around to optimisation yet

but we''re using openGL and our goal is a 3D engine from an mostly ISO type perspective with limited camera control so if you want to share ideas or just discuss problems, send me an email..

just my $0.02

Yeah I know people are going to start ranting about 3D is not Isometric, etc. blah blah blah blah blah

I think I''ll do full 3d and just rotate around the world. I am clueless however on a good way to implement a map editor for this. I''m pretty sure that I will render the terrain through heightmaps, and texture it all with an equally sized texturemap.

Thanx

If you use a perspective projection rather than an orthographic projection, then you will have to scale your sprites too. This may or may not be an issue, depending on how your sprites are designed, and if you''re using sprites at all. Just something to consider.

I''m tired of this 3d isn''t isometric discussion...
In my own XP ISO engine the camera is locked to isometric point at default but it can be rotated and zoomed freely. In some point''s of the game I move the camera to first person view point when talking to other characters in the game.

In my opinion the engine is isometric when the view is at isomtric point moust of the time. It doesn''t matter what kind of method do you use for the ground, objects etc... for rendering.
I have found that the best way is using 3d models due to their flexibility. Example when my character carries weapon it isn''t just an diffrent model of the character carrying weapon but it is 3d model of weapon which is attached to the characters hand so that it stays there when cahracter moves or rotates. If I had used sprites then I should have made first anims of character running, shooting etc and after that I should have made those anims with it holding the weapon. That would have mean lot''s of work...

But still it''s your choice...
By using sprites the engine is faster to make but you(or the graphics artist) have to spend lot''s of time making those sprites.
By using 3d models the making of the engine uses more time but it pays of at the graphics stage.

You decide but before making any decisision look at some games using both of the methods and after that decide whihc suites your needs better....

ok let me add a few words too:
1.for me a 3d iso view is the good old orthographic projection.
I saw what diablo2 looked with perspective projection and I ran away as fast as I could... it looks kinda sick!
2.with ortho projection you can use nice sprites and they don''t change their resolution - so THE IMAGE QUALITY IS BETTER AS IT DOESN''T GO THRU ANY FILTERS! Most ppl doesn''t seem to realize it/care about it.
3.Using 3D models? Well why not making a 3d game? Using 3D models will decrease engine performace and it doesn''t look NEARLY as good as the real thing.
4.If you''re using an orthogonal projection then occlusion culling isn''t a subject as it''s trivial.

With best regards,
Mirek Czerwiñski
http://kris.top.pl/~kherin/

Iso is the look not the method.

Tombstone uses 3D models because it saves a large amount of memory and allows more freedom in what can be done. I can change the look of the character without creating more sprites.

As for decreasing engine performance...not really.

Ben

[Icarus Independent | Jump Down The Rabbithole | Tombstone: Vendetta ]

Lots of console iso''s are full 3d...

Surf on over to www.stainlesssteelstudios.com and look at some screenshots. It''s full 3d, and it''s by the same guy who wrote AOE.

EE may be tiled but it''s not ISO as it has a vanishing point.

Ben

[Icarus Independent | Jump Down The Rabbithole | Tombstone: Vendetta ]