Why do you consider it "obvious" for an isometric engine to be 2D? Even if it is rendered in a fixed view, and using tiles and sprites, there are no reasons why the world cant be represented in full 3D. In fact, this makes a lot of things easier - particle systems and life-like physics included.

/Niels

I don't know about everyone else in this forum, but internally, my world is stored as a 3D world. It is only when it's drawn to the screen that there is a transformation from 3D to 2D/pseudo-3D. I'm sure your also doing the same thing but didn't phrase it correctly or I simply misunderstood you.

As far as implementing a particle system where every object has mass so that gravity can act on it, then you will want to store your objects in a 3D world. If you are storing it any other way, then you have a very very hard mission in front of you. Every object should contain a ordered triple (X, Y, Alt). The values of the triple should be relevant to your map system and not pixel location. Normally what I do is have X, Y be the 2D position on the map and Alt be the altitude off the ground.

With these three values, you can perform gravity functions using real physic functions (if you want, but it is slower) or basic fake-physics functions (which aren't as accurate as real physics functions but are faster). That's your call.

Good Luck.

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Dino M. Gambone
http://www.xyphus.com/users/dino

Good judgement is gained through experience. Experience, however, is gained through bad judgement.

well, i'm trying to learn 2d to the extents before i move on to 3d. but if i did decide to store my game data as 3d, would i use D3DIM to display it, or what? i don't want to make models for everything, either. is there a way that i can do everything in 2d, like i have, but just use some 3d for certain things (i.e. particle systems, flying objects, etc...)

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_________________Gecko___

Storing data in 3D means storing all three dimensions of the object (x, y, z). It has nothing to do with rendering the object.

i want to add a realistic particle system into my iso engine, but obviously my engine is 2d. my engine has an approximately 45 degree angle relative to the plane of the land, so how could i calculate each particle to have gravity from that vantage point?

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_________________Gecko___

You can still use pre-rendered images to display the data. Storing the data in 3D simply means that... the data is stored in respects of an (X, Y, Z) point instead of a ordered pair (X, Y) or any other method you can thing of. I personally prefer it simply because it gives you many more options. There are drawbacks, as with everything. The main one being that it can get complex if not done properly and the ordered triple (X, Y, Z), or (X, Y, Alt) in my case, needs to be converted to a pixel point on the screen. This isn't hard at all, it's just another thing to think about.

Good Luck.

PS. Why don't you check out some of the documentation at my web page (http://www.xyphus.com/users/dino/). It may help you in this situation. I know Tanstaafl enjoys them.

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Dino M. Gambone
http://www.xyphus.com/users/dino

Good judgement is gained through experience. Experience, however, is gained through bad judgement.