Wide variety of 3D programming methods...

[Venom555]

I was wondering if all the methods like Octrees, BSP Trees, matrix multiplication(is that what it's called?), alpha blending and the such are really necessary for 3D games... what would be the point of all of those extra methods?

[SLH]

That's a very open question, and very tough to answer!

Matrix manipulation is used by all 3D gamess (well ok 99.99% of games), since it allows points (3D or otherwise) to be manipulated very quickly be graphics cards (since they are optomised to do (matrix) multiplications).

Alpha-blending is when you blend 2 or more images together, when dealing with textures you can give a texture an alpha level. By using alpha-blending you can make layered textures, which can greatly improve the image quality.

Oct-Trees and BSP-Trees are used to effectivly 'partition' a 3D environment. Some kind of structure like these is pretty much necessary for all but the simplest of games, since it's very inefficient to render the entire world every frame!

[Venom555]

Say I learned all the fundamentals of OpenGL... what more would I need to be able to program say a 3D World?

The only thing I've done in OpenGL + C, was create a texture mapped Car that looked like a shoe box, that could rotate all sides with the arrow keys.

[SLH]

If i were you i'd concentrate on the basics of a 3D world - the objects (walls, floor etc.).

Learning some sort of space partitioning algorithm (such as oct or BSP trees) would be good.

Later you could move onto making your world look nicer, with (multi/dynamic)textures and things like collision and physics.

[Halsafar]

SLH is dead on there, thats how I did it.
I created 3 engines to process a simple world you could zoom the camera around in....3 attemps... they where all pathetic compared to my current work.

Now I have full plush 3D worlds with rollings hills and near perfect collision detection... Still nothing to great. Sometime the hardest part is knowing good C++ techniques, making a game engine is not an easy task, I can't think of many software apps which pose such a challenge.

But a short answer to your Q, YES!!! You MUST learn all of that,.

[Venom555]

What about line stippling with 16 bit integers, and point and line antialiasing? Are those things also essential to OpenGL?

Oct-Trees and BSP-Trees are used to effectivly 'partition' a 3D environment. Some kind of structure like these is pretty much necessary for all but the simplest of games, since it's very inefficient to render the entire world every frame!

What if I had 'sectors' in my game, like a sector of a few rooms, or a piece of ground, and I would only render the current sector I am in every loop?