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6 comments, last by oler1s 16 years ago
ok theres something i am having a very hard time grasping. What is OpenGL. and what is for example, Irrlicht? do they do the same thing? what's easiest to learn? i dont really understand the differences, can someone help? --thank you
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Irrlicht is a complete 3D engine, whereas OpenGL is just a 3D API, Irrlicht has an option to use OpenGL to do it's rendering.

Another big difference is OpenGL does just graphics where Irrlicht provides means to get input as well.
OpenGL is a language-independent library available (among others) in C and C++. Its purpose is to provide access to low-level primitives for accelerating the rendering of 3D images using existing hardware accelerators. The primitives mostly involve the manipulation of image and polygon data and the execution of render instructions.

Irrlicht, like many other 3D engines, is built on top of OpenGL (and similar libraries) to provide additional functionality. While they allow less freedom than OpenGL itself, they provide shortcuts for a large set of features which you would have to write yourself otherwise (almost everything on this page, for example).

As a whole, if you're starting out and intend to make a game, using a 3D engine is a superior alternative to developing your own solution in OpenGL.
thanks for the fast response.

ok so like, opengl is a way to display stuff, where as Irrchlit is away to utilize opengl and other things for ease??

Quote:Original post by pavel989
thanks for the fast response.

ok so like, opengl is a way to display stuff, where as Irrchlit is away to utilize opengl and other things for ease??


You're in luck: today is Handy Metaphor Day!


OpenGL is like a highway. Irrlicht is both the highway *and* an automobile to drive on it.

Sure, you can build your own car, but it's just so much easier to start with a ready-made car if you're still learning to drive. You can graduate to kit-cars and even metallurgy and automotive engineering later, if you find that sort of thing interests you. (Most people don't care how the magic horse-less carriage works, as long as it goes forwards, backwards and around corners as expected.)


Game development is exactly the same, only different.
Sean Timarco Baggaley (Est. 1971.)Warning: May contain bollocks.
Quote:ok so like, opengl is a way to display stuff, where as Irrchlit is away to utilize opengl and other things for ease??
The way you phrase it sounds like you don't quite get it.

Any kind of graphics is done with your graphics card. From the developer's point of view, you want some kind of API and library that allows you to work with the graphics card. More precisely, you want to use the graphics card to draw something on the screen. The graphics card manufacturers along with a number of companies agreed on a standard. One of the things the standard does is define an API that you can use in C programs for graphics.

That means that either OpenGL or Direct3D (which the graphics card support) have to somehow be used when you want to work with the full capabilities of the graphics card. Now, you could some other library, say Irrlicht. But if Irrlicht clames to have graphics support, that means it under the hood, it uses either OpenGL or Direct3D.

When you compare one game to another, there's a lot of similar code in terms of what needs to be done. Everything from debugging to handling image and model files. Then graphics related code, like particle effects, or text drawing and effects on the text. Shadows, etc.

You see, OpenGL just defines a base API for working with the graphics card. So you have to write a lot of code to actually have a game or something like that. As you might imagine, various groups and companies spend time writing an engine, basically a large library of code that does all of that for you. That means that instead of spending large amounts of time writing code to draw shadows and create water effects or whatever, you focus on writing the game code.

Do you understand better now?
Quote:Original post by oler1s
Quote:ok so like, opengl is a way to display stuff, where as Irrchlit is away to utilize opengl and other things for ease??
The way you phrase it sounds like you don't quite get it.

Any kind of graphics is done with your graphics card. From the developer's point of view, you want some kind of API and library that allows you to work with the graphics card. More precisely, you want to use the graphics card to draw something on the screen. The graphics card manufacturers along with a number of companies agreed on a standard. One of the things the standard does is define an API that you can use in C programs for graphics.

That means that either OpenGL or Direct3D (which the graphics card support) have to somehow be used when you want to work with the full capabilities of the graphics card. Now, you could some other library, say Irrlicht. But if Irrlicht clames to have graphics support, that means it under the hood, it uses either OpenGL or Direct3D.

When you compare one game to another, there's a lot of similar code in terms of what needs to be done. Everything from debugging to handling image and model files. Then graphics related code, like particle effects, or text drawing and effects on the text. Shadows, etc.

You see, OpenGL just defines a base API for working with the graphics card. So you have to write a lot of code to actually have a game or something like that. As you might imagine, various groups and companies spend time writing an engine, basically a large library of code that does all of that for you. That means that instead of spending large amounts of time writing code to draw shadows and create water effects or whatever, you focus on writing the game code.

Do you understand better now?


ok so like, Irrchlet is kind of like an extension to opengl or Directx/3D, with a bunch of extra stuff to make programming easier?
Quote:Irrchlet is kind of like an extension to opengl or Directx/3D, with a bunch of extra stuff to make programming easier?
It's not an extension. If you write a 3D game, is your game an extension of OpenGL? Of course not. You can't really extend OpenGL anyway.

It's an engine. OpenGL and Direct3D happen to be used for graphics.

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