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OpenGL What exactly is OpenGL for anyway?

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Allright, OpenGL is obviosly a powerful API, but it mainly makes graphics. I want to program games, not make graphics(?!?!?!?!?!??!) Why should I need to know OpenGL? I really dont quite understand that. If the programmer makes the graphics in opengl, what does a graphic artist do? Please, someone explain this to me. Maybe its because I havent learned much of OpenGL yet, though I currently am, while reading my book, I was thinking to myself, "Why should I have to do all this, I just want to make it say hey attack now, rip his head off, feed him to the rabid monkees, and through his body to the zombies on the fourth floor." Thats just a ridiculus example(lol) but I mean, I dont mind dealing with the graphics, I just dont understand then what a graphic artist is for. "He who fights monsters should look to it that he himself does not become a monster... when you gaze long into the abyss, the abyss also gazes into you."~Friedrich Nietzsche Edited by - kaiel090x on August 19, 2001 3:03:33 AM

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OpenGL is an API for showing graphics already made BY artists, it''s not like Photoshop or anything like that, it''s used to show triangles, textures, make effects and things like that, an artists doesn''t need to know how to program to make the graphics, but is you are going to use OpenGL you NEED to know how to program.

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Basically, a graphic artist has to make the graphics. The programmer then has to get the computer to display those graphics on screen. This is what OpenGL and other APIs (like DirectX) are for. A graphic artist can make a 2D texture or something within a graphics program. But to use that in your game, you have to have some way of displaying that texture.

I think you''ve confused two things. Programming games doesn''t have to do with making graphics, but rather, displaying graphics. That''s why you would benefit from knowing OpenGL. Without using OpenGL, or another API, you''d have to write your own software routines for displaying graphics.

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Hi, kaiel090x!
Judging by what you said it seems to do a mod for an existing game (-engine) like q3 or ut would be more what you should be looking into. When programming a mod you don''t have to mess with opengl or directx instead you can load your models and write in your code
model->ripHeadOff(targetModell); //(veeeeeerrrryyyy simplified ;-)
Hope you get what I meen. This way you can concentrate on creating your models an maps and only have to code the game logics not the graphics routines.

baumep

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Actualy I want to make 2d games in OpenGL and C++, I know C++ and I am learning OpenGL(well, I know a decent amount of C++, the extremely advanced stuff I am still learning). But, im better off reading a book and actually learning openGL then just taking tutorials on 2d, cuz they assume you know some of OpenGL anyway, plus they are hard to find. I didnt understand why I should need to make the graphics for the game a program, because if I did what is the point of having a grafic designer? But I understand now, and I just dont agree with it, but if its what I have to do to be a programmer, I will do it. Its not muhc a of a deal. THank you everyone for answering my question.
quote:
Original post by baumep
Hi, kaiel090x!
Judging by what you said it seems to do a mod for an existing game (-engine) like q3 or ut would be more what you should be looking into. When programming a mod you don't have to mess with opengl or directx instead you can load your models and write in your code
model->ripHeadOff(targetModell); //(veeeeeerrrryyyy simplified ;-)
Hope you get what I meen. This way you can concentrate on creating your models an maps and only have to code the game logics not the graphics routines.

baumep




"He who fights monsters should look to it that he himself does not become a monster... when you gaze long into the abyss, the abyss also gazes into you."~Friedrich Nietzsche

Edited by - kaiel090x on August 19, 2001 1:21:27 PM

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quote:
Original post by kaiel090x
I didnt understand why I should need to make the graphics for the game a program, because if I did what is the point of having a grafic designer? But I understand now, and I just dont agree with it, but if its what I have to do to be a programmer, I will do it.

Er, what''s to disagree with? Artists do the art. They are in charge of something looks. The programmer is in charge of how it acts. Objects move around the map and obscure other objects. This is tracked in code. Therefore the code has to decide how and where to draw things, and what to draw. It''s just the same with sprites: the artist draws the sprite, but the programmer still has to tell the program when and where and how to draw it.

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quote:

I didnt understand why I should need to make the graphics for the game a program, because if I did what is the point of having a grafic designer? But I understand now, and I just dont agree with it, but if its what I have to do to be a programmer, I will do it.



Um, kaiel090x, I don''t think you''re quite understanding this.

OpenGL is an API, interfaced to by C functions, which is used by programmers to communicate with 3D hardware, basically to draw triangles. The graphic designer will still make the graphics in a 3D modeller such as 3DSMax. As the coder, you have to write the code needed to load and draw the objects the artist makes, which is where OpenGL comes in (with the drawing, anyway, not the loading).

If using an API is a problem, you''d better start learning ASM.


www.elf-stone.com

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I am sorry if you didnt quite understandme correctly. I know OpenGL is an API. I know what it can do, and I know whats its for. I said in m last response that learning it really isnt much a problem for me. What I DIDNT(notice it is dont anymore) was why the programmer has to screw with graphcs, I understand it now, PROGRAMMERS LOAD THE TEXTURES INTO THE TRIANGLES/ECT WE MAKE. Then we can control the graphcs.
quote:
Original post by benjamin bunny
[quote]
I didnt understand why I should need to make the graphics for the game a program, because if I did what is the point of having a grafic designer? But I understand now, and I just dont agree with it, but if its what I have to do to be a programmer, I will do it.



Um, kaiel090x, I don''t think you''re quite understanding this.

OpenGL is an API, interfaced to by C functions, which is used by programmers to communicate with 3D hardware, basically to draw triangles. The graphic designer will still make the graphics in a 3D modeller such as 3DSMax. As the coder, you have to write the code needed to load and draw the objects the artist makes, which is where OpenGL comes in (with the drawing, anyway, not the loading).

If using an API is a problem, you''d better start learning ASM.


www.elf-stone.com



"He who fights monsters should look to it that he himself does not become a monster... when you gaze long into the abyss, the abyss also gazes into you."~Friedrich Nietzsche

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Guest Anonymous Poster
quote:
Original post by Galileo430
2D? Learn Direct Draw.

Lots of nice books out there on it.

I think that kaiel090x has the right idea, OpenGL is postable to just about every system instead of being stuck on Windows.

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Just my 2 cents I think Opengl does a great job of doing 2d its really easy to do and you can get some nice sfxs going on too and its portable like ya guys said .

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al right, all right... Ok. I KNOW (cleaer to say printf or cout in front for some of ya? lol) that i CAN(see C_A_N- Can- being able to) do 2d, and I know its WORKS just as welll as Direct Draw, but I dont know HOW to put 2D into the game. But, a very great person, the best guy in the world, lol, ShiningKnight told me hes makin a tutorial SO i dcided just to wait till than. Thank for trying to help me

"He who fights monsters should look to it that he himself does not become a monster... when you gaze long into the abyss, the abyss also gazes into you."~Friedrich Nietzsche

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Hmm Im a bit bored so I''ll put in some info here.

OK, now assume you have some sprites that you want to animate in 2D [your characters/fighters/backgrounds/weapons/etc]. Your graphics are already drawn.

You have these drawn out already in something like photoshop and they are bitmaps [or JPEGS or whatever.. they''re images in some form]

Now you have to have something that puts it all together. Your program in C++ calls OpenGL in order to draw the pixels to the screen.

In the case of 3D, OpenGL is actually calculating the position, lighting, texturing/etc for each triangle. It is converting from the XYZ coordinates you specify into actual pixels that are to be displayed on the screen.

In the case of 2D, OpenGL allows you to draw and animate your existing 2D sprites. It will load in the images you have made and move them around the screen based on the instructions you give it. It can layer images [like putting a character on top of a background] or blend images together [using transparancy/etc]. You can rotate/scale the images, and tons of other stuff.

OpenGL is not what you use to create the images, it is what you use to display the final result.

The graphics artist will make the content that OpenGL uses to display on the screen, but the programmer must tell OpenGL how to use that content.

Anyway, hope this helps.
~Dom C.
binary1230

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