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JosephParrilla

OpenGL Best openGL resource

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Hey Guys,

So I know that the NeHe website is very popular for learning openGL. Ive done some reading and it seems like there were major changes regarding a fixed function pipeline vs shaders, etc. Im not exactly sure of the details. My question is, is the info on NeHe up to date for the version of openGL I should be focusing on, or is there a better resource? I am eventually accessing openGL thorugh LWJGL, but I am probably going to learn through C++ since its easier to find examples in it. I can always use Java and LWJGL later, its basically the same. I am basically looking for beginner tutorials, which are easy to find, but I dont know enough about what version of openGL I should find tutorials on. I wouldnt even know if I was using the right one or not since I really dont know the difference.

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NeHe is deprecated, in newer OpenGL you have no fixed function pipeline and have to write shaders yourself. A lot of the old API calls are removed in OpenGL 3/4, which means that you have to do more of the work yourself, like creating your own matrices etc...

There is a large tutorial on it [url="http://arcsynthesis.org/gltut/"]here[/url] (haven't checked it out myself, though. ) You should also check out the [url="http://www.opengl.org/sdk/docs/man4/"]OpenGL documentation[/url], which I use a lot myself since it tells you what the different API calls do.

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[quote name='fluffybeast' timestamp='1310505287' post='4834508']
NeHe is deprecated, in newer OpenGL you have no fixed function pipeline and have to write shaders yourself. A lot of the old API calls are removed in OpenGL 3/4, which means that you have to do more of the work yourself, like creating your own matrices etc...

There is a large tutorial on it [url="http://arcsynthesis.org/gltut/"]here[/url] (haven't checked it out myself, though. ) You should also check out the [url="http://www.opengl.org/sdk/docs/man4/"]OpenGL documentation[/url], which I use a lot myself since it tells you what the different API calls do.
[/quote]

Ahh I figured that much, the dates on the articles are really old. I cant get that link to work, are theyre any books/tutorials that cover the new stuff? I dont want to learn information that isnt up to date. What about those big openGl bibles on Amazon?

I must say Im going to need more than just the API documentation. Im really new to graphics programming so I would prefer some explanations. I dont need my hand held, but a nice organized tutorial with examples and explanations would really help.

I can probably find this stuff myself, so what exactly is the difference between the old and new openGL? If I know the difference, I will have an easier time knowing if a particular tutorial I find is outdated. Im sure there are a ton out there, I just dont want to use an old one.

EDIT: That link is fine, just blocked at my job.. its categorized under PORN lol... strange.

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A general rule of thumb is that if a tutorial contains calls to glBegin, glEnd and/or any of the glTexEnv functions then it's old and you should avoid it. There's a slight grey area where OpenGL made a transition from old to new (1.5 with extensions, 2.0, 2.1) which can muddy things a little. A danger is that you may find a few such tutorials or resources and end up using a somewhat outdated API that looks on the surface as if it [i]could[/i] be new-style, but in reality has since been superseded. Have a read of the arcsynthesis link posted above; it is really quite good and gives some background info which is written a lot better than I could do. Specific details on differences in how old vs new operate probably won't make sense to you right now as you'll need some grounding in 3D graphics terminology to understand such an explanation.

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Wiki it

[url="http://www.opengl.org/wiki/Main_Page"]http://www.opengl.org/wiki/Main_Page[/url]

Here's the reference pages

[url="http://www.opengl.org/sdk/docs/"]http://www.opengl.org/sdk/docs/[/url]

Cheers

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[quote name='mhagain' timestamp='1310508670' post='4834538']
A general rule of thumb is that if a tutorial contains calls to glBegin, glEnd and/or any of the glTexEnv functions then it's old and you should avoid it. There's a slight grey area where OpenGL made a transition from old to new (1.5 with extensions, 2.0, 2.1) which can muddy things a little. A danger is that you may find a few such tutorials or resources and end up using a somewhat outdated API that looks on the surface as if it [i]could[/i] be new-style, but in reality has since been superseded. Have a read of the arcsynthesis link posted above; it is really quite good and gives some background info which is written a lot better than I could do. Specific details on differences in how old vs new operate probably won't make sense to you right now as you'll need some grounding in 3D graphics terminology to understand such an explanation.
[/quote]

Yes, but even when you reach shader land (GL2.0 and above), there are some big differences.
With GL 2, you can use built-in attributes, built-in varyings, built-in variables and with fixed function parallels like glLoadMatrix and other matrix calls and glTexGen, glLight, glTexEnv, glMaterial, glColor.
With GL 3.0, 3.1, 3.2, 3.3, further changes came along. You have "core context" and "forward compatible context".
GL is a rather complex beast. Try to find some GL 3.3 tutorials which cover "forward compatible context".GL 3.2 would be fine as well as long as you use VAO everywhere. GL is pretty much stabilized now.
Let's hope they get rid of the bind to modify issue in GL 4.2

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Friendly advice: Take a look at proposed tutorial, or even better - grab some good book!

- OpenGL ES 2 Programming Guide is an excellent one.

- OpenGL Superbible 5th Edition is also great (but with too many basic stuff for my taste).

- OpenGL Shading Language 3rd Edition - great book but not for beginners.

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[quote name='Aks9' timestamp='1310587793' post='4834971']
Friendly advice: Take a look at proposed tutorial, or even better - grab some good book!

- OpenGL ES 2 Programming Guide is an excellent one.

- OpenGL Superbible 5th Edition is also great (but with too many basic stuff for my taste).

- OpenGL Shading Language 3rd Edition - great book but not for beginners.


[/quote]

The superbible was the book I was considering. It says it covers up until version 3.3, is that up to date enough?

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Avoid deprecated functionality.

One thing that will make everything easier is if you try and create a framework as you move along,

i.e.

I created an object with hard code,
Then I created code to make the object for me,
Now I can have hundreds of objects on screen.

I created a shader\program object with hard code,
Then I created code to do all the compiling, linking, for me.
Now it's much easier for me to make shaders.


Just START SLOW, Don't move on until you understand something.

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[quote name='joeparrilla' timestamp='1310588819' post='4834979']
The superbible was the book I was considering. It says it covers up until version 3.3, is that up to date enough?
[/quote]

Yes!


The only "fancy" thing that is missing is - the tessellation shaders (OpenGL 4.0).

There is also some other stuff in GL 4.0/4.1 but they are not crucial for understanding main concepts.

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[quote name='Aks9' timestamp='1310589420' post='4834983']
[quote name='joeparrilla' timestamp='1310588819' post='4834979']
The superbible was the book I was considering. It says it covers up until version 3.3, is that up to date enough?
[/quote]

Yes!


The only "fancy" thing that is missing is - the tessellation shaders (OpenGL 4.0).

There is also some other stuff in GL 4.0/4.1 but they are not crucial for understanding main concepts.


[/quote]

Gotcha, I think thats gonna be the one then. It got pretty good Amazon reviews.

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I like this one:

http://duriansoftware.com/joe/An-intro-to-modern-OpenGL.-Table-of-Contents.html

It was quite easy to follow, though I had already used some fixed functionality before.
I'm not sure if it's easy to catch for a starter, but at least it states no previous OpenGL experience is required...

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If I can just add a two bits of info that could help you greatly while trying to understand what is wrong with the programs you are going to make:
1) OpenGL is a state machine. Always keep this in mind, remember to bind objects before you attempt modify them, and don't bother trying to use OpenGL across multiple threads (single thread for all OpenGL operations).
2) Use gDEbugger to quickly identify errors in your OpenGL calls, and to easily view the current OpenGL state (textures, shaders, variables, bound objects etc.)

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I've read often that the SuperBible 5 is really biased toward the author's GLToolKit or whatever its called. I understand what they were going for in order to introduce graphics programming, but its an OpenGL book, I don't really see the logic in wrapping OpenGL. Unless of course the ToolKit is built and explained during the book's progression.

I think, if what I've read of the SB5 is true, that, maybe a better route (besides the two ebooks posted earlier which are very good,) is something like the Orange Book(OpenGL Shading Language) and OpenGL ES 2.0 Programming Guide.

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[quote name='The_Doc' timestamp='1310751549' post='4835730']
I've read often that the SuperBible 5 is really biased toward the author's GLToolKit or whatever its called. I understand what they were going for in order to introduce graphics programming, but its an OpenGL book, I don't really see the logic in wrapping OpenGL. Unless of course the ToolKit is built and explained during the book's progression.

I think, if what I've read of the SB5 is true, that, maybe a better route (besides the two ebooks posted earlier which are very good,) is something like the Orange Book(OpenGL Shading Language) and OpenGL ES 2.0 Programming Guide.
[/quote]

yes most of the negative reviews say this.... which totally confuses me. If its an openGL intro book, why in the world would they wrap openGL and teach that? It doesnt make sense to me.

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Exactly.

I guess it may be a misunderstanding. That is, perhaps the reviewers mean that the authors spend 7 chapters DEVELOPING the GLToolKit (the ins and outs) instead of going straight to GLSL. But that would mean the tool kit has shaders in it, which leads me to think they are indeed just black boxing the whole thing. I was hoping someone here had read it and could shed some light on it.

The two ebooks linked, I think, would do a good job of filling in the holes the SB5 would inevitably leave. So, I think it would still be a safe investment, I'm just boggled as to how a thousand page book would feel the need to approach the material that way.

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Nothing like suggesting something you yourself aren't willing to do, [i]but [/i]I'll go ahead and do it anyway...

It'd be great if someone went and rewrote the NeHe tutorials using only the OpenGL 3+ core profile only. I'm sure it'd immediately become a very popular site.

(By the way, I completely agree with the last couple posts. It understand why it happens, but it's frustrating when tutorials, books, lessions, etc. develop a framework or toolkit when they claim to be about learning the core API. Sure, to get to some advanced features you'll need to reuse some code, but limit it to functions, not frameworks - and write out the API calls full in when possible!)

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