6 ms·

Casual Introduction to Low-Level Graphics Programming

137 points by deafcalculus 10y ago

posterboy 10y ago
js;dr: the page doesn't render without javascript.
- Zecc 10y ago
  But think of the important reasons why this page requires JavaScript: - - -
- Zecc 10y ago
  Looking at the page's source code you can actually see the whole text there. Thrice: inside the `content` attributes of `<meta property="og:description">`, `<meta itemprop="description">`, and `<meta name="twitter:description">`. The `content`attribute of `<meta name="description">` is empty. A missed opportunity.
- douche 10y ago
  I'm really not a fan of this Medium-ization of programming blogs. I find this much harder to read than something more crude and basic, like, e.g. http://lazyfoo.net/tutorials/SDL/index.php http://lazyfoo.net/tutorials/SDL/index.php - static html, no JS (aside from the obligatory analytics, Adwords, and social widget throw-ins), high-contrast, no-nonsense.
  - BoorishBears 10y ago
    Man lazyfoo, that takes me back... I remember extending what I learned in the series of tutorials into a tiny Windows/Android cross platform demo a few years ago to get familiar with NDK
- joshkpeterson 10y ago
  Can we stop making every thread about this? We get it. You use noscript. COOL.
mrspeaker 10y ago
Excellent introductory post! There's so much to digest when you start playing around with things like OpenGL that you quickly get lost in the details... just memorizing things ("now for some reason I have to type "bindBuffer"). It's hard to build up a mental model for WHY you're doing all the steps. This gives a great bigger picture overview! (though, the next step is still the ocean of nitty-gritty details ;)
melling 10y ago
I've got a list of computer graphics resources on Github: https://github.com/melling/ComputerGraphics/blob/master/README.org https://github.com/melling/ComputerGraphics/blob/master/READ...
nightcracker 10y ago
I disagree with the introduction of the article. Low-level graphics programming is incredibly math intensive, and a solid understanding of trigonometry, linear algebra and discrete math is __required__ to be succesful in it. When I say discrete math, I mean fundamental understanding of how data is represented, and how you can interpret data as you please. E.g. using textures to store depth maps or even sound data, IEEE754 floats, etc. There are many areas of design and 3d graphics that do not involve math, but to claim that low-level graphics programming doesn't involve a lot of math is disingenuous and harmful.
- noobermin 10y ago
  I think they meant most graphics programmers who don't go deeper than the API know much math, unfortunately. It fits her narrative, say "most graphics programmers don't need math" but then goes to demonstrate how much geometry is relevant to low-level graphics.
aj7 10y ago
Does this person know anything about graphics, or is this some sort of creative writing or reportorial exercise? How can one introduce vectors without the word "direction"? How can one so thoroughly screw up the introduction to illumination?
- okatsu 10y ago
  Calm down. Stephanie has worked at Oculus and Unity and continues to do contract work in AR/VR while running a two-person company with Rich Geldreich from Valve. I have some problems with the post as well but the author's knowledge of graphics is not at stake here.
- psyc 10y ago
  When you write an article, and John Carmack responds with a correction, you're probably not actually doing too badly.
  - monkeyshelli 10y ago
    For the curious https://twitter.com/ID_AA_Carmack/status/792158370186670080 https://twitter.com/ID_AA_Carmack/status/792158370186670080
- thrwaway_gp 10y ago
  1. Be a female "graphics programmer". 2. Get an entry level job or go straight to filling some diversity quota if lucky. (There are quotas for working on government contracts and quite a lot of graphics programming jobs there). 3. Nobody will doubt your ability publicly for fear of being accused of sexism, mysoginy etc. (You seem to be downvoted for the same right here). 4. When/if you get fired - get a more prestigious job, using the previous one as a proof of competence. Goto 3.
  - deleted 10y ago
    [deleted]
pandaman 10y ago
It's bad. One one hand it gives something more or less true in a "casual" manner but on the other it's also intermixed with complete BS. E.g. wtf specular does not depend on view direction? It's called specular for a reason. While I have no problem with people simplifying things for introduction to laymen, I think introducing falsehoods like this will do more harm than good.
- psyc 10y ago
  It's just a typo. They wrote "normal" twice instead of "camera/eye". With that one-word correction, it's Blinn-Phong.
  - pandaman 10y ago
    It could be a typo but how are people who is this supposed to target will know? It's not like somebody who was just given a bizarre explanation for dot product (and Lambert's lighting model along with that) will see through it.
generic_user 10y ago
While its true that you probably do not need to be very good at math to do basic graphics, you do need 'some' math. You need to be able to understand the basic algorithms of the graphics pipeline to use them correctly and experiment. The best source for a detailed and 'gentile' intro is still one of the introduction to computer graphic books. You can sit with a pad of paper and work through some of the formulas on paper until you understand what they do. One of my favorites, because it does not use any particular language and the math derivations are detailed and easy to fallow. Fundamentals of Computer Graphics - Shirley https://www.amazon.com/Fundamentals-Computer-Graphics-Peter-Shirley/dp/1568814690 https://www.amazon.com/Fundamentals-Computer-Graphics-Peter-...
m_fayer 10y ago
As someone who's only used high-level UI stacks (DOM, WPF, Android view system, etc.), I would love to read a great article that's a "Casual Introduction to Low-Level Graphics Programming", these are basics that I've been meaning to add to my quiver for a long time. Unfortunately, this less-than-coherent article is not it.
- santaclaus 10y ago
  This is a really fun way to build your own (raterization based) renderer step-by-step: https://github.com/ssloy/tinyrenderer/wiki https://github.com/ssloy/tinyrenderer/wiki
noobermin 10y ago
>Vectors have more values, 3 is common. Very useful for things like position or color. >If two vectors overlap, the dot product is 1. If they are perpedicular (90 degree angle), the dot product is 0. (Note: just for vectors that only represent a direction and have length 1, you can think about varying vector lengths later) Something is terrible incongruent (pun intended) here. How can three numbers have a length, much less length of one? I think here, the mathematical introduction that a vector is just an arrow is better here. It just so happens you can express the arrow as a set of numbers, which I admit is not obvious at first unless you've taken algebra 2. But the jump from "3 numbers" to length is confusing too. The truth is people conflate vectors with arrays, but if you want to think deeper than anyone who does computer graphics needs to, you don't need coordinates or any group of numbers to express vectors.
- santaclaus 10y ago
  > >If two vectors overlap, the dot product is 1. This is only true for a subset of all vectors (normalized or \sum a_i b_i = 1)... > The truth is people conflate vectors with arrays, but if you want to think deeper than anyone who does computer graphics needs to, you don't need coordinates or any group of numbers to express vectors. I'm a math simpleton myself, but computer graphics people can and do go deeper: https://www.cs.cmu.edu/~kmcrane/Projects/DGPDEC/paper.pdf https://www.cs.cmu.edu/~kmcrane/Projects/DGPDEC/paper.pdf
  - delinka 10y ago
    Apparently these notes are transliterated out of the author's own notes. It is mentioned that this is only for normal vectors, just not conveniently inline: "Note: just for vectors that only represent a direction and have length 1"
- delinka 10y ago
  I'm not seeing any indication of three numbers relating to length. I see a gap in information, not a leap from "3 numbers" to "length." What's missing is the definition of a vector: an item with direction and magnitude/length. Using the distance formula, you can determine the length of the vector. So if your vector is <5,4,3>, plug that and the origin <0,0,0> into the distance formula to get a length of 5 * sqrt(2) (approximately 7.071) Further, you can 'normalize' the vector so that the direction is the same but the magnitude is 1. To normalize, divide each component by the length: http://www.wolframalpha.com/input/?i=%3C5%2F(5sqrt(2))%2C4%2F(5sqrt(2))%2C3%2F(5sqrt(2))%3E http://www.wolframalpha.com/input/?i=%3C5%2F(5sqrt(2))%2C4%2...
elpocko 10y ago
Graphics programming introduction, followed by fashion advice for software developers. Heh.
jlarocco 10y ago
Maybe my expectations are too high, but that's just a collection of random comments loosely related to graphics. It's a terrible introduction, and it doesn't give any concrete information on how to get started. My advice for people interested in graphics would be to jump in and get started with a tutorial on the web and then get a book or two to learn more. My recommendations would be: Introduction To Ray Tracing - It focuses on ray tracing, but many of the topics (vectors, matrices, shading, view transforms, etc.) are applicable regardless of the actual rendering method, and it does a good job explaining all of it. https://www.amazon.com/Introduction-Tracing-Kaufmann-Computer-Graphics-ebook/dp/B003VWBY18/ref=mt_kindle?_encoding=UTF8&me= https://www.amazon.com/Introduction-Tracing-Kaufmann-Compute... Real Time Rendering - This also covers all the math, but focuses on rendering at a higher level and covers more ground. https://www.amazon.com/Real-Time-Rendering-Third-Tomas-Akenine-Moller/dp/1568814240/ref=sr_1_1?ie=UTF8&qid=1477765570&sr=8-1&keywords=real+time+rendering https://www.amazon.com/Real-Time-Rendering-Third-Tomas-Akeni... Finally, Computer Graphics: Principles and Practice - This is a great general reference for more specific topics. It's like Real Time Rendering expanded to cover more topics and going into more depth. Not a beginner reference, but great to have when you need more information on something. https://www.amazon.com/Computer-Graphics-Principles-Practice-3rd/dp/0321399528/ref=dp_ob_title_bk https://www.amazon.com/Computer-Graphics-Principles-Practice...

137 points by deafcalculus 10y ago

posterboy 10y ago

js;dr: the page doesn't render without javascript.

Zecc 10y ago
But think of the important reasons why this page requires JavaScript: - - -
Zecc 10y ago
Looking at the page's source code you can actually see the whole text there. Thrice: inside the `content` attributes of `<meta property="og:description">`, `<meta itemprop="description">`, and `<meta name="twitter:description">`. The `content`attribute of `<meta name="description">` is empty. A missed opportunity.
douche 10y ago
I'm really not a fan of this Medium-ization of programming blogs. I find this much harder to read than something more crude and basic, like, e.g. http://lazyfoo.net/tutorials/SDL/index.php http://lazyfoo.net/tutorials/SDL/index.php - static html, no JS (aside from the obligatory analytics, Adwords, and social widget throw-ins), high-contrast, no-nonsense.
- BoorishBears 10y ago
  Man lazyfoo, that takes me back... I remember extending what I learned in the series of tutorials into a tiny Windows/Android cross platform demo a few years ago to get familiar with NDK
joshkpeterson 10y ago
Can we stop making every thread about this? We get it. You use noscript. COOL.

mrspeaker 10y ago

Excellent introductory post! There's so much to digest when you start playing around with things like OpenGL that you quickly get lost in the details... just memorizing things ("now for some reason I have to type "bindBuffer"). It's hard to build up a mental model for WHY you're doing all the steps. This gives a great bigger picture overview! (though, the next step is still the ocean of nitty-gritty details ;)

melling 10y ago

I've got a list of computer graphics resources on Github: https://github.com/melling/ComputerGraphics/blob/master/README.org https://github.com/melling/ComputerGraphics/blob/master/READ...

nightcracker 10y ago

I disagree with the introduction of the article. Low-level graphics programming is incredibly math intensive, and a solid understanding of trigonometry, linear algebra and discrete math is __required__ to be succesful in it. When I say discrete math, I mean fundamental understanding of how data is represented, and how you can interpret data as you please. E.g. using textures to store depth maps or even sound data, IEEE754 floats, etc. There are many areas of design and 3d graphics that do not involve math, but to claim that low-level graphics programming doesn't involve a lot of math is disingenuous and harmful.

noobermin 10y ago
I think they meant most graphics programmers who don't go deeper than the API know much math, unfortunately. It fits her narrative, say "most graphics programmers don't need math" but then goes to demonstrate how much geometry is relevant to low-level graphics.

aj7 10y ago

Does this person know anything about graphics, or is this some sort of creative writing or reportorial exercise? How can one introduce vectors without the word "direction"? How can one so thoroughly screw up the introduction to illumination?

okatsu 10y ago
Calm down. Stephanie has worked at Oculus and Unity and continues to do contract work in AR/VR while running a two-person company with Rich Geldreich from Valve. I have some problems with the post as well but the author's knowledge of graphics is not at stake here.
psyc 10y ago
When you write an article, and John Carmack responds with a correction, you're probably not actually doing too badly.
- monkeyshelli 10y ago
  For the curious https://twitter.com/ID_AA_Carmack/status/792158370186670080 https://twitter.com/ID_AA_Carmack/status/792158370186670080
thrwaway_gp 10y ago
1. Be a female "graphics programmer". 2. Get an entry level job or go straight to filling some diversity quota if lucky. (There are quotas for working on government contracts and quite a lot of graphics programming jobs there). 3. Nobody will doubt your ability publicly for fear of being accused of sexism, mysoginy etc. (You seem to be downvoted for the same right here). 4. When/if you get fired - get a more prestigious job, using the previous one as a proof of competence. Goto 3.
- deleted 10y ago
  [deleted]

pandaman 10y ago

It's bad. One one hand it gives something more or less true in a "casual" manner but on the other it's also intermixed with complete BS. E.g. wtf specular does not depend on view direction? It's called specular for a reason. While I have no problem with people simplifying things for introduction to laymen, I think introducing falsehoods like this will do more harm than good.

psyc 10y ago
It's just a typo. They wrote "normal" twice instead of "camera/eye". With that one-word correction, it's Blinn-Phong.
- pandaman 10y ago
  It could be a typo but how are people who is this supposed to target will know? It's not like somebody who was just given a bizarre explanation for dot product (and Lambert's lighting model along with that) will see through it.

generic_user 10y ago

While its true that you probably do not need to be very good at math to do basic graphics, you do need 'some' math. You need to be able to understand the basic algorithms of the graphics pipeline to use them correctly and experiment. The best source for a detailed and 'gentile' intro is still one of the introduction to computer graphic books. You can sit with a pad of paper and work through some of the formulas on paper until you understand what they do. One of my favorites, because it does not use any particular language and the math derivations are detailed and easy to fallow. Fundamentals of Computer Graphics - Shirley https://www.amazon.com/Fundamentals-Computer-Graphics-Peter-Shirley/dp/1568814690 https://www.amazon.com/Fundamentals-Computer-Graphics-Peter-...

m_fayer 10y ago

As someone who's only used high-level UI stacks (DOM, WPF, Android view system, etc.), I would love to read a great article that's a "Casual Introduction to Low-Level Graphics Programming", these are basics that I've been meaning to add to my quiver for a long time. Unfortunately, this less-than-coherent article is not it.

santaclaus 10y ago
This is a really fun way to build your own (raterization based) renderer step-by-step: https://github.com/ssloy/tinyrenderer/wiki https://github.com/ssloy/tinyrenderer/wiki

noobermin 10y ago

>Vectors have more values, 3 is common. Very useful for things like position or color. >If two vectors overlap, the dot product is 1. If they are perpedicular (90 degree angle), the dot product is 0. (Note: just for vectors that only represent a direction and have length 1, you can think about varying vector lengths later) Something is terrible incongruent (pun intended) here. How can three numbers have a length, much less length of one? I think here, the mathematical introduction that a vector is just an arrow is better here. It just so happens you can express the arrow as a set of numbers, which I admit is not obvious at first unless you've taken algebra 2. But the jump from "3 numbers" to length is confusing too. The truth is people conflate vectors with arrays, but if you want to think deeper than anyone who does computer graphics needs to, you don't need coordinates or any group of numbers to express vectors.

santaclaus 10y ago
> >If two vectors overlap, the dot product is 1. This is only true for a subset of all vectors (normalized or \sum a_i b_i = 1)... > The truth is people conflate vectors with arrays, but if you want to think deeper than anyone who does computer graphics needs to, you don't need coordinates or any group of numbers to express vectors. I'm a math simpleton myself, but computer graphics people can and do go deeper: https://www.cs.cmu.edu/~kmcrane/Projects/DGPDEC/paper.pdf https://www.cs.cmu.edu/~kmcrane/Projects/DGPDEC/paper.pdf
- delinka 10y ago
  Apparently these notes are transliterated out of the author's own notes. It is mentioned that this is only for normal vectors, just not conveniently inline: "Note: just for vectors that only represent a direction and have length 1"
delinka 10y ago
I'm not seeing any indication of three numbers relating to length. I see a gap in information, not a leap from "3 numbers" to "length." What's missing is the definition of a vector: an item with direction and magnitude/length. Using the distance formula, you can determine the length of the vector. So if your vector is <5,4,3>, plug that and the origin <0,0,0> into the distance formula to get a length of 5 * sqrt(2) (approximately 7.071) Further, you can 'normalize' the vector so that the direction is the same but the magnitude is 1. To normalize, divide each component by the length: http://www.wolframalpha.com/input/?i=%3C5%2F(5sqrt(2))%2C4%2F(5sqrt(2))%2C3%2F(5sqrt(2))%3E http://www.wolframalpha.com/input/?i=%3C5%2F(5sqrt(2))%2C4%2...

elpocko 10y ago

Graphics programming introduction, followed by fashion advice for software developers. Heh.

jlarocco 10y ago

Maybe my expectations are too high, but that's just a collection of random comments loosely related to graphics. It's a terrible introduction, and it doesn't give any concrete information on how to get started. My advice for people interested in graphics would be to jump in and get started with a tutorial on the web and then get a book or two to learn more. My recommendations would be: Introduction To Ray Tracing - It focuses on ray tracing, but many of the topics (vectors, matrices, shading, view transforms, etc.) are applicable regardless of the actual rendering method, and it does a good job explaining all of it. https://www.amazon.com/Introduction-Tracing-Kaufmann-Computer-Graphics-ebook/dp/B003VWBY18/ref=mt_kindle?_encoding=UTF8&me= https://www.amazon.com/Introduction-Tracing-Kaufmann-Compute... Real Time Rendering - This also covers all the math, but focuses on rendering at a higher level and covers more ground. https://www.amazon.com/Real-Time-Rendering-Third-Tomas-Akenine-Moller/dp/1568814240/ref=sr_1_1?ie=UTF8&qid=1477765570&sr=8-1&keywords=real+time+rendering https://www.amazon.com/Real-Time-Rendering-Third-Tomas-Akeni... Finally, Computer Graphics: Principles and Practice - This is a great general reference for more specific topics. It's like Real Time Rendering expanded to cover more topics and going into more depth. Not a beginner reference, but great to have when you need more information on something. https://www.amazon.com/Computer-Graphics-Principles-Practice-3rd/dp/0321399528/ref=dp_ob_title_bk https://www.amazon.com/Computer-Graphics-Principles-Practice...