Vertex Buffers and Drawing a Triangle in OpenGL

[@rapidreaders7741]

Me anxiously keeping my eyes peeled for the cactus on his table, hoping he doesn't accidentally stab himself, only to nearly get a heart attack at 5:30

[@carlosdalomba]

LOL

[@ibrahimhabibeh6904]

Wow I see Cherno still looking at our comments 3 years after posting ❤️

[@widrolo]

@@ibrahimhabibeh6904 oh my god i didnt even notice that

[@StarContract]

Top quality channel. The best around for cpp.

[@raf.nogueira]

OMG, I tried to learn modern OpenGL for so many months, and only now I finally understand the basic pipeline, Thank you so much Cherno!

[@RomanWaves]

i dont get anything actually ...so there buffers who interpret a stream of bytes ? is there any other course, which kind of starts a bit earlier ? i mean, i understand on a very basic level what happens with graphics ... but cherno lays out the code as if it is a logical progression, whereas i cant follow - anyone on the same page ?

[@thousandpoundcat5696]

@@RomanWaves check out his C++ series, maybe look at the Arrays video, or even earlier if you want to learn about bytes and memory. in this case, the memory space (buffer) will be allocated in the GPU (as it is good at graphics), which can be accessed using OpenGL+GLEW

[@brod515]

I've Used Photoshop and that analogy of how binding compares to Photoshop layers is Brilliant.

[@zorbix3652]

hi

[@brod515]

@@zorbix3652 hi

[@vectork3]

@@brod515 ayy you replied after 2 years. How are you with opengl and graphics?

[@zelda_smile]

@@vectork3 its been 2 weeks, we need to know

[@alfonsld7684]

Come on man, tell us!

[@chrisreuter5843]

Man you're an awesome teacher. I found your channel about 3 days ago, and it's already in my top 5 favorite KZbin channels ^^b Thanks so much for putting in your precious time and effort in teaching us! XD

[@slap_my_hand]

5:50 I never knew that you can select text like that in visual studio

[@alexkiecker4175]

Shift + Alt + Arrow keys do the same thing.

[@borekworek69]

@@alexkiecker4175 or alt + mouse click

[@feschber]

@@borekworek69 it also isn't just visual studio it works almost anywhere

[@VivekYadav-ds8oz]

Can someone please tell how does Cherno does that thing where he selects a certain code then just uses some keyboard combination to shift the whole block of code up or down. This feels very useful when you want to put some code outside a scope INTO the scope.

[@osere6432]

@@VivekYadav-ds8oz alt + up/down with the line selected or cursor on the line

[@p9malino267]

I've been having difficulty with looking for decent tutorials for opengl but then you came along and made learning opengl for me so much easier! Your tutorials explain things so well and are great for beginners. Thank you for making them!

[@amiright7784]

I shall ask my uni for a refund and become the ultimate patreon.

[@zorbix3652]

good 4 u

[@felixchien1664]

right you are my good sir

[@rukna3775]

but uni gives u a degree, youtube doesnt. no offense, I am also a supporter of fuck school and learn online cult but still, in real world interactions between people, having a degree makes ur daily interactions a lot easier.

[@KayVerbruggen]

Damn, I did not expect you to upload this consistent. If you can keep this up, you might be the first youtuber I'm gonna donate some money to!

[@AllanJeremy]

agreed, he's awesome

[@alexkiecker4175]

Is he going to pop your donation cherry?

[@mhammedhassnouni4755]

Ce jeune est un génie !!

[@OGA-b4l]

did you donate?

[@SamWillBenchYa]

@@mhammedhassnouni4755 lol

[@robosatchlol1099]

I just found your channel and must say amazing job and thank you so much! I'm currently preparing for an entry exam for a game engineering degree and your videos are helping big time! You earned yourself a new subscriber :)

[@JasonEwton]

Dude. You're easily the best resource for modern OpenGL and im only on episode 4. Mad mad mad respect for what you're doing. Can't wait for the game engine bit (polite request to make it 3D)

[@sarahshahzad]

I love these series so much! I started programming in 2013 and OpenGL was alien to me when I started in 2014. This is the first time I actually understand stuff without searching for everything on 10 other tabs. Thank you! (That charisma though)

[@clodgozon3968]

Back then, I wasn't able to follow your tutorials since my head wasn't "organized" at that time, and I have too poor logical thinking skill to understand you. Now that I do have decent skills, it looks like your tutorials are pretty easy to follow. Thanks Cherno!

[@ewanarends5512]

I've been searching for good openGL tutorials for months, although i use a java binding, this really helps me out, thanks for creating those amazing tutorials! keep it up

[@f41nT]

So basically opengl is working just like the cpu: working with the current value of the accumulator. I'm in my first semester in computer science and at the same time I'm learning open gl with your videos and it's really fun. You explain it so well I understand literally everything and English is not even my first language :D

[@nickgennady]

Wow I know this video is old but it’s so helpful. That documentation site helps me so much. I’m targeting OpenGL 3.3 and OpenGL ES 2 . Now I can check what I’m using is supposed.

[@samdavepollard]

really appreciate the detail you go into; so many opengl tutorials out there which throw a bunch of code at you with superficial explanation many thanks

[@jpsilver3510]

DUUUDEEE!!! I F*ckin love your tutorials!!! Where have you been all my life xD

[@thenerdyouknowabout]

Dear god this is perfect. Youre absolute credit to the community.

[@Fernando-du5uj]

That notion about opengl being state machine was great. It makes so much sense now. Thanks a lot, mate.

[@marcovalentinoalvarado3290]

This channel is dramatically underrated.

[@CriticalFlinch]

Wow your explanation of vertex buffers and their relationship with drawing was great, been trying to understand how it call comes together for a few says

[@MieysoFelix]

For a moment, let's appreciate the work that Yan put in that series. FOR US!

[@rahulta2000]

Awesome video. Learned a ton of stuff from this that even many paid tutorials don't explain well.

[@suhassreenivas1878]

great quality content... and man ... those explanations are golden (from prev video : I finally understood where the openlgl implementation is and what graphics drivers contain) !

[@sajibsrs]

I like your extended version of explanations. Thank you

[@yojalin1877]

Thank you so much Cherno！I come from China,and I am your fans.

[@Marnie_C]

That analogy to photoshop helped explain the binding concept leagues better than my college teacher ever could

[@deblish]

10:11 alt+shift trick was mind blown

[@cameroncollins4341]

same here

[@CipriValdezate]

You are an excellent teacher, far far better than the professors of my uni.

[@samarthtandale9121]

Great video ! Gave a lot of conceptual clarity !

[@prezadent1]

The following 2 lines placed after the line with glBufferData will use the default shader on most Nvidia and maybe most AMD GPUs. You should get a white triangle on black background. glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 2, 0); glEnableVertexAttribArray(0);

[@ErneTalu]

Ty

[@yuansizhu6271]

My teammate tried to teach me OpenGL, but what he said is a mess... So I come watching your vedios and this is brilliant!

[@Argletrough]

docs.gl is mostly the official documentation with a search function, although the version availability indication could be handy... Linux users will be pleased to hear that OpenGL-Refpages (the source for both) exports to manpages, installed in the 3G section. (The package is opengl-man-pages on Arch).

[@ninadsachania3652]

You deserve way more subs, man! Consistent and quality uploads.

[@alexkiecker4175]

"Consistent". Tell that to all the sparky engine fans

[@lCanShowYouTheWorld]

If you get "Exception thrown at 0x00000000 in Engine.exe: 0xC0000005: Access violation executing location 0x00000000. " Try to put your "glewInit();" after "glfwMakeContextCurrent(window);"

[@Temeliak]

Thanks!

[@maddoo23]

Wow, thanks. It solved my other problem. When I ran the code at 17:16, it gave me the error "exited with code -1073741819.". Can you please tell me why it works that way?

[@postulysses]

Ευχαριστούμε!

[@elnazzamani5110]

You explain neatly. I like how you specify details. I wish I found you last semester which I failed Computer Graphics

[@skaffen]

Your series are incredibly useful to understand OpenGL. OpenGL is a weird way of conceiving 3D when you go from scratch 3d engine like me.

[@guineapigmart882]

I must say that the outro is the same top notch quality as the video it self.

[@Ocmersh]

Made a lot more sense coming from you, than my graphics professor. Thanks!

[@RudolfCickoMusic]

Congratulations for that very educational and clear videos. I learn very much with you. Thank you !!

[@Brick10Man]

Your videos are great! Very clear explanations of core ideas in OpenGL. Very helpful.

[@tanchienhao]

BIG fan of this series btw :) thank you so much for making these free for everyone as a fantastic educational resource! at 10:43 cherno said he is not a fan of doing sizeof(positions). why? what's the best practice for the size parameter?

[@chastitywhiterose]

Imagine that the array was allocated on the heap instead of the stack, then you would be required to do it the way Cherno does it.

[@chastitywhiterose]

Or the array was allocated to be a very large array and you didn’t want to send megabytes worth of data to the gpu when you only needed 6 floats to draw the triangle.

[@tanchienhao]

@@chastitywhiterose I see! Thanks!!

[@Lordp00m]

Excellent tutorial! Learned a ton of new stuff already!

[@_Mrunalwankhede]

I didn't understand any code he did or copied in the previous two videos, but I trusted the process, and I think now I will finally learn what the code is actually doing

[@JaccovanSchaik]

OK, two questions: 1. How many buffers would a program typically allocate? Dozens, thousands, millions? 2. You still haven't told GL you're giving it floats, or that there are two coordinates per vertex. Is this still to come? Loving the series!

[@JaccovanSchaik]

No., that's very helpful, thank you. So the limit is the total amount of memory used, rather than the number of buffers?

[@jamesmnguyen]

Jacco van Schaik Yes, very rarely do you reach the numerical limit of vertex buffers.

[@JNelson_]

You explain things so well. :)

[@tomkohler1609]

7:05 You should never communicate to OpenGL with data types like "unsigned int", but always use GL's own types like GLuint. Because GLuint ist guaranteed to be 32 bits, while "unsigned int" may be 32 or 64 bit (depending on the platform and architecture). While this is not big problem when passing values, it could make trouble when passing pointers or upload vertex data.

[@il2626]

why is it guaranteed? if I look at the definition it just defines it as unsigned int

[@tomkohler1609]

@@il2626 Yes, this is true for x86 (32 bit and 64 bit) Windows and Linux, but for another architecture and platform an unsigned int may be 16 bit or 64 bit. This is also stated in the OpenGL specification: „GL data types. GL types are not C types. Thus, for example, GL type int is referred to as GLint outside this document, and is not necessarily equivalent to the C type int. An implementation must use exactly the number of bits indicated in the table to represent a GL type.“ Besides of that it makes the code also more verbose: "What is this buffer thing? Ahh, it's a variable that stores an API dependant value."

[@il2626]

@@tomkohler1609 thanks for explaining

[@MS-bl9ch]

The way you explain right from scratch simply awesome 😎 man 👍

[@zen-ph8yj]

Your series help me a lot thanks.

[@Moriadin]

Superb videos! Thank you!

[@achraf8694]

5:53 how do you select all those arguments perfectly without selecting the stuff around it i can't figure it out

[@achraf8694]

nevermind guys i found it you can click and alt drag or do shift alt and use your arrow keys to move it

[@jasonwhitworth117]

Wow dude. This is the best explanation I've ever heard!

[@rutexgreat3619]

Very professional and simple...

[@austinkim9402]

That Photoshop analogy was a godsend

[@АндрейБорисов-и4о]

Thank The Cherno! Cool video!

[@Killerkraft975]

Currently behind in my graphics module at university and trying to understand what the example code is and this is a life changer 😂 thank you

[@Killerkraft975]

Its funny, a year later, im back here, writing a report on a fluid simulation using this series as a base and needing to refresh my mind on how this works.

[@joepeters8746]

to "drawr" a triangle, I love the Aussie accent :D

[@wyntermc2126]

Excellent videos, really helpful.

[@tomneijman4212]

Around 7:13 Yan is creating an unsigned int buffer, the type of the second parameter of glGenBuffers is GLuint. Isn't it safer to declare buffer as GLuint? I saw that GLuint is just a typedef declaration for unsigned int, so maybe it doesn't matter??

[@tomkohler1609]

Yes, always use OpenGL's data types.

[@certifiedcat6435]

@@tomkohler1609 what about if your working with multiple api and you have to pass around data

[@mhammedhassnouni4755]

Vos vidéos sont juste parfaites, du beau travail.

[@JohnSmith-bs5mg]

Yay! Thanks a lot! I hope that drawing complex polygons will come before shaders. Cause almost everybody do such tutorials: draw a triangle and describe whole graphics rendering pipeline with that freaking triangle. Vertex shaders, rasterization, fragment shaders, etc - and still triangles.

[@kieranvs]

You do everything with triangles! More complex polygons are actually just several triangles next to each other. I'm not sure if your comment was a joke haha, if so I apologise

[@JohnSmith-bs5mg]

Not joking. I don't remember correctly, but there is function that does groups of vertices, which do not have repeated vertices. Like (1,0),(0,1),(0,0),(1,0),(0,1),(1,1) is the default array that describes square of two triangles. But you pack them like (0,0),(0,1),(1,0),(1,1) in the array using that function. I really what to see how Cherno would apply shaders, textures and stuff to something more complex than square, maybe a hexagon? Something that can be used in real 3D model. Drawing complex figures is hard.

[@vaualbus]

You have to have a shader anyways. And complex geometry can be done in geometry shaders. We need matrix and shaders than you can draw complex stuff.

[@kieranvs]

I think you're talking about a triangle strip. That's just a way to push loads of triangles to the gpu without the repeated vertices. The gpu can only draw triangles. It's triangles all the way down, haha. If you want a hexagon, you can draw that using 4 triangles. Any n-polygon can be drawn using n-2 triangles

[@RandomGuyyy]

That's the thing about modern OpenGL. Everything is based on programmable shaders and there are a whole load of function calls just to do a "Hello, World".

[@D1mas21]

Another nice one! Thank you)

[@sahsaaryutin]

This is the best explanation that ever find Even though my native language is Russian, there are no subtitles and specific words are used here Learning OpenGL not rocketscience with You! 👩‍🚀

[@ShirChoi]

why do I get a segmentation fault on glGenBuffers(1, &buffer)?

[@antiHUMANDesigns]

This is where doing it OOP makes things less messy, and less error-prone. For example, quick and dirty to show the point: class Object2D { public: Object2D() { glGenBuffers(1, &mBufferID); } ~Object2D() { glDeleteBuffers(1, &mBufferID); } void Draw() { glBindBuffer(GL_ARRAY_BUFFER, mBufferID); glDrawArrays(GL_TRIANGLES, 0, 3); } void setVertices(float* vertexArray, int numVerts); // or something, calls glBufferData to upload verts. protected: GLuint mBufferID; }; ...and then you'd just... Object2D triangle; // generates a buffer, and will delete it when this object goes out of scope. triangle.setVertices(myVertexArray, 3); // uploads using glBufferData triangle.draw(); // binds the buffer and draws the vertex array. ... and this way you won't forget to bind buffers and such stuff, so you avoid bugs. Yes, obviously not well written, but the point is demonstrated.

[@necrondow_]

As he has said several times... You can choose to abstract the code as you see fit :) This series merely focuses on the OpenGL code required to make things happen. He works for EA, programming the Frostbite engine... So he is certainly fully aware of OOP principles.

[@TechnologyRules]

That's why will never be a good idea to do games using pure JS. Any language without types should not be used at all for anything that involves complex logic.

[@codialex4624]

I am getting an error "Exception thrown at 0x00000000 in OpenGl.exe: 0xC0000005: Access violation executing location 0x00000000." at line "glGenBuffers(1, &buffer);"

[@finnf2462]

finally a normal tutprial that does not speedrun opengl and explains everthing in a logic way

[@amankharb2401]

Keep up the good work man!!

[@cnsujeer]

freaking amazing content and explanation!

[@jessefinnegan1719]

Has The Cherno ever said what theme that he uses? I really like the look of it and would love to use it in VS. Great videos btw.

[@fraelitecagnin7628]

17:16 wow, I'm at a good point then🤣

[@operu]

Is all of this still up to date for 2020? I'm about to watch all this and dig deep, but i wont if its not updated

[@Quesbe]

It is! And it will still be as long as you are using OpenGL 4 (which is still the latest version)

[@operu]

@@Quesbe Is OpenGL 4 the version being taught in this series?

[@IkeVoodoo]

@@operu Yes. OpenGL 4 Is what i believe is taught in this series.

[@DE012471]

I can't learn for my test if the cherno has an opengl series I need to watch.

[@michaplucinski142]

I have worked with SFML a bit and now tried this, because I couldn't find good source to understand vertexes, their buffers and all of that This series makes it easier, but it also feels so complicated at moments, that I am gonna get a headache from that

[@newsogn5148]

Being able to look over your shoulder for the price of a free subscription is a marvel of our society. If I wasn't so distracted half the time I could be so much smarter!

[@ccdd3104]

good video thanks Cherno

[@sundayscrafter1779]

Hi there, does it also work in SharpGL since it’s supposed to be an OpenGL equivalent in C#?

[@jixs4v]

just put in some more effort and use c++

[@oilolive4212]

I am from Mexico, I follow your videos but this video is the only case in which you do not have subtitles, I would greatly appreciate if you could add them Excellent video Good day

[@tricky778]

do legacy opengl functions build buffers and uniforms that we can use in our shaders so someone can paste some legacy opengl that already does some of the right thing and we can just move on with useful functionality done and finished?

[@wesleyferreira3350]

You rock dude!

[@salmanahmad1]

This guy is just magic

[@WilliamAncich]

10:37 Could anyone speculate as to why specifying size with 6 * sizeof(float) was preferable to sizeof(postitions)?

[@1280charms]

the 6 in 6 * sizeof(float) is the sizeof(positions)

[@WilliamAncich]

​@@1280charms But sizeof() returns the size in bytes, so sizeof(positions) returns 24 as does 6 * sizeof(float). My question was why is the second form preferable when the first seems simpler. Watching this back though he says the first method only works because it's allocated on the stack so my guess is it's in the interest of consistency.

[@tristunalekzander5608]

For some reason everytime I open this project visual studio changes something and the last time I opened it glew worked and now it doesn't I get this warning "1>glew32s.lib(glew.obj) : warning LNK4099: PDB 'vc120.pdb' was not found with 'glew32s.lib(glew.obj)'" And I have "glew32s.lib" in my additional dependencies in linker.

[@nanoic2964]

At 8:49 when binding the buffer I am getting a access violation. I am using VS2022.

[@azula8678]

same, how u figured it out?

[@garbohydrates193]

Why didn't you create a swapchain for the front and back buffers?

[@diato2993]

thank you very much !!

[@Albert-px4jo]

If the tessellation shader and compute shader can also be covered, that will be nice

[@shivanshuraj7175]

So good video !!

[@JakobRobert00]

You can also just pass an array directly to the glVertexAttribPointer function. Is there a significant performance boost in using VBOs over normal arrays?

[@alexjulius69]

I'm finally beginning to understand everything, it's been long 3 days let me tell you that.

[@glenneric1]

Great stuff!

[@hichamwarryor3547]

Thanks so much 🌹 I hope some one make tutorials for development Android with c++ 😍

[@joseplano4789]

GREAT channel!! ...It would be nice if you do a serie of integrating assimp library for models and specially with animation, blending between animation, how to load differents animation for 1 modelt etc...

[@davidboygenius6843]

Do I need to know everything about C++ before jumping into Opengl? I understand the fundaments(pointers, references, functions, arrays, classes, structs, conditional statements, loop statements and data types)

[@anuragparcha4483]

Thanks for this series, loving it so far. I had a doubt, why didn't you initialize "positions" array as a standard array type? As far as I have gathered it has no overhead but provides extra functions. Am I wrong?

[@alexhartung2369]

seriously inspiring to enter the field of computer graphics

[@dohyun0047]

i have a question... so glGenBuffer(1, &buffer) is just giving unique id (which is buffer's value, not specified on this video) right?

[@adulpankaj2729]

Good Video. Very informative