Make Your Own Raycaster Part 1 

I don't know anything about video games but it is really neat to see how the programming is done. Love your water sponsor 🤣

I can't find the *WATER* link

The dislike is from Unity

Damn dude, this is some quality content

Raycasting seems really complicated. But this video really makes it seem way less scary!

Man, idk if you are going to read this, but really thanks, I was trying to create a raycaster for a very long time and i finally created a functional one with the help of your video

We totally need the 2nd part of this tutorial, It's the best raycasting tutorial I could find, and it would be super cool to have all the features you mentioned, keep up with the great work!

Really makes me want to pick up C and start coding. Please do make a part 2, your explanations are clear and to the point

00:00 Intro 00:17 Games that Use Raycasting 00:48 Prolog 00:57 Sponsor 01:27 Introduction 02:42 Beginning of the Coding - Gray Window 03:14 Coding - Player and Top View 04:01 Coding - Map and Top View 05:14 Coding - Changing player's control to FPS like 06:43 Coding - Casting Single Ray (for horizontal collision/horizontal check) 09:49 Coding - Vertical Line Check (VLC) 11:09 Coding - Combining HLC & VLC to Calculate Ray's Length 12:33 Coding - Casting More Rays 13:43 Coding - Visualizing the Rays in "3D" 15:09 Bonuses

His voice really matches the cat so well

13:46 "And by we, I mean... Umm... Leo." I feel attacked.

Hi 3dsage! I'm a bit confused as to where to find the link to your sponsor.

Not only is this very digestible educational information, it's also hilarious! Thanks for this content.

I've been looking for an explanation on raycasters for years, this is great! Thank you very much, please do a part 2

This was a very excellent video for an introduction to rudimentary 3D graphics for programmers! After 4 hours of refactoring the code in Java using the standard graphics library and digesting the math, I was finally able to do everything in the video! When I finish the other tutorials, practice it, and finish my own game, I'll be sure to tag you and give you all the praise in the world. I can't thank you enough. No video details this early technique in Java on RU-vid, so I'm glad that your code is so easy to transport over to Java!

Can’t wait for the part 2! Also, I can’t understand how such a RU-vid like you still do not have 500000 subscribers, you really deserve more!

Just finished making this in javascript and Html5, had to workaround some issues but it was two (long) days of fun. Thanks for making amazing videos that push people forward!

Interestingly ray-casting is actually pretty darn inefficient, even on a 286 in 1992. John Carmack's foreword for Fabien Sanglard's book mentions this - how a Doom style raster engine would have been more efficient (hence Wolf3D on SNES uses a BSP tree raster engine, rather than ray-casting). For your GBA tutorial if you want to avoid devkitPro I'm actually currently writing a new CMake based toolchain that uses ARM's GNU embedded toolchain - complete with debugging in Visual Studio + mGBA and compatible with any CMake IDE. Might be a lot simpler than asking people to install devkitARM.

ngl i appreciate you not slowing the video down to show the code step by step but rather explained what you were doing right along with it. Makes it so you can work at your own pace if you choose to follow along and i respect that.

part 2 ? when when ? make a full series !

I really appreciate your efforts into explaining coding in a way anyone can understand!

pro tip for anybody following this tutorial: don't just copy the code, attempt to understand why each math thing needs to be there and how it contributes. you actually learn what's happening and you feel a lot smarter by the end

Just wanted to say thank you for making this. I've just used it for a project I'm working on and it helped immensely.

We definetly need a part 2 to this, it was very good!

really engaging tutorial though

I love this series but it would be a little easier to follow the code if the variable names were just a little bit more descriptive. I know short variable names are more convenient but when we end up dealing with a bunch of variables named px, py, ry, rx, mp, my, mx, ra, pa etc. it's a bit tough leaving mental notes what each one was short for.

Amazing tutorial! Simple and entertaining. I’d love to see a part 2!

thanks so much for making this video. i have been trying for an EXTREMELY long time to find out how to get rid of that dang fish eye effect. I was doing all of this the naive way also, so you are really helping me optimize it.

This is very well made! Great job sir!

Nice video. :) Made one back in 1986 on an Amiga 1000, assembly instead of C/C++.

Your channel is amazing. These videos have been my drug for a while now. I LOVE THIS

I don't mean to sound like a heathen but I was actually following this tutorial using Visual Studio and SFML. Your instructions were still clear enough to get a good idea of what to do. Thank you immensely. This is a great tutorial.

This cleared something up for me, so thanks ☺

Now I want to make one myself but maybe in JavaScript or something like that to try how far I could push the idea

Simply Brilliant, Brilliant, Brilliant ! You made it look so easy, interesting, and inspiring.

By far the most educational and awesome video I’ve seen in a while! Thanks for sharing this, excited to try and code this myself! 👨‍💻

Hey I am having lots of trouble with the code crashing when i am at the point that I have to scan for lines. Could you please send me a link to the source so I can check what I am doing wrong

Your name doesn't lie, amazing video! Can't wait for part 2 PS: There is a but... don't like the sponsor, water is such a useless product, i can live perfectly without it...

Awesome video loved the sponsors and the “and by we I mean... “ 😂 keep it up man!

Really well made and was interesting to watch. I'll look forward to the GBA tutorial.

This is a great tutorial. I implemented it along in Java. So a 17 minute video took more than an hour to get through. I had some problems, though. For example, when running before certain parts were implemented I would get errors that you didn't show getting. In particular there was an index out of bounds error for an array, on the line that used map[mp]. You would later in the video add the condition mp>0 to remove that error. I anticipated that. But it might suck for people implementing along to see that much later, rather than earlier. My final product came out pretty good, but it's a little glitchy. Sometimes I have most rays properly coming out of the 60 degree line of sight, but a few rays coming out of the back of the character's head, in the other direction. I don't yet know what accounts for this. Maybe if I copy and paste your Github source code and then convert it to Java, it will correct whatever error there is. Maybe it is a typo, as I made a few of those already. But the previous typos were easy for me to diagnose and fix. This one seems more confusing to me. I also wonder if your part 2 video won't just correct this automatically, if I am loading a texture rather than drawing a line. But I suspect that the error will remain for as long as any rays are being cast backwards. One part that I thought might cause the problem is... You have two ifs, one which checks a less then, and one that checks a greater then. But this ignores the case where the lines are equal. I had originally coded it with an else rather than two ifs, but I changed it to two ifs thinking that might fix the problem, but it didn't. Hmm... Now that I think of it, maybe this could be the cause of the backward ray cast. If the first if sets the ray correctly... No wait, that doesn't make sense. Hmm... Checking your Github source now, you only have 1 if where you had 2 ifs in the video. The two ifs compared disH and disV. But you only have one condition for that in your Github source, and you set one to be the other if it's longer. I wonder if that'll correct my backwards casting rays. Edit: Yep, that fixed the backward casting rays. But I still have rays traveling through walls sometimes. Weird. I bet if I just copied and pasted your Github source and converted it to Java it'll work. Edit: Translating from your Github source fixed the problems.

The only problem with this is that walls can only be in certain places. I made one were the rays just detect with the walls them selfs. (With a loop the find the collision with each wall and finishes on the closest distance) My method is much more efficient for scenes that are big or have walls in any direction. However, for like a big tightly cramped maze, yours would be better. (more walls, less space, straight walls) But I could add in chunking and then there would be almost no situations where mine is worse. My method requires more math, however. How it does it is that it to the ray into a y=mx+b equation with a starting point and each wall into a y=mx+b with two endpoints. Then it performs solving a linear equation of the two to find the intersection point. It makes sure it is valid (correct side of the placer and not above or below the wall). Then finally it calculates the distance to the point. Does this to all the walls then it will find the smallest distance and that is the final distance the ray has traveled. There are also more optimizations that could be done to both yours and I did to mine, in which you only shoot out certain rays in the direction that you need to (this a good description of it ncase.me/sight-and-light/ ). One last thing: whenever I said my method, I do not mean I am the very first to use it or am I trying to talk about how mine is so much better than everything else, it is just that I could not find a better way to say it.

This is awesome! Hope you do a whole series of these.

Gosh a part 2 would be amazing. I've already watched this video at least 20 times and used it to code a ray-casting engine.

hey, im having issues with creating the rays. is there a discord i could join for someone to help me out?

your sponsor “water” convinced me to go down at 3am and drink “water”

Hit us with that second part please! Also, could you highlight the changes you make as you make them? You've really come a far way since your first few tutorials but I find that for some people, who would be total beginners, they could miss some of the quicker changes you make! Keep up the great work man! :)

This was a very interesting video! Looking forward for the GBA tutorial!

wow... you make it sound simple... i feel like i could do it with the minute little programming knowledge i may have with just a bit more effort... and tutorials.

The real new interesting thing invented by ID was the sectors, if I'm not mistaken.

Thanks for making this video! I couldn't find a lot of information about how a raycaster works but your video helped me be able to make my own implementation in python.

That water commercial exactly emulates the style of a modern generic commercial. Got that super out of focus lens flare stock footage blended using soft light. Even snuck in a lens flare transition 🤣 beautiful

Can someone explain a bit more about -1/tan(ra) at 7:02. What does the negative inverse of tangent do exactly and what happens when you multiply (py-ry) by the negative inverse of tangent. Sorry if this is a simple concept I'm just trying to understand a bit more :)

For those using Ubuntu, compile in the terminal like this: g++ original_file_name.cpp -o file_rename -lGL -lGLU -lglut and then just: ./file_rename Luck!

I love games but I know nothing about games engines. This vid was recommended to me by a couple of guys who work in the games industry. I watched this and found it simply fascinating. I was like "That's it? THat's a game engine?" but I was also like "That is so brilliant." Thank you for such a good explanation of how this works.

Excellent job, @3DSage! Your video is informative, straightforward and even fun to watch (thank the cat - Leo, right?). I got really inspired! Thank you for putting this all together and sharing with us.

Love this! I don't fully understand all the math yet :P looks like there is a small mistake around 8:33 with your second typecast on line 70 though. :)

can you please give me a link to the complete source code?, my code isn't working and I want to see if I can fix it.

I sure love your sponsor. I couldn't live without them!

Finally a good raycasting explanation that I can actually follow along. Im using your video for creating a raycasting game on pygame. Thank you!

Download to the GBA raycaster?

Can i get a coupon code for my water?

Your sponsor literally keeps me alive. Thanks sponsor.

I am in the process of writing my own game engine in DirectX and I stumbled upon this video. This is super useful for me! Thank you!

Please do a part 2!!!!!

What the hell where is the promotional code for the water! This is clickbait! Disliked, unsubbed.

I've recreated step by step your Raycaster game and it was really fun to do ! I'm hyped for the next episode :D

this is really cool, thanks 3DSage. Relatively little code and yet such an effect

Interesting, as a high-level programmer, I always thought C was much harder to understand!

Where’d you get the “code.cpp” file at the start? And when I typed it out myself and compiled and ran it opens “glut.h” and says (in the compiler tab at the bottom) “483 c:\program files (x86)\dev-cpp\mingw32\include\GL\glut.h undefined reference to `_glutInitWithExit@12’ “ what does this mean and how do I fix this? I know I’m late but i really want this to work! Thanks in advance! EDIT: I fixed it by adding a ‘#define GLUT_DISABLE_ALTEXIT_HACK’ but now it has a red bar on line 7 (now 8) and an error saying “undefined reference to `_imp_glClear@4’” I’ll try to fix it on my own... I’ll update if I fix it and more errors pop up! Guess this comment is my journal now!

This tutorial is amazing, I wanted to make a 3d game in pygame, i got all the way to ray casting, but 3d rendering seemed so complicated. Then after hearing that its just rectangles, I attempted to make it all, and it worked firat time, and i exploded in happiness. Gonna learn some more soon. Thanks alot for this

Thank you so much for the tutorial it was really helpful. It would have taken me ages to figure this out all by myself, but by using this model as a starting point I can customize it and add extra features, for now I'm adding collisions and some wall designs (don't know how to add textures so I'm writing them with code)

When I compile at 9:19, the ray doesn't show up.

please, name variables properly, this is very bad practice to name variable like pxa, pv, uip etc.

Followed this tutorial to make this in java without a game engine, works very well. Thank you! Will be checking part 2 and will be adding some features of my own as well maybe.

Thanks so much for this video! It inspired to write my own ray casting engine in pygame, and you really made me realize how easy it is to do so!

You really need a coding style dude, the code is almost unreadable :/

your code is unreadable

please make a part 2 that is everything I want in a part 2 video about this stuff. Such a good video I love it.

when i hit the ad i instantly subbed lmao this channel is great

I just found you today and you like my favorite person already. I’ve also never heard someone else who does the S whistle with their teeth and tongue when saying some words. I’ve been messing with OpenGL and Vulcan the past few months and you are awesome

i have a python background, and raycasting has always been interesting to me, but felt like it was too complicated, even though I don't understand a lick of the code, you made the math and concepts way to easy to understand! You are a fool for giving me this power

thx so much for sponsoring this video

Nice work man! I am waiting for part two.

I love that, I can't wait for part two!

Fantastic! This is very straight-forward, I got it all to work in Godot. Except fixing the fish-eye effect, it works vertically, but horizontally it's going insane

hyper-interesting and very well-explained! I subscribed immediately. P.S. I love the cat!

Awesome videos sir! Thanks for sharing this. I've always known the basics behind raycasting, but seeing it from a programmer's point of view is fantastic. Thanks again!

Now this motivates me to listen better at maths classes haha, super interesting video, great job, I really enjoyed it! :)

Ever since it came out, I was curious about how they made this game. I learned C at school at the end of the 90's and still it wasn't clear to me. This video finally tell me the truth, after all those years. Thank!

Hey. Your channel is amazing. Thanks for creating nice content with this great quality!

I dont think I could live if you didn't show me the sponsor. Thanks, singlehandedly saved my life!

Thanks for making this AWESOME tutorial video! I started up with a little bit of UE4 and Python knowledge but after watching this with visual studio open for 6 hours, I think I get it and even implemented fun stuffs like coloured blocks (as shown in the video) and jumping. This friendly and interesting tutorial even pushed me to start studying C/C++! Hope to see more good stuffs like this one in the future.

Thanks for the excellent explanation! I made a raycaster 30 years ago as a sample project to teach myself x86 assembly. The one part that I never got around to fixing was the fish eye effect. Turns out it's just a projection onto a plane perpendicular to the view vector, but I didn't know that at the time.

Subscribed! Like your content! Waiting for next part

Please make more and more video like this!!!!!!!! Really appreciate how you break down very complex things for us

Damn, animations on point my man. Keep it up.

This was the first advertisement I enjoyed more than LucidChart. Well done, sir.

I Would love to see a part two. BTW Great video

Amazing video. Gave me the will to try new stuff. Part 2 is needed, hope you're working on it.