Ray casting fully explained. Pseudo 3D game

➤ Description
In this video I am explaining ray-casting.
Ray-casting is the method which was used to render pseudo 3d games before. Wolfenstein 3D uses ray-casting.
➤ Music
• New Day - Patric Patrikios
• The Joint is Jumpin - Joel Cummins
➤ Project
• github.com/ric...
➤ About
Hello! And welcome! My name is Eric and I'm 15. Learning and explaining new things fascinates me.
➤ Credits
Without Grant Sanderson AKA 3Blue1Brown it wouldn't be possible to make this video. I used his open-source project called manim to do all the animations.
/ @3blue1brown

[@harding5674]

i dont understand how this video is only at 917 views (as in, i dont understand why it doesnt have way more views) like this is an extremely good video

[@weirddevers9165]

Thanks🙂

[@gabrielsegura626]

I don't undestand this video

[@ilikemorestuff]

Congratulations! You give a concise explanation of the math, why and how it's used in this context, and also provide details on how to employ the given formulae for fine tuning the output. Well done!

[@Squeph]

For wall colour, you can change the colour the lines are drawn depending on the distance to the wall that you calculated, so it gets darker the further away the walls are

[@dhanushc5744]

this was so confusing. feel like lot of information is omitted and not explained in details. im not sure how it is "fully explained". Not even sure if the issue he just assumes others know or he incorrectly explained.

[@ismyname_jep1394]

Wow thank you for simplifying this! I couldn't find any other video that does not gloss over of why and how ray casting works.

[@weirddevers9165]

oh gosh! It’s been more than a year since I uploaded it. I’m so glad it helped you

[@ahmadshariq7116]

This is the most comprehensive and simple explanation that I have seen to date. Great job.

[@giovannicesaramorim9adigan961]

How do you know when you have hit a wall? I'm thinking about using a matrix, but wouldn't that just be infinitely small points in the determinate coordinates? The numbers in the matrix aren't lines

[@eddie.z]

Geat TUtorial. In-depth and Organized.

[@weirddevers9165]

Thank you

[@eddie.z]

@@weirddevers9165 No problem

[@blow42176]

Thanks for this great video !

[@excortia453]

hello, i have a question. when u calculate xs, shouldn't xs = ys/-tan(angle)? also, shouldn't i check if player is facing upwards or downwards, becouse when it faces upwards yn = Player.y/cellsize * cellsie and when it faces downwords yn =Player.y/cellsize * cellsize + cellsize

[@YiTsukENyt]

Really good video

[@Malenki_Stefan]

I love this video

[@thanhdangthingoc9301]

For any one who wonder the math formula for horizontal was correct he just forget to round up like 2.8 to 2

[@wdpko2926]

why do u divide cellsize and multiply it again at 2:00 am i just stupid?

[@dannaki_d]

No, you think right way. This formula is 0 return.

[@khangdao8119]

Why is yn = (py-(py/cellsize))*cellsize in 2:08 ? Is there any trigonometric formulas there?

[@ringzero3260]

that part does not make sense. probably a mistake. (py-(py/cellsize))*cellsize will always equal 0

[@hakansuner2578]

It uses the formula (cellsize-(player.x/cellsize)*cellsize) for the same calculation when checking vertical intersections. It makes sense when the same formula is used for the y position. I think there was a little confusion

[@unmandarinoalgiorno...9321]

@@ringzero3260 it's because in programming, the result of py/cellsize will be an integer. For example 5/3 will be 1. But i think the formula to count xn when checking vertical intersections is probably wrong. From what i understand, it shoud be xn = cellsize - player.x + (player.x / cellsize) * cellsize

[@YiTsukENyt]

Ity deserves 1 million views

[@YiTsukENyt]

at least

[@breakdancerQ]

1 billion at least

[@ringzero3260]

@@breakdancerQ it's full of mistakes.

[@moohot3479]

I love your video; however, I still have a few questions. For the Horizontal intersect at 2:00; the Y nearest has the Player.y over cell size then multiplied by cell size witch would cancel each other out then by subtracting Y nearest, would output a zero no mater what the two variables equal. Did you mean to put (Player.y (Player.y/cellsize)) cellsize instead of Player.y (Player.y/cellsize) cellsize? I also noted at 2:32 you used cell to subtract, divide and multiply when the previous step only used step to divide and multiply; y-(y/s)s and s-(x/s)s (used letters for simplification) . It was a great video and helped me out tones, I'm just a little lost at a few parts.

[@weirddevers9165]

player.y/cellsize should be evenly divided. For instance if player.y is equal to 131 and cellsize is 64 then player.y over cellsize equals 2. In this case the equation gives the following result yn = 131 - 2*64. If you still have questions I’m willing to answer

[@moohot3479]

@@weirddevers9165 I didn't get the divide evenly part. Thanks for the help, you make things easy to understand. I'm looking foreword to your next video!

[@johnvine5731]

Ah, divide evenly means cast the floating point result of the division to an integer value. (int)(player.y/cellsize) Took a while to realise that! player.y-(( (int)(player.y/cellsize)*cellsize)

[@clock0789]

Thank you sir!

[@joaquimjesus6134]

MapResolution = 32 'cellsize PlayerPosX = MapResolution + 20 PlayerPosY = MapResolution + 20 PlayerAngle = 0.1 'Radians NearstY =PlayerPosY- PlayerPosY / MapResolution * MapResolution why i get zero?

[@dannaki_d]

Because the formula is incorrect in the video.

[@SbAlmagro]

2:40 How come tan a = y_s / x_s -> y_s = x_s / tan a? Could you explain?

[@Cloud-kd7mx]

tan a = y_s / x_s 1 / tan a = x_s / y_s y_s / tan a = x_s y_s = x_s / tan a

[@SbAlmagro]

@@Cloud-kd7mx Thanks. Could you explain how come y_s / tan a = x_s -> y_s = x_s / tan a?

[@Cloud-kd7mx]

@@SbAlmagro this equation is incorrect Because if y_s / tan a = x_s Then y_s = x_s * tan a

[@SbAlmagro]

@@Cloud-kd7mx true. But that is what you wrote.

[@Cloud-kd7mx]

@@SbAlmagro oh, then it's my bad, lol, didn't read myself

[@alisson4387]

I can't understand "-" in xn = cellsize - (player.x / cellsize) * cellsize, timing 2:39. I was expecting xn = cellsize + (player.x / cellsize) * cellsize. (player.x / cellsize) - tell us how much cells the player walked throng x axes. (player.x / cellsize) * cellsize - we convert cells walked for pixels walked. this value corresponds the left side in the cell where player is currently. cellsize + (player.x / cellsize) * cellsize - give us the right side of the cell where player is currently, in others words, the y value where first vertical intersection occur.

[@Haunted.01]

at 2:00 yn = Player.y - (Player.y/cellsize)xcellsize is 0 right?

[@Haunted.01]

oh he is using integers, ignoring floats.