Adding ray tracing (back) to my game engine [Voxel Devlog #17]
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- Опубликовано: 6 июн 2024
- Online demo: github.com/DouglasDwyer/octo-...
Additional voxel models: drive.google.com/drive/folder...
It's time for another devlog, and the engine has undergone a ground-up rewrite! In this video, I showcase the new ray marched graphics. I discuss the drawbacks of rasterization and the importance of two attributes in voxel engines: per-voxel colors and per-voxel normals. Then, I explain the performance improvements in this iteration of the engine over my initial attempts two years ago.
Music used in the video:
Karl Casey @ White Bat Audio - The Saga
Chris Doerksen - Chase
Karl Casey @ White Bat Audio - End Credits 
Игры
![Doubling the speed of my game's graphics [Voxel Devlog #18]](http://i.ytimg.com/vi/P2bGF6GPmfc/mqdefault.jpg)
![Doubling the speed of my game's graphics [Voxel Devlog #18]](/img/tr.png)
![Natti Natasha - Quiéreme Menos [Official Video]](http://i.ytimg.com/vi/R57RrTjRGxk/mqdefault.jpg)
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Great video, please try using frame interpolation based on ground-truth motion maps generated by GPU and then apply this map to previous frame multiple times
Bro I made that tetrahexaconta tree joke before 😢 no credit 😂 joke aside, you are wrong about rasterisation vs marching, use a GBuffer to resolve the lighting, independent of the rendering type. Also light probe might help as a light cache, which would open gather as scatter global illumination. Look at hddgi too, you basically have the structure to do it by default. You can also have nlogn ray update with hierarchical segment tracing cache in hierarchical lightprobe.
bro why dont u make voxels that represent vertices instead of cubes? u will have less faces for a smoother look. but u might need to instead of doing culling u need to decide the shape of the voxel based on its neighbours, so depending on the situation if it cant be a vertex it will be like a lowpoly sphere if theres no neighbours, or something like this ynow?
edit: this is exactly my plan for my game called pretend, but rn im working on more basic projects on irrlicht to get used to it and then progress using only irrlicht (since its faster and more compatible than godot)
I had a dream. That every one of the "I made a voxel engine" youtubers came together to code an open-source voxel engine and put it on github under an open-source license, and it was so awesome and slick and efficient that the open-source community came together and rebuilt minecraft and hundreds of other games/mods on top of it.
Then I woke up and I had to go to work :(
Great video.
Sometimes I do wish that I could team up with another voxel RUclipsr or two. We would be able to accomplish more, faster, than by working on our own.
The Smoothieboard guy?? This is not a crossover I was expecting lol :)
@@NerferCoAHAHA First time in 10 years I'm "recognized in public" :) I'm famous \o/
Did you use the board? We're working hard on v2, we'll be done shipping the kickstarter boards soon, I promise !
@@DouglasDwyerMaybe ask? In my experience, that works much more often than people expect.
Given how they influence each other, by taking inspiration, that's working together in my book... Also I literally invented as a joke the word tetracontahexaconta for 1bit voxel, and guess who took large inspiration from it because I commented it? 😂 I know the literature on the subject, nobody else use that word, well now it's enshrined in his engine 😂
Not only have you gotten better on the technical side of things, but you have also improved a lot in video quality! Keep going man, love your stuff!
I wanted to make a comment like this but you already stole the show.
ok@@prltqdf9
The data structure you're describing is called an N^3-tree which generalize octrees. Since you use a branching factor of 4, that would be a 4^3 tree. As you noted, it's possible to efficiently traverse this structure thanks to the bitmask trick. A very efficient algorithm for traversal is called hierarchical DDA (digital differential analyser), which is more commonly used for dense voxel grids but can also be applied in a hierarchical fashion on each level. Note that you may use a different branching factor on each level in order to reduce the depth of the structure while still retaining good sparsity. There is a paper describing all of this called "VDB: High-Resolution Sparse Volumes with Dynamic Topology" in case you need a reference. In my own work, I use a 3 level hierarchy where the first level is dense and the following two use a branching factor of 4. Hope this helps :)
8^3 using avx has to be faster tho right?
@@solenskinerable avx is a set of vectorized floating-point arthmetic instructions on the cpu, right? This video and my comment were considering a gpu implementation.
Now, in the case of cpu ray tracing, I suppose you could use vectorized instructions to trace multiple rays in parallel but this doesn't have anything to do with the datastructure. Ray tracing along a single ray remains a sequential operation that cannot be parallelized.
This small niche of voxel engine ytubers is so comfy
We've become a remarkable little community, haven't we? :)
Welcome back to raytracing! I’m really excited to see where you take this engine.
Thanks frozein! It seems like all of our engines are headed in that direction, huh?
@@DouglasDwyer Yeah there's been some amazing progress from everyone lately!
THC Tree 😅. I've heard it referred to before as a 64-tree
what about kd quaternary tree?
@@punchster289what about CBD tree?
@@cvabds yes i like that one
THC Tree is definitely sticking for me 🤣
DUDE! 10:49 This reminds me of the old "Ace of Spades" game. Basically a voxel fps that could run on anything when I was a kid.
I would love a sandbox game or anything really in a retro style like this!
Keep going I got really excited while watching this video :D
That game was so good.
fun fact! to this day it is still playable and quite enjoyable.
The 2 most used client implementations are OpenSpades and BetterSpades, the server list can be found on the build&shoot website
I was so sad when it died
The low-res style is sick! I think it would suit a horror game very well.
It's got an interesting charm to it, like an old retro game except 3D and using voxels
Lower resolution looks perfectly fine. imo it will create better result if used well
I mean, if you're a programmer in your early 20s and you like CG programming - then you need to make your own voxel engine. I don't make the rules.
Holy crap that church looked amazing
baked voxel lighting looks awesome - you can see it in Ethan Gore's demo too
@@goobus_floobus yea I follow him as well 😂
@@TheDroidsb Every time I see the scale of the world in his demo my brain explodes 😂
GPU memory isn't slow, it's way way faster than standard system memory. GPUs aren't designed though to be programmed like CPUs you need to take into account the architectural differences and leverage the GPUs huge advantages when designing memory structures to be run on them.
This so much.
Amazing progress, I love your devlogs! :)
Thanks for watching, Xima! Your engine is very inspiring. I'm excited to see where we can take web-based voxel graphics now that WebGPU is maturing.
Awesome! It's incredible that you had the motivation to re-write all of that.
Lets go!
Nice to see the project coming along! Very excited! Thank you!
Well DonE! I absolutely love the new vid style! Please keep up your good work!
Loved the video! also thanks for linking Gabe's channel that one's new to me
great progress, I've been a fan of voxel worlds since I was a wee little child, so it's always a treat seeing some new progress in this arena
Also known as a multi-layer grid, I have used these a lot. You can actually make it a little more efficient memory wise for spatially by hashing multiple values in the same nodes. The first low resolution grid is sometimes also called a bloom filter. You can use a processor's vector instructions like SIMD, openvc or cuda to skip many empty bits at once.
Really beautiful! And the performance is insane 😲
Easily my favourite RUclipsr, another great upload!
Super awesome! It is pretty funny how many dev log videos start with. “I decided to reprogram it from scratch” 😂 I am also guilty of doing this tho so can’t say much
First time I've come across your channel. I've always felt voxels are like a computer making graphics like (checks notes) a Post-Impressionist oil painter. The church and village at the end of the vid? Both facinate and excite my brain for reasons I simply can't fathom. Love, love, love voxels and if that's your engine? You've absolutely cracked it visual wise. Subscribed.
Love this! I saw some other comments on further ways to optimize traversal & memory usage, but from now on the common term for the 4^3-tree models should obviously be the THC-tree model 😄
The resolution and resource scaling is perfect on this lol. 100% gpu and cpu usage across 32 threads, and 1100fps default window size to 280 at 1440p.
Looking forward to seeing how this project progresses, great job on it!
I think it is amazing what you were able to achieve with the surface normals. Not using polygons frees you of building the chunks with this geometry to render the voxels. Nice idea, really amazing !
I tried the demo, I was quicker than expected. Good work.
Excellent work. I'm happy you went back to ray tracing. It does look much better. I love the idea of using photogrammetry to build out levels. I think this would make a really interesting almost PS1 looking game.
The one frustrating thing with the photogrammetric models is that they are hollow on the inside. It would be really nice to preprocess them so that they are solid (and also have proper normals).
This is so awesome!! The game looks amazing keep going!
Thanks for watching :)
That's a very nice acheivment. Congrat
Oh also wanted to say that I found your channel (which has been great by the way). Because of a random video "You can Parry Nukes" for that V.A. Proxy game.
I thought, Man it would be cool if that slash or explosion could slice a mountain in half as it traveled forward. Then I started thinking of Voxel destruction and how Voxel art would be pretty good for showcasing that kind of destruction. (Even that game looks like it be transformed into a Voxel art style.
Then ended up down a rabbit hole of Voxel plugins for Unreal then custom Voxel engines and such which led me here.
just started my data structure/algorithms course and seeing why the efficiency can be so important even on personal projects is motivating
real scan environment looks so sick. with a little bit of hand finishing it would be an amazing level generation tool
Absolutely 🤗
Absolutely love the photoscans!!! Also, i think the formal term for a tree with 8^3 sized nodes is a B+tree, B as in binary, + as in more than two children.
Love your work. Voxel engines have a nostalgic place for me. Games like the original Outcast or Comanche (this dates me) had astonishing visuals for their time. That a voxel engine was possible on 1992 when barely any games were 3D at all is testment to their potential. There's a certain charm and art style to low res combined with a blocky world that is worth exploring. Bonus if that means it can run on a potato or a very old machine. Great potential there.
Glad you enjoyed the video, and I agree about the nostalgic aesthetic :)
Woooo! He's back at it again with the rewrite! This guy is gonna be the next Notch!
That's the goal!
This is amazing, continue your good work
The low resolution has a really cool old-school feeling to it; you should play around with a CRT post-processing pass, could look awesome with the right resolution settings!
This has to be the most immersive voxel engine I’ve seen so far
One of the things I always wanted in AoS was vehicles. Imagine driving around a map in a Jeep, or driving a self-propelled artillery to a strategic high point? I could never figure out how a vechicle would navigate voxel terrain, but this idea of "normals for each voxel" could make it work.
this looks so good, i find the low resolution version charming
Beautiful work.
Very intresting to watch, thank you
I've always loved voxels, since Ken Silverman's Voxlap engine. I love the destructibility in particular, since polygons can't really do this. I think you have the rare opportunity to push the medium. So if we take the concept of destruction and voxel physics. What other cool things can we do that is only achievable with voxels? What are the limitations with polygons? I really feel like the future of game dev will be in a medium similar to voxels but something like gaussian splatting. Where the engine works with atoms. Maybe it's best to think of voxels as atoms. It's really an exciting area that has been so neglected by developers. You're very lucky to be working in an area that is yet to be fully explored creatively.
Wait a sec.. i recognize you. I used your fork of cpal for getting audio to work on the web in my game engine. Thanks and keep it up with the rust graphics content!!
Yep, that's me! One day I will add audio to my own engine with it too.
Wow, great job! Hope you can also implement reflection and refraction!
Yep! Reflection, refraction, and volumetrics are all stuff that I want to try!
Video quality is great!
considering how fast these engines are at lower window resolutions, exploring upscaling options similar to DLSS might be a valuable win for lower end hardware. i think the nature of voxel scenes could lend themselves extremely well to certain upscaling techniques (or look ugly idk). would be fun to expiriment
I believe the "higher levels" of searching through the voxels is some form of spatial hashing (you "hash" the ray positions to a coarser grid, which is then used to iterate through smaller grids).
that looks amazing!
I really like the low res look, especially if you add moody lighting and fog
Imagine Magic Carpet remake with this tech!!!! Destructable castles, volcanos, tremors, everything. :DD
I love how the game looks on the IC, maybe even better than on the GTX.
damn dude, this is the coolest stuff in CS in my opinion. Such a good combination of math and algorithms/data structures, to make something that looks so cool, and if it wasn't for job prospects, I'd totally go for it. I'm in second year uni, in cs and physics, and I'm so split in what area I want to go in. I worked on my own shitty, completely entry level 3D rendering/physics engine, and it was so much fun. But the game industry is going through so much layoffs right now, and if I want to work on other physics simulations like robotics or autopilots, it seems like I'd need a masters, which idk if I'd go for. I'm so torn on what I should work on this summer, if I should continue working on my game engine, or get into AI which is probably the more employable path, but doesn't seem as interesting as this. Also from what I hear game devs don't earn as much as other software engineers, but I wouldn't call this type of thing "game dev", more like engine designer, right? does it pay adequately to how much work you have to put in? maybe I care about the pay too much...
I think that your concerns about money are understandable. There definitely are game engine and GPU-related jobs out there, but they are competitive to obtain and the games industry doesn't pay quite as well. I'm not sure what advice to give you, other than that I personally would not go into AI. The area is overhyped right now, especially since the field has a low skill floor. Anyway, maybe consider software jobs in other areas related to low-level programming? In addition to games industry jobs, there are positions at companies like Qualcomm and AMD for developing new GPU drivers and tech.
The lower resolution + voxel style together looks very nice. Perfect for lower end GPUs as well like you said.
awesome demo!
Glad you liked it!
Man keep It up! The best voxel engine will be the one that gets published
Haha definitely
just here to say I love the low res look, look like one of those "demake" but with its own style and not just PS1/2 look
The low resolution gives me 90s vibes in a good way.
That church looks oddly familiar 🤔
Hey capslpop! Nice to see you here - I've actually been watching your channel since your first uploads two years ago. The Church of St. Sophia really is a nice test model, isn't it? Your channel was the first place that I saw it :)
Thanks for watching! Can't wait to see what you do in your next video :)!
This is incredible!
wow this looks amazing
Your brick tree is similar to cone marching just in grid aligned space, and could also be thought of as a sort of acceleration structure.
Amazing :) What do you think could be done to prevent the low res version from "flickering"?
Also, how do you calculate the voxel normal? From what I've seen you color the whole voxel one color instead per voxel face, no?
Duuuuuuuuuuuuuude this is awesome.
All these voxel games 😊
Great video! I am curious if you plan on tweaking the shadows and lighting to make it more realistic? I noticed that there is a lot of ambient light being used. Any plans to use a raytracing/phong lighting system in the future?
Yes, I want to experiment with different kinds of lighting in the future. At the very least, I would want to support ambient occlusion and point lights. But having some kind of global illumination or other system would be cool too.
Wow, this is so cool!
11:10 Looks even more nostalgic really.
The photoscan stuff is the best reminds me of Vagrant Story on PS1, some of the best lo-fi graphics ever made!
10k RUclipsrs - "I'll optimize this engine, even with the cost of rewriting 11 thousand lines of code."
Multimillion companies hiring hundreds of programmers - "It reaches 48 FPS on RTX 4090, that should be enough!"
Thank you for the video, it's very informative. Great job!
Very cool dude!
Incredible! 😮
This video was great
could you please go into more detail about per voxel normals? either here or in another video?
I get around 8 fps on integrated graphics in the church which is 8 more than I expected, good work! (laptop defaults to IGPU with chrome)
Wow, that "low resolution" looks very interesting IMO. Idk why, but it reminds me ps1, and it's fascinating that it's all voxels. I think there would be a lot of cases of making use a such style. And it's true pixel-art (without shifting and rotating pixels)
It all looks really good. Will other things, like transparency or volumetrics, be easier with this new method?
Volumetrics will absolutely be easier, since volumetrics involves accumulating the amount of light along a ray! I anticipate that transparency will be equally annoying to implement as in rasterization, just in a different way lol
Fantastic! Is there a game / project in mind for the engine, or are you planning to release the engine itself? Either way, great work and I enjoyed hearing about the more granular GPU challenges and solutions you encountered - thanks for sharing!
My goal is turn to the engine into a multiplayer platform where users can create their own experiences with mods/plugins. The rough project roadmap for me involves three steps. First, I want to finish the core engine. Then, I intend to build a small proof-of-concept game with it, and release that. Finally, I'll release the suite of modding tools and related stuff so that people can build and extend the engine.
@@DouglasDwyer Sounds ambitious! Though you're clearly a very proficient GPU programmer, good luck to you!
Damn, this is impressive.
I think global illumination could really make your engine look *even* better.
I recently learned about an interesting technique for global illumination from a channel called xima. In his voxel engine he is using a cellular-automata based global illumination model that runs in a compute shader(to great effect).
I just learned about Xima's cellular automata GI, and it looks revolutionary! But I'm not sure how it would scale to scenes with more voxels. That said, GI is definitely something that I would like to learn about. I agree that it could take the graphics to the next level on high-end GPUs.
@@DouglasDwyer I don't think the performance impact is as big as you might imagine for this technique. The cellular automata only needs updates when the light conditions change, probably works well with octree-like structures, and lends itself well to caching. Plus, there is really no need to tie the light updates to the framerate, or at any fixed rate. You could just GI-update a small region at a lower rate for lower-end GPUs - due to the cached results for the non-updated chunks performance might should be ok? Really I'm just guessing here, maybe ask him for help? He seemed really nice in the comments where I already asked him some questions along those lines earlier :P
I definitely will reach out to him in the future. What I meant in terms of scale was more referring to memory consumption. Every time you double the size of your scene, it consumes 8x the memory, since the cellular automata requires storing per-voxel data, right? So I wonder how the memory is compressed. But maybe Xima has a solution :)
This looks cool
I'm curious if you have ever tried the BrickMap data structure, which is very similar to yours, but its 8x8x8 instead of 4x4x4, though, I don't believe its organized in a tree structure. Great video as always!
Reportedly a brickmap of individual 64x64x64 octrees can also give great results.
Problem with higher subdivisions is that the bitmask he's using to traverse the tree becomes longer. 8^3 requires that many bits (1024), which is 8x64-bit ints. There's a tradeoff there when it comes to complexity, and it's somewhat hard to try out all the different trees because they all require custom CPU and GPU code so switching between them takes a bit of time.
@Caellyan puts it perfectly here. The 64-tree structure is the optimal size for register usage and empty space skipping, from my experience so far.
Now I really wanna see it with multiple ray bounces. Deeper shadows would go a long way in bringing out the details.
This is nice!
very cool video
I am not sure if it is technically the same, but in uni we were taught the "branch on need octree" which is kind of the tree you are using?
Looks great !
I'm not an english native and not a dev by any mean so I might have missed something in the video, but I was wondering after toying with your mod if you would be able to make a "scale factor" that increases the further a voxel is from the camera, instead of doing the entire screen ? So that tiny voxel cubes we can barely see can be regrouped with other voxels nearby, to make a bigger cube. Hopefully this can allow less calculation to be done afterwards for lighting, "painting the scene" :) Maybe even simplifying physics if the calculations uses big cubes instead of doing it voxel by voxel. Or a combination of both (rendering tiny voxel cubes while doing all the calculation with cubes 2/4/8 times biggers) ?
I honestly dont know, like I said I'm not a dev so it's just wild guesses. But that's what I'd personally do if I wanted to improve performance :D
Yes, your idea is an excellent one! This is called a level-of-detail (LOD) system and I actually did implement one in the renderer (if you look at the montage about 30 seconds into the video I think that you can see it working). But I haven't hooked up the LOD system to the world generator/manager yet, meaning it doesn't work in-game. I am currently adding that feature now!
@@DouglasDwyer Nice ! Thanks for the info. Can't wait for the next video to see more about it :)
god you're so cool, i hope i'm this good at programming one day
Just keep working hard and build new things! You can become an even better programmer :)
@@DouglasDwyer thank you! your channel, and many other programming ones, are very inspiring to me haha
Amazing work! I think you might have found the method Euclideon unlimited detail uses...
Cool video!
I'm glad you enjoyed it!
I could run it with const 15-16-17ms in my browser on any map with any quality of rendering and all, so I think it is working pretty well on external graphics cards as well (I have an old AMD one). Curious to see how it would perform under stress or with more features like physics and all
And talking about physics, don't you think the old rasterization way of doing thing would be easier to integrate than with the new raymarching way? I mean because you would be able to kind reuse the render meshes as collision meshes and all, or are you planning to go with a more voxel-friendly approach for collisions here?
Excellent question, and thanks for trying the demo.
The voxel physics has always used the voxel data itself for the collisions, so there won't be any problems there! That said, I am planning to redo the physics system since my first attempt was a bit crippled. I learned a lot making it, and I hope to create a much better result this time around.
Amazing!
This is so impressive dude! Is the brick tree only a 2 level tree? How do you handle off grid voxels and all that? At a high level obviously.
Here is a rough diagram of my rendering data structure: imgur.com/a/P5cldl2
It's a bit outdated - I now use linear arrays rather than linked lists to store objects.
In short, my voxels are organized into 256³ chunks - so each chunk is a 4-level 64-tree. Non-grid-aligned objects are stored as a list of indices on each chunk, and are ray marched independently before ray marching the main chunk :)
@@DouglasDwyer Man thank you for this, I love seeing how other people imagine solutions for these problems, very cool!
Fantastic! Why oh why don't we see more retro-style games using voxels? I guess the engine programming is difficult and non-standard, but old games like Outcast and even older games like Ecstatica were fantastic, and the low-rez example in the end of this video reminds me a lot of Ecstatica for example. More! More!
11:08 super cute, love it
Looks really good 😊 I wonder if you could get the empty space traversal even more memory compact with something like a Bloom query
Thanks for watching! What's a Bloom query? Usually, the best traversal data structures are those which directly encode the positions of the objects into the structure itself. Trees are a great example of this because the position of a node in memory is directly related to its position in 3D space.
@@DouglasDwyer Like a Bloom Filter, but using a compact lossy encoding of the vector entering the block- giving a fast no-hit/maybe-hit first test. No idea if that would end up better or worse. Would probably help most near large flat areas.
this is fucking insane Douglas
ok, you've conviced me to look harder into making my own engine. I am an unreal engine programmer so my current knowledge set is locked within that engine. need to expand man, but feels like there is little out there
Good luck!