It's been awhile since I've done game engine work, but is this impressive? The first thing that comes to mind is they're using instanced rendering. This allows the CPU to only deal with 1 sprite, while telling the GPU to render multiple instances of the sprite, and use a GPU buffer to find each sprite's transformation matrix. All the CPU has to do is update that mmap'ed buffer with new position information (or do something more clever to derive transformations).

Am I missing something that makes the video novel?

Nice demo! We need more of this approach.

You really can achieve amazing stuff with just plain e.g. OpenGL optimized for your rendering needs. With todays GPU acceleration capabilities we could have town-building games with huge map resolutions and millions of entities. Instead its mostly only used to make fancy graphics.

Actually I am currently trying to build something like that [1]. A big big world with hundreds of millions of sprites is achievable and runs smoothly, video RAM is the limit. Admittedly it is not optimized to display those hundreds of millions of sprites all at once, maybe just a few millions. Would be a bit too chaotic for a game anyway I guess.

[1] https://www.youtube.com/watch?v=6ADWXIr_IUc

Very rough guesstimates:

200000 * 200 * 2 = 80M tris/sec

200000 * 200 * 32x32px = 40 gpix/sec (if no occlusion culling)

Neither of those numbers are particularly huge for modern GPUs.

I'd wager that a compute shader + mesh shader based version of this could hit 2M sprites at 200 fps, though at some point we'd have to argue about what counts as "cheating" - if I do a clustered occlusion query that results in my pipeline discarding an invisible batch of 128 sprites, does that still count as "rendering" them?

Using Goroutines, I also made 10k 2D rabbits wander on a map for 5% of my laptop cpu (they'd sleep a lot admitedly). One goroutine per rabbit, how amazing when you think about it. That's when Go really got me.

edit: oh they do rabbits in the video as well what a bunny coincidence

edit2: the goroutines werent drawcalling btw, they were just moving the rabbits. The drawcalls were still made using a regular for loop, in case you wonder.

This by the looks of it is in Jonathan Blow’s Jai language.

How are you finding working with it? Have you done a similar thing in C++ to compare the results and the process of writing it?

200k at 200fps on an 8700k with a 1070 seems like a lot of rabbits. Are there similar benchmarks to compare against in other languages?

Neat. Isn't this akin to 400k triangles on a GPU? So as long as you do instancing it doesn't seem too difficult (performance wise) in itself. Even if there are many sprites, texture mapping should solve for the taking pixels to the screen part.

My guess is that the rendering is not the hardest part, although it's kinda cool.

Bit of a tangent and useless thought experiment, but I think you could render an infinite amount of such bunnies, or as many as you can fit in RAM/simulate. One the CPU, for each frame, iterate over all bunnies. Do your simulation for that bunny and at the pixel corresponding to its position, store its information in a texture at that pixel if it is positioned over the bunny currently stored there (just its logical position, don't put it in all the pixels of its texture!). Then on the GPU have a pixel shader look up (in surrounding pixels) the topmost bunny for the current pixel and draw it (or just draw all the overlaps using the z-buffer). For your source texture, use 0 for no bunny, and other values to indicate the bunny's z-position.

The CPU work would be O(n) and the rendering/GPU work O(m*k), where n is the number of bunnies, m is the display resolution and k is the size of our bunny sprite.

The advantage of this (in real applications utterly useless[1]) method is that CPU work only increases linearly with the number of bunnies, you get to discard bunnies you don't care about really early in the process, and GPU work is constant regardless of how many bunnies you add.

It's conceptually similar to rendering voxels, except you're not tracing rays deep, but instead sweeping wide.

As long as your GPU is fine with sampling that many surrounding pixels, you're exploiting the capabilities of both your CPU and GPU quite well. Also the CPU work can be parallelized: Each thread operates on a subset of the bunnies and on its own texture, and only in the final step the textures are combined into one (which can also be done in parallel!). I wouldn't be surprised if modern CPUs could handle millions of bunnies while modern GPUs would just shrug as long as the sprite is small.

[1] In reality you don't have sprites at constant sizes and also this method can't properly deal with transparency of any kind. The size of your sprites will be directly limited by how many surrounding pixels your shader looks up during rendering, even if you add support for multiple sprites/sprite sizes using other channels on your textures.

i finally got around to writing an opengl "bunnymark" to check how fast computers are.

i got 200k sprites at 200fps on a 1070 (while recording). i'm not sure anyone could survive that many vampires

Does this work with large semi-transparent objects? (My 10-year-old experience with 2D game engines was that 10k objects wasn't really a problem, unless you were trying to make clouds or fog from ~200x100px sized, half-transparent images. Have a 100 of those, and you'd run at 5 FPS.)

I assume each sprite is moved on the CPU and the position data is passed to the GPU for rendering.

Curious how you are passing the data to the GPU - are you having a single dynamic vertex buffer that is uploaded each frame?

Is the vertex data a single position and the GPU is generating the quad from this?

How much time is spent in Jai? How much time is spent presenting the graphics? Unfortunately, graphics benchmarks like this are hard because they don't tell us much. You have to profile these two parts separately.

Gotta be honest this is beyond my current comprehension, but seeing the visuals on this while stoned was a trippy pleasure.

Yes although the performance is probably largely due to occlusion? Also the sprites do not collides with their environnement

Is there a way to do it as 1 sprite with 200k SVG filters applied to it at 1fps?

Anecdote: In Unity, using DrawMeshInstancedIndirect, you can get >100k sprites _in motion_ and still maintain >100 FPS.

Using some slight shader/buffer trickery, and depending on what you're trying to do (as is always the case with games & rendering at this scale), you can easily get multiples of that -- and still stay >100FPS.

I agree, more of this approach is great. And I am totally flabbergasted at how abysmally poor the performance is with SpriteRenderer Unity's built-in sprite rendering technique.

That said, it's doable to get relatively high-performance with existing engines -- and the benefits they come with -- even if you can definitely, easily even, do better by "going direct".

> We need more of this approach.

1000% agree.

I recently took it upon myself to see just how far I can push modern hardware with some very tight constraints. I've been playing around with a 100% custom 3D rasterizer which purely operates on the CPU. For reasonable scenes (<10k triangles) and resolutions (720~1080p), I have been able to push over 30fps with a single thread. On a 5950x, I was able to support over 10 clients simultaneously without any issues. The GPU in my workstation is just moving the final content to the display device via whatever means necessary. The machine generating the frames doesnt even need a graphics device installed at all...

To be clear, this is exceptionally primitive graphics capability, but there are many styles of interactive experience that do not demand 4k textures, global illumination, etc. I am also not fully extracting the capabilities of my CPU. There are many optimizations (e.g. SIMD) that could be applied to get even more uplift.

One fun thing I discovered is just how low latency a pure CPU rasterizer can be compared to a full CPU-GPU pipeline. I have CPU-only user-interactive experiences that can go from input event to final output frame in under 2 milliseconds. I don't think even games like Overwatch can react to user input that quickly.

The upper rendering limit generally isn't explored deeply by games because as soon as you add simulation behaviors, it imposes new bottlenecks. And the design space of "large scale" is often restricted by what is necessary to implement it; many of Minecraft's bugs, for example, are edge cases of streaming in the world data in chunks.

Thus games that ship to a schedule are hugely incentivized to favor making smaller play spaces with more authored detail, since that controls all the outcomes and reduces the technical dependencies of how scenes are authored.

There is a more philosophical reason to go in that direction too: Simulation building is essentially the art of building Plato's cave, and spending all your time on making the cave very large and the puppets extremely elaborate is a rather dubious idea.

Is this not done because of technical limitations, or is it just not done because a town building game with millions of entities would not be fun/manageable for the player?

Although, there's a few space 4x games that try this "everything is simulated" kind of approach and succeed. Allowing AI control of everything the player doesn't want to manage themselves is one nice way of dealing with it. See: https://store.steampowered.com/app/261470/Distant_Worlds_Uni...

I immediately thought of the bullet physics games like gradius, parodius, raidan, r-type.

What made it of course was the art. An army of digital illustrators working by hand to create bitmaps that pop.

One pseudo 2.5d game I'm playing now is Iridion 2 GBA (2003). You can see the care taken with the art design team, pure lovers of the genre ;)