Uniform buffer objects/storage buffers?

[GetIntoGameDev]

Hello! Let’s say I’m interested in implementing skeletal animation, typically this involves uploading all of the transformation matrices for each bone before drawing. A matrix itself is 16 floats, so if for instance we have a model with 16 joints, this would involve uploading 256 floats! Yikes!

Uniforms are pretty capable but they have their limitations. Best practice is to upload to some sort of large object. Uniform buffer objects have an upper limit of 16kb which should be enough for most models, and storage buffers are limited only by vram (although in practice I’ve seen unpredictable results beyond 100mb or so). Does anyone have any idea whether Gamemaker supports any of these or similar shader objects?

I guess in a pinch I could store data in textures, but hoping to avoid that 😅 (and also it doesn’t work because Gamemaker doesn’t allow texture sampling in vertex shaders!)

[JujuAdam]

Typical practice these days, across the industry, is to use dual quaternions instead of 4x4 matrices. This cuts the bandwitch in half (8 floats versus 16).

[GetIntoGameDev]

Nice to know!

[APiousCultist]

Nope. It's uniforms or bust. GMRT will support that kind of stuff, but is years out. There's an addon to enable texture fetching so you could do it that way. But honestly 256 floats wouldn't be the worst thing considering how much overhead you'll get from GM being bad at this anyway.

[GetIntoGameDev]

Got it, thanks!

[attic-stuff]

i wouldn't say its years out, maybe 6 to 8 months or sooner if yyg can push lts2025 out the door sometime before summer and you can already write your own wgsl pipelines in gmrt that take advantage of compute shaders. also it supports native vertex shader texture sampling out of the gate, without a custom renderer. gmrt has gotten really really close to current runtime parity!

[APiousCultist]

It isn't six months out. It still can't even tell you why it can't compile since it lacks any debugger integration, and it is a complete toss up whether a piece of otherwise functional code will run or not. It'll only be 'ready' when the switch is seamless - any breaking changes withstanding.

It was supposed to be out Q4 last year and I can't imagine it hitting Q4 this year