Vecvec

> Added one in `Device::create_acceleration_structure()` but unfortunately that was not it either That's annoying, I wonder what it could be > I would say we try to land this PR...

Although setting `TLAS` dependencies and only stating that we are using the `BLAS`es contained in them is good for optimization, the current implementation will not work due to it being...

> Instead of calling it inside command_encoder_build_acceleration_structures() we could call DynAccelerationStructure::set_dependencies() in Queue::submit(). I think there would still be issues where you encode the build after a use of the...

Actually I've found something called a [`MTLResidencySet`](https://developer.apple.com/documentation/metal/mtlresidencyset) which seems like it could be used. I need to investigate it further, but it seems like you could keep one per command...

> This might already be wrong in other aspects unrelated to this PR, like the validation layer and how it sees the dependencies. Yep, this has been pain for me....

> Acceleration structures don't work in headless mode That's an odd driver bug, I wonder how it's caused... On another, completely unrelated, note, I've been looking at the possible ways...

It's blocked on https://github.com/gfx-rs/metal-rs/pull/361. There also sounds to be some driver issue which only makes acceleration structures work when a window is there. @Lichtso would probably be able to give...

> Re: residency - could you call useResource? I think I mentioned this earlier, but it must be in some review comment. We can't due to allowing out of order...

> [MoltenVK](https://github.com/KhronosGroup/MoltenVK) has not implemented ray tracing either: (see https://github.com/KhronosGroup/MoltenVK/issues/427 and https://github.com/KhronosGroup/MoltenVK/issues/1956). Or were you thinking about another translation layer / project I was thinking of Game Porting Tool Kit,...

@Lichtso did you file a bug with apple for acceleration structures not working w/o a window? It would be good to keep an eye on it in this PR (or...