X-Plane 11 Working On New Physics & Other Improvements, Vulkan Taking More Time

[phoronix]

Phoronix: X-Plane 11 Working On New Physics & Other Improvements, Vulkan Taking More Time

Earlier this month the Laminar Research crew responsible for the realistic, cross-platform X-Plane flight simulator presented at the FlightSimExpo about their work on porting the flight simulator to Vulkan and other ongoing improvements...

http://www.phoronix.com/scan.php?page=news_item&px=X-Plane-11-Summer-2018-Status

[Dedale]

I know they are primarily Mac users but i still wonder why they support metal rather than MoltenVK ?

[Zoll]

Mac users compromise a big chunk of their users. Linux users around 0.9%. I believe they would use MoktenVK for Mac, but in case Apple pulls the plug and introduce some breaking change, they can rely on Molten backend. Vulkan would be used for all platforms, it makes sense for them. The only danger is stemming from Apple at this point.

[smitty3268]

I know they are primarily Mac users but i still wonder why they support metal rather than MoltenVK ?

You just answered your own question.

Anyway, if you look at the blog post it says that they are creating a higher level engine that will then just have 2 backends - one for Vulkan and one for Metal. Given the relative similarity between the two API's I imagine they figure it won't be that much work to maintain both, and it means they don't have to pull in a big 3rd party dependency to translate stuff for what is, after all, their primary platform.

[mike44]

Does Aerofly use MoltenVK on Mac?

https://www.avsim.com/home/pr-ann/aerofly-goes-vulkan%EF%BB%BF-r4761/

Cross fingers they might bring it also to Linux.

smitty "they don't have to pull in a big 3rd party dependency to tr" what do you mean? Vulkan layer seems very small and fast:

https://www.phoronix.com/scan.php?page=article&item=dota2-mac-vulkan&num=2

[Dedale]

All i know is they said they would port it on Linux and they asked for a couple beta testers on steam.

https://www.gamingonlinux.com/articl...age=2#comments



I am speaking of Aerofly FS2

[smitty3268]

smitty "they don't have to pull in a big 3rd party dependency to tr" what do you mean? Vulkan layer seems very small and fast:
https://www.phoronix.com/scan.php?pa...c-vulkan&num=2

The current version of MoltenVK is 5.77MB. I agree that's not exactly enormous considering what it does, but it's still almost 6MB of compiled code that you haven't written and have imported into your app and then have to support if there are any bugs.

A library that implements the entire API is by definition larger than one that implements only the bits of the API that X-Plane cares about. A lot of what makes something like MoltenVK hard to implement is it has to work with everything, no matter how you are using the API and which bits. X-Plane will presumably have the benefit of only using specific portions of the API in particular ways which are easy for them to implement themselves.

Then there's the possibility that Apple might just up and ban MoltenVK apps one day. It seems fairly unlikely, but you never know and I think you have to at least consider the possible risks when you are attempting to sell a product. That's a different risk for a company like steam that gets marginal sales on MacOS and just wants to port apps there vs one like X-Plane where OSX is their bread and butter.

None of that is to say I particularly agree with them about this. I think MoltenVK would absolutely do the trick here, and probably result in less work for them. I can only say that i understand where they are coming from, and that they aren't being crazy. The truth is that they'd probably drop the Vulkan support before Metal, and stick Linux users with the old OpenGL support forever.

[mike44]

Vulkan is also used for Windows and mobile.-