Re: [Flightgear-devel] Unreal Engine 5 and Antoinette Project

[Stuart B. <stu...@gm...>]

Hi Folks,

I've been busy on WS3.0 so haven't had time to post until now.  Given my
involvement in both FlightGear graphics and HLA, I felt I should probably
comment!

On Mon, Oct 24, 2022 at 8:20 AM Salvatore De Astis wrote:

> Thanks everybody for your answers.
> I've been working in CAE for 12 years and all the simulators there had the
> Image Generator fully decoupled. So it was a standalone product made up of
> hardware and software which CAE was also selling separately. All the
> communication between the simulation and the IG was going through a custom
> protocol over ethernet for all the things which were supposed to go at 60hz
> many others like weather, air and ground entities etc., were entering in
> the ig through gateways process able to fetch those data from HLA or direct
> communication.
> A design like this would be ideal in the future, moving to
> VulkanSceneGraph for instance, Flight Gear could use the rendered in a
> decoupled mode. And ideally in this way FG might be connected to any type
> of Image Generator much easier.
>

I did some prototyping work to federate FlightGear within HLA a number of
years ago, using OpenRTI and SimKit.  There should be some reference in the
mailing list archive if you care to look.  It is certainly possible, and
one use case was to decouple the IG and enable work to start using VSG
while continuing to support OSG.

It's interesting that you comment "All the communication between the
simulation and the IG was going through a custom protocol over ethernet for
all the things which were supposed to go at 60hz".  Are there specific
reasons why you would not choose to drive everything over HLA and have the
IG a HLA delegate?  Perhaps performance?

I should also point out that FlightGear is used regularly as a decoupled
Image Generator for both academic and industry projects, through the many
flexible I/O options available.  They just aren't publicised much.

There has been some work on how we might move to VulkanSceneGraph, but last
I heard there were some technical problems we couldn't overcome.  Fernando
will know more, but I haven't heard from him in a while.

Best regards,

-Stuart