Combat-Helo to use HTR for advanced flight model

In case you don't follow the dev blog I'm happy to formally announce that Combat-Helo will be using Fred Naar's Helicopter Total Realism (HTR) physics module for the advanced flight-model.

The data driven flight model uses advanced blade-theory derived from works such as Wayne Johnson's Helicopter Theory and others. The model can process different helicopter configurations, standard, tandem, co-axial and it's flexible allowing for constant adjustments to CoG, payload shifting and stabiliser airflows.

HTR is currently available as an external module for FSX and interfaces via FSUIPC. Details in the forums at Hovercontrol.

Great news!!

This bit of software has huge potential in FSX, but outside of the limitations of FSX this will be amazing!!

Better crack on with the Cockpit!!

Rich

Interesting.. reading through his forum now.

Great news! I love newest iteration of HTR in FSX. Combat-Helo is going to be good

There's quite a lot we can do, visualising the flight model, plotting performance graphs based on current configuration. I'm quite keen on adding a graph for debugging so we can compare the model with published data.

Quite excited by it myself. I left the current FM in a not very complete state while I pressed on with all the necessary game bits, cockpit logic, MPDs etc.

How would you simulate battle damage components?
I presume you will have a way of triggering the HTR failure mode (didn't see a 'pilot incapacitated' mode)?

What about the weight/drag difference when stores are fired/jettisoned?
Although I'm not sure if that would make a perceptible difference in the sim.

On a slightly related note, I saw on TV [it must be true ] that when some of the old wooden battleships fired a full broadside, they would loose about 1/2 ton weight in shot fired!

ps: has anyone tried aerobatics with the HTR?

Well, out stores class updates the payload weight for each pylon. And we calculate the weight of the fore and aft tanks, these things change the CoG which should be reflected in the model.

There's quite a difference in weight with a fully loaded Apache, the performance changes will be quite noticeable especially near critical density altitudes.

Failure modes will be built into the sim rather than executed an external program (such as is done by HTR with FSX). The way the helicopter states are accessible via the network means pretty much everything that can be controlled in the helo can be done remotely including flipping switches and failures.

that's great to hear!

Sounds like it's going to be a fun one to fly.

Regarding engine performance, are you modeling the US and/or British Apache?

American, both inside and out.

Cheers

S~ Flex,
I apologize if what I'm asking is a repeated question, but reading about the complex flight model, and looking at the terrific graphics work being done makes me wonder what it will take to drive this thing. Is Combat-Helo coded for 64bit? Will it require a multi-core processor for best performance? Will it require a minimum of a 512mb GPU? DX-10?
thank you,
Flyby out
ps glad to see you back at it again. I recall images from your early efforts at the Apache Longbow long ago. I was drooling then (as now).

Specs should be fairly reasonable. We've been developing on Nvidia 9800's although Richard just splashed out on a GTX 460. The engine is OpenGL and I believe we're aiming to support 256MB cards but that may change by the time we're ready to release.

We're continually optimizing both the code and the artwork for maximum efficiency. Currently, with a 6KM draw distance and 1280x1024 res I get 80-90 fps on foot and 40 fps in the pit with the TADS turned on. Over Herat City frame rates tend to drop by about 30%.

It'll be interesting to see how much frame rates suffer when we get ground units moving and the action heats up.

Cheers

Since the engine is OpenGL can we expect a Mac and or Linux client down the road?

The Leadwerks engine has yet to be ported to Linux or Mac as far as I'm aware. The next major iteration of the Leadwerks engine (version 3) will apparently be much simpler to port so there is future potential to bring out Combat Helo on Mac or Linux.

Cheers

Indeed, we're watching developments of the new iteration of Leadwerks engine eagerly, it's a GPU heavy engine, a Mac version will rely heavily on what video chip is inside it. Recently they've been putting in some decent nVidia hardware. The new Leadwerks engine is a year away at least.

Other than the 3D engine and Raknet we use cross-platform libraries, I have some ?win32 specifics in line but nothing that can't be ironed out. So maybe, a year or so ahead. Don't hold your breath.

I'm not just would be nice to get rid of Windows that's all . Keep up the hard work guys looking forward to the sim. Definitely a day one purchase for me.

Sorry for bumping an old topic, but this would save me making a new one on the same subject.

As mentioned here, the HTR physics will be used to model the FM and response of the Apache. Recently I've started using FS9 with HTR to fly the Hovercontrol helicopters and I noticed a huge difference between HTR (set to 100% realism and proper sensitivity settings) and FS9's default FM for helos.. Let alone the difference between HTR and Arneh's EECH FM. So my question is, will controlling the Apache be as hard tho realistic as controlling the Hovercontrol Bell 412 PE with HTR for instance? Or will there be a simplified FM for the sake of amusement? I really hope the first is the case here.. But that would mean that all of us (including me) who think they can handle a helo in games like DCS:BS, LB2 and EECH will look like utter noobs after finding out what it means to fly with HTR.

It will be playable by mere mortals I promise. HTR in FSX is kind of hampered by what FSX lets you control, not much focus was put on on FMS systems since it was mostly written for light helicopters. But it does have some excellent dampening functions (tell it to bring the helicopter to a hover and watch the 'AI' pilot take over). It also depends on the profile data you use, typically it gets refined by actual pilots in a back and forth manner till everyone is happy.

If you need to, you will be able to pick up an XBOX joypad and tool around if you so desire using a special input mode written for that kind of device.

They should just convert the public NASA Ames Research Center/Sikorsky GenHel flight model from Fortran to C++ and use that. Start out with the Blackhawk and then modify GENHEL to get the performance of each new helo they add after that.

The master has spoken. Listen. And listen good.

Penn State started doing a crude C++ conversion but I'm not sure if it was finished or perfected. The original Fortran version should be available to the public, at least in the USA. I will get in contact with some people and find out how far along the conversion ever got and who to contact to get the original Fortran. Once converted, all that is necessary appears to be the graphics and interface systems. Penn has previously had the Fortran running in Matlab and then interfaced just with FlightGear.

If simhq.com users with coding experience, Combat Helo's peeps, and DCS/ED coders can all band together to work on a line-by-line conversion and offer it back to the public, there is little reason not to. And then this final result can be utilized as-is or modified further to fit the performance capabilities of various other helicopters in commercial and non-commercial efforts.

I've sent some emails off and I'll see who needs to be contacted and what sort of agreements need to be signed. It's been stated several times by Penn, though, that GenHel is publicly funded and publicly open model of the Blackhawk. Just the last correspondence I've seen from them stated they were looking into possible export restrictions before they simply posted the original and their imperfect conversion efforts on the web. Considering DCS is run by a former CIA analyst and they make a National Guard A-10 simulator, I doubt there aren't ways to deal with even those in spite of them being based in Russia.

We have an enormous resource of people on this website that I would argue goes far beyond the coding expertise of one university academic engineering department. They and the helo simulation community as a whole would benefit from the efforts. There are so many disparate efforts on helos and it'd push this area much further if these were unified with a common goal.