AH-64s IHADSS (short analysys of that simulation problem)

[Sundowner.pl]

1. The real life:

 

When AH-64 Apache came to service, the biggest innovation of its design was not the hellfire weapon system, not the high agility, nor the exceptionally high survivability. It was the Integrated Helmet And Display Sighting System (IHADSS for short).

 

 

 

 

 

 

Not many people know, that when Apache was born, other team at Lockheed Martin was working on similar system, for the highly successful light fighter - the F-16. Although the "Falcon Eye" system, was finished, tested, and amazed every test pilot, that flew with it, the IHADSS was the only helmet mounted sight system, that feed pilot with Infra Red Imagery of the world, and still is, although other systems with newer airplanes are entering service right now.

 

Why Infra Red ? Why not less sophisticated Night Vision ? The answer is simple, IIR (Imaginary Infra Red) works all the time, round the clock, no mater if there is sun, moon, stars, or non of them. It sees the objects radiated energy, not the reflected one, and its more prone to be blinded. On battlefield, the lighting changes constantly, even though night vision technology is nearly 70 years old, it still have problems with being blinded by instantly changing lightning conditions. Yet IIR is still costly and heavy.

 

 

2. The simulation:

 

Now let's take a look at ALL helicopters simulations, that were done till today. Did any one of them included realistic made IHADSS system ? No. Not even one. Why is that ? Is this lack of data ? No. Is it the complicity of the system alone ? Nope.

 

The problem lays within the game engines. How many view points a human being have right now ? Two, the left, and right eye. Because we still use 2D monitors those two viewpoints are compressed into one, and projected into monitor screen. What IHADSS do is adding another view point, heck, now there's two too many ! That IHADSS view point is 2 meters ahead of pilot head, outside of cockpit, where PNVS or TADS cameras are located.

 

What every up to date simulations did? Well made the whole world outside the cockpit green and bright. Is this what an Apache crew really see ? No, not at all.

 

What do crew see is a cockpit, and world outside in their left eye, and really odd world in greenish colors, the brighter, the hotter objects are (until he changes the polarity that is), plus the generated symbology.

 

 

3. What have to be done ?

 

So, what do simulation engine have to do, to represent this rather realistically? In two words: A lot!

 

The game, have to generate an image, from the 'left eye', that’s nothing special, it does it all the time. Next it have to generate the IR image from the second viewpoint (PNVS or TADS).

 

Then combine both images overlaying the IIR over natural vision, and making the IIR semi transparent. A heck load of calculations... and is it the end ? Hell no! The Helmet mounted display is, like all HUD sights - collimated image, set to infinity, so you really don't need to adjust depth with your eye. But the other eye is a problem.

 

First: the dominance of the eye. Each one of us have one eye dominant, just like with hands... and legs (who's snowboarding knows that), now every Apache pilot have to be or become right eve dominant, that’s where all the important data is displayed etc. So the rendered image will be, somewhat 80/20 – 80% IHADSS, 20% normal (left eye) vision.

 

Second thing is, if we’re actually not paying attention to what our other eye is seeing, when the other have different image – the image from not used one is blurred (everyone who’s shooting anything with a scope noticed that). So the natural view (the background) will have to be blurred.

 

Third: we actually can chose, and switch dominance on conscious level. Shift between noticing what we see with each eye. With only one image, we have to have some control to be able to switch between those views, some sort of assignable axis, to gradually switch the dominant viewpoint between simulated pilot eyes, from left, to right, from 80/20, to 20/80, and blur/unblur left eye images.

 

That’s a lot of things to take into account isn’t it ? Well guess what, it ain't over yet! Here comes the fun part. The IIR image in AH-64A Apache have rather low resolution, very similar to movies on youtube, enough to see everything, and quite natural if projected at the eye. Yet not really good if we want to project such thing at 19” 1280x1024 or bigger screen. The IIR image have to be made ‘soft’ – as it’s perceived by the real pilots, What that ‘soft’ will mean… well that’s something that have to be made by trial and error process, a blurred edges might be a good start.

 

4. How to do it?

 

Really, I’m not the one paid to figure that out. I’m just showing the complexity of a problem. Yet I wish luck to those programmers who will have to crack it. But I’ll give you a hint, both views don’t have to be rendered on the same computer ;)

[TheProphet]

You have really good point there, a very intersting read. (altough I knew about this feature on the Apache)

Making the AH-64 flyable is going to be a big challange (and not only because of this), but looking (from the side, I'm not a beta tester or played the game) of what ED did with the Ka-50 I can say that I count on them to do a good job with it.

[joey45]

very intresting post...

[Yellonet]

It should be done with just a circle on the right side of the screen that displays the image from the thermal camera - slightly transparent - the rest of the screen

displays what your eyes are seeing. Now you just look in the sight or not, just like in real life.

[Sundowner.pl]

I have high hopes for the Alpha Apache also.

 

I'm not really worrying about the flight model (just remember that the tail is also an AIRFOIL!) , nor the armament, or navigation systems, those are really nicely covered in several books, web pages, and the manuals are available to the public. What I'm really worrying about is that one particular system.

 

Like I wrote, it was never done even remotely right, so there's a challenge. When I go back in my memory to all the games I played for last... 18 years... non of them had such complicated rendering needs. Of course, the rendering two images, for two different viewpoint were made pretty soon - almost all helicopter sim had this for the MFD image. But making both full screen with additional effects like blurring, transparency etc. It's going to be really ground breaking.

 

Yellonet, no it shouldn't be made like you suggest. A simple test, look at the computer screen, an put your hand in front of your left eye, you'll see that you can't see both images, your brain have to choice which image it want to perceive, mainly because both need different depth adaptation of the eye. With IHADSS, the thermal image is collimated, set to infinity, and as long the second eye, also need that (looking faaaar away) you can perceive both images - yet the brighter still win. When inside the choppers cockpit, you have to set your depth perception to very close, to see the instruments, so this reacquire to make a choice - do you want to concentrate on the right eye image, or the left one? You can't have both - one must be dominant, and both have to become full screen in simulation with just different sets of transparency.

[VMFA117_Poko]

I don't remember title but there was a movie with Nicolas Cage in Apache pilot role where was shown left dominant eye trouble and a way to get used to right eye as a dominant.

[joey45]

wings of the apache...

 

great film, trying to find it on dvd...

[JaNk0]

Ha i've seen that movie. It's when they play Indians n cowboys and he starts moving with his feets when aiming, right?

 

Anyway...interessting post. GA and I had a discussion over this, and he said that it would be cool if you can look in TADS with your TrackIR. Maybe that's one way solving this "problem"?

[Sundowner.pl]

Hehehe, If you won't find the "Wings of Apache", try "Fire Birds"

 

 

[joey45]

Hehehe, If you won't find the "Wings of Apache", try "Fire Birds"

 

thanx

[Yellonet]

Yellonet, no it shouldn't be made like you suggest. A simple test, look at the computer screen, an put your hand in front of your left eye, you'll see that you can't see both images, your brain have to choice which image it want to perceive, mainly because both need different depth adaptation of the eye. With IHADSS, the thermal image is collimated, set to infinity, and as long the second eye, also need that (looking faaaar away) you can perceive both images - yet the brighter still win. When inside the choppers cockpit, you have to set your depth perception to very close, to see the instruments, so this reacquire to make a choice - do you want to concentrate on the right eye image, or the left one? You can't have both - one must be dominant, and both have to become full screen in simulation with just different sets of transparency.

Mmm... yeah, if you look at the circle you will see the thermal image, if you look beside it or "through" it you will see the cockpit or outside... I don't see what the problem is... you don't need to have all images full screen, the image from the thermal camera is not full screen as you can - while looking at the thermal image - still see your surroundings, just not in focus, it would be exactly like that on the monitor, you choose either to look in the sight or not.

[Kusch]

I don't remember title but there was a movie with Nicolas Cage in Apache pilot role where was shown left dominant eye trouble and a way to get used to right eye as a dominant.

 

wings of the apache...

 

great film, trying to find it on dvd...

 

 

Fire Birds ;)

 

 

Some screen Sundowner posted here:

 

http://81.210.9.116/~apacz/smf/index.php/topic,6921.msg93434.html#msg93434

[VMFA117_Poko]

Mmm... yeah, if you look at the circle you will see the thermal image, if you look beside it or "through" it you will see the cockpit or outside... I don't see what the problem is... you don't need to have all images full screen, the image from the thermal camera is not full screen as you can - while looking at the thermal image - still see your surroundings, just not in focus, it would be exactly like that on the monitor, you choose either to look in the sight or not.

Yeah. Good point again Yellonet! Looking in the middle of monitor you also don't see sharp edges of the screen, right? It's gonna be well done IMHO. Don't worry Sundowner.

 

[EDIT] True. That was "Fire Birds". Translation is always a problem when recalling the title. Expecially in Poland :D

[Sundowner.pl]

hehehe, I'm not worried, of course if you look (like move your eyeball, not your head) off the HDU colimation screen, you will see other things. But we don't simulate hose movements, because there's no way we acouly could.

 

I'll run my Photoshop and try to emulate how this should look like (at least remotely), I just have to find few shots of apache cockpit form some sims.

[joey45]

it was renamed Wings Of The Apache in this Country.

[Sundowner.pl]

 

It took me some time to not-find good AH-64 cockpit shots from simulators, so I run the FSX, and took two shots, one from VC (night), and one from 2D (day). So the 'IR image' is way off, the symbology is not exactly the same size as the original, and the font is wrong. Yet the resolution of that image is near correct. And this is with 40% transparency.

[Ratgnagna]

It took me some time to not-find good AH-64 cockpit shots from simulators, so I run the FSX, and took two shots, one from VC (night), and one from 2D (day). So the 'IR image' is way off, the symbology is not exactly the same size as the original, and the font is wrong. Yet the resolution of that image is near correct. And this is with 40% transparency.

Hello!

Where to found this Addon please?

Thanks. :)

[Sundowner.pl]

It's Alphasim's - it's payware,and I don't recommend getting it, there are many bugs, like the upper left console missing.

[Ratgnagna]

Ok, thanks a lot! :D

Bad product for a payware... ^^

[GGTharos]

You guys should be hapy to know that the current NVG's in BS work very close to the way you guys have described as being the 'desired mode of operation'...or maybe exactly like it. :)

[Weta43]

(posted & GG's Beat me to it)

Or they could just do what you've done there & generate an image that looks like an overlay of a circle of the infra-infra-red image + display info (no more tricky to implement than the mini-hud available in LO) at 40% transparancy over the standard image moving with head movements.

It wouldn't be that complicated - there are no real colours in game it's all calculations so there's not a lot of diference between attributing colours based on one palete versus another - like the NVG modelled for the Ka-50.

If there were a real desire to create the effect of one image being focused at infinity when dominant & the other at a meter or two, you could just keystroke toggle between all the 'non-green' info could having a blurr thrown over it & the 'green' info being out of focus... That would realy be the only thing to it that's not already modeled in BS to some extent - blurring one palete while not the other

[Sundowner.pl]

In BS, from what I saw in videos and screenshots its really nicely made. Yet why is it black&white ? Every Russian NVG and NV scope I saw working (mostly gen. 1 and 2), was just like western - greenish. But in BS we have NVGs - the view point is the same, and is based on what pilot see anyway (only greenish and way brighter - that's the way NVG work). For PNVS - first the overlapping view is further away, and what it sees (IIR) is not rally what the game normally generates.

 

Actually, for those that do have Flaming Cliffs. The IHADSS would be an image like that from Mercury FLIR Pod, but shaped similarly like the BS NVG, with all the stuff I mentioned earlier. And by the way I think that ED, when working on the new engine, should take special care of the IR image. It will need probably some sort of additional maps for objects - thermal maps, that would specify how things would look like in IR - which part should be hotter, which one should cool faster than other, plus visible in IR vapor and exhaust, etc. Just look on youtube for FLIR videos for what it should look like.

[bradmick]

Howdy!

 

Interesting thread. My first thoughts are, please, please, please don't reference that goofy movie Firebirds, heheh. That movie is an embarassment to all Apache pilots (particularly the eye dominance thing...it's pretty bogus in real life) ;) lol. My dad was actually there when they filmed the movie, the real pilots hated it. But, enough on that.

 

My limited experience in the Apache (tuesday was my very first flight) and experience with the IHADDS in the sim and the actual aircraft honestly lead me to think that the way most sims have done the IHADDS picture is probably the best way. Why do I say this? The main reason is that it'd be really, really complicated to simulate a two eye deal on screen. When you're flying days all you have in the lens is symbology, you don't fly with the PNVS or TADS screen so you look out and see the normal world, you're left eye is clear to see the MPDs and whatever else. Now, when its dark, you'd have one eye looking out normal, and a big green blob on the other. It'd be pretty disconcerting for the player i'd say to have this big disconnect in looking outside. In the sight, you don't see any of the cockpit because you're looking through a turret thats about a foot or so in front of you, while your other eye is free to look inside at the MPD pages. Pretty crazy overall.

 

Now, I suppose what could be done is this, and this is the complicated part. What would need to be done is have the HDU modeled and placed at about the point where the 'players' right eye is. The Combiner lens would be situated at the proper spot and have all the symbology displayed there. It'd only be inside the combiner lens, so the player is free to look outside with the 'good eye' and get his symbology data with the other. This would again be a little disconcerting when you go to nights, because you're 'left' eye would be able to look inside the cockpit, so if you looked down and left, you see inside on one part of the screen and see outside on the right side. I dunno how well that would translate though. Not to say it can't be done, but very disconcerting and maybe a little to much.

 

Brad

[Weta43]

Yet why is it black&white ?

 

I'm pretty sure it's been said that it's not - that it's green ...

Also - have a look around 2':50" in the video project 50 ( or in the edge, but it's more washed out in that - that movie has a few colour balance changes - have a look around 1':50" - the Ka-50 is quite blue there)

[Sundowner.pl]

Brad thanks for getting through this material and commenting. I agree with the representation of IHADSS being ok in sims during day operations, well everything th that would be needed is just stick to the HDU resolution, and make it a bit transparent. Yet I'm concentrating here on the night missions, so this need a lot work to do.

 

BTW about that left eye dominance thing, and Fire Birds movie, actually my close friend is right handed, but left eye dominant, and he have a hard time shooting any weapon, just can't concentrate on it. But what's interesting, I don't know anyone else who have that kind of problem, so must be less than 1% of population.