A request for improvement of incorrect, dynamic in-cockpit reflections.

Hello there.

In the Patch Notes Discussion Thread, NineLine asked me to post some screens of 2.5.xx in-cockpit reflections issue I'm not happy with. Not wanting to clog that thread with more off-topic stuff, I'll start a separate one.

The issue is deferred-shading related and has been with us since introduction of this technique.

In short - with the way the rendering of dynamic terrain reflections onto the airframe is implemented now, the reflections are emited "through" the structure and "into" the cockpit from below, even at level flight, as if the cockpit had no floor, or the floor was made of glass ;). As a result, when flying low above dark forest - the cokpit gets the dark green tint all around, over light green fields - light green tint is present. Over the sand the pit turns yellow, over the runway concrete it turns grey, over the water turns blue etc. Fly level, low above the map with multiple terrain features and your cockpit becomes a disco club. Three Spitfire screenies below highlight the effect, all taken within a minute, flying over the surfaces of different colours in the same direction. Apart from the general colour tone of the green paint, note the gauges, the radio box and wobble pump handle, as examples where the effect is most apparent. Static screens are not perfect, a video would be a much better showcase, but you can fly low above any non-uniform terrain in Caucasus or Normandy, clear mid day conditions and observe the effect yourself.

This is not how light propagation works in real life, as in the aircraft with perspex canopy on top the only light sources in the pit are sky with everything on it (direct source), pilot's upper body and adjacent/opposite stuctural elements and panels (non-direct/reflection sources).

Mind you, the effect we see in game would be plausible (though overdone somewhat) if we flew high-wing monoplanes like Cessna, in which the bottom surface of the wing, usually painted white, becomes a big, additional source, reflecting light from anything below directly into the pit windows. That shouldn't be the case, however, in low- and mid-wing monoplanes we fly in DCS. One could also argue, that the effect might also appear on the ground, when nose-high attitude of WWII taildragger makes part of the outside terrain scenery reflect light into the pit from the aft direction. It should disappear, though, when the plane is already level in the air. There simply can be not terrain reflections going into the pit if there's literally no objects for them to reflect from. Screens show the Spit, other planes are a bit less affected, probably depending on current state of their cockpit texture rework.

I can turn the blind eye on another issue of low "refresh rate" of the dynamic reflections all around (they're rendered with a couple of seconds delay to save precious CPU cycles I presume), but it's difficult to accept their presence on parts of the airframe where they shouldn't exist in the first place.

Especially when they "combine" with secondary gfx problems. Mustang windscreen is an unfortunate example - it suffers from static, pre-baked cockpit reflection layer on perspex texture, which, although present in numerous other DCS modules as well, are much more visible on the P-51D. When additionally lit up from below by aforementioned "reflections-out-of-nowhere", they make spotting contacts on the ground more challenging than needed. Pre-baked reflections are another problem however, already touched upon in numerous threads.

The "disco cockpit issue" was most troubling in 2.2 and go dialed down somewhat in 2.5, but it's still there. Whether it's the result of deferred rendering code limitations, or intended, but greatly overdone eyecandy effect, I wouldn't mind seeing something done with it, as it's neither realistic in it's current shape, nor useful from gameplay point of view.

Cheers.

Unfortunately, in a computer sim where a canopy is not an actual physical layer (as opposed to a Level D sim where you are actually in a cockpit with a physical windscreen), our eyes can't focus beyond the Perspex. In real life, our eyes' / brain wouldn't render such reflections in such sharp relief unless you actually looked at them. Focusing on the ground or on a bandit would make such reflections far less noticeable. We'd only see passing colors and shades.

@ NL - Yes, pretty much, thanks. Though it looks a bit less troublesome on your vid, recorded during romantic sunset, with cockpit in deep shadows (while we're at it what's with you ED top brass people recording most of your vids in low sun hours anyway? Can't troubleshoot colour issues of your software when nobody there flies at noon ;) :D).

In midday hours, brighter, more vibrant colour palette would make the "disco" much more apparent, not to mention flying at noon over most contrasting landscape parts of Nevada map (any sand-water transitions) but you get the picture.

Note that in your vid even when you're over water and roll towards the beach, so one might potentially expect green/yellow'ish land reflections (if any) to be projected into the cockpit from the left, the cockpit still gets lots of the blue tint "treatment" off the water on the right. I'm sure if you paused your flight in that second and switched to external camera, the bottom of the Spit would have the blue reflection, and rightfully so. My gripe is, though, the gfx engine applies this bottom reflection into the cockpit as well, and THAT doesn't make any sense whatsoever.

Now, I understand coding a full, dynamic reflection renderer which takes all angles into account real-time is a chore and such thing would murder our CPUs and GPUs anyway, but I wonder if calculating reflections which should not quite be there really isn't unnecessary resource drag as well?

@ Emmy - You're absolutely right about eye focus factor in real life. I'd suggest, however, simple solution of this software limitation... getting rid of baked reflection layer altogether :D, or at least toning it down (funny thing is, it seems to be more visible on some DCS modules, less on the other, and nonexistent on the rest). It's a cool looking gimmick at first, and gives illusion of sitting under a perspex allright, but when it starts reducing realism one has to ask if it's worth it.

I really hope that this gets looked into in more detail, I think this might also be connected to the sudden changes of lighting on the ground textures too, dependant on your altitude. I tried to explain that in this post before finding this one and this one.

Since 2.5, flying in DCS is not as immersive as it has been previously, as you're being distracted by unexpected and unnatural changes of light, shadow and colour that were not there before the switch to 2.5.

This is a relevant topic IMO, surprised there haven't been more replies. One more thing to add is the reflections are not animated in a smooth way (see the video posted above): the cockpit goes from one color to the other instantly, like the frame rate of the reflection was something like 1 or 2 frames every few seconds. This is very noticeable.

Here's a video showing the sudden light changes....

The light being reflected from the ground into the cockpit seems to be quantized hence the noticeable discrete steps in strength. Also there is a delay - even after you've crossed a coastline and are over the water the cockpit is still 'glowing' yellow from the field you just left behind. Lastly the effect is much too strong.

On reflections in DCS I'll just repeat my view from the previous thread -

Until we have the horsepower to model reflections properly we are stuck with painting textures on canopies.

And as long as we are stuck with painting textures on canopies we need to dial them back to almost invisibility because otherwise any illusion you were attempting falls apart immediately.

You can just about get away faking the reflections of objects very close to the canopy with something subtle like this.....

But this....

Yikes.

One solution would be adopting the technique used on the MiG-21. The canopy is textured with an amazingly subtle but effective 'dust' layer that catches the light beautifully but never looks fake. Of all the DCS modules it's the only one, in my opinion, that convinces me I'm looking through something at the outside world.

I hope something like that can be adopted for future modules (and refitted to the older ones!).