P3D v4 TFDi Design TrueGlass


TrueGlass is a rain, icing, and fog effect for aircraft windshields in Prepar3D v4 exclusively. All rain drops are placed dynamically, and react to aircraft speed. Heavy rain will yield more drops and streaks than a light rain, which is quite noticeable when flying in and out of storms with a third party weather engine such as ActiveSky.

This is an entirely separate code base and implementation from the windshield rain effects present in Prepar3D v4.0. The effect must be implemented on a per-aircraft basis.

TrueGlass will be available first for our 717 in the near future. The goal is to work with other aircraft developers and implement TrueGlass into their products. Exact distribution and licensing details are still being worked out internally.

We originally started TrueGlass back in early 2016 in FSX, however the performance impact was too great when utilizing old technologies in that platform. P3D has introduced new technologies that have allowed us to achieve minimal to no performance impact.
 

Heretic

Resource contributor
Would love to hear about the technical intricacies of the system and especially about why exactly it was that performance intensive in FSX.
 
Would love to hear about the technical intricacies of the system and especially about why exactly it was that performance intensive in FSX.
I can't go into too much detail about the current version of the system, however the original FSX testbed utilized the gauge API. Rendering large areas rapidly with a gauge causes significant performance degradation, especially on transparent surfaces.
 
Amazing...Isn't v4.1 supposed to include some kind of windshield rain effect by default? I've heard LM mention the "beginning stages" of rain on glass surfaces, and I'm looking forward to seeing how it works next week when the update rolls in.

Since they don't seem to be bragging about it too much yet though, it probably won't be anything close to this. This is insane... :eek:
 
Amazing...Isn't v4.1 supposed to include some kind of windshield rain effect by default? I've heard LM mention the "beginning stages" of rain on glass surfaces, and I'm looking forward to seeing how it works next week when the update rolls in.

Since they don't seem to be bragging about it too much yet though, it probably won't be anything close to this. This is insane... :eek:
Prepar3D v4 launched with rain effects, but only in one aircraft. You can check the Mooney Bravo G1000 if you're curious what it's like. The mention of rain effects coming in v4.1 was a bit misleading on their part, as they're only adding the existing effect to other planes.
 

JB3DG

Resource contributor
Amazing...Isn't v4.1 supposed to include some kind of windshield rain effect by default? I've heard LM mention the "beginning stages" of rain on glass surfaces, and I'm looking forward to seeing how it works next week when the update rolls in.

Since they don't seem to be bragging about it too much yet though, it probably won't be anything close to this. This is insane... :eek:
Also the default effect is the old animated texture system. TrueGlass is fully dynamic generation of the raindrops and so allows for wipers to have purpose as Hughes-MDflyer4 pointed out.
 
Also the default effect is the old animated texture system. TrueGlass is fully dynamic generation of the raindrops and so allows for wipers to have purpose as Hughes-MDflyer4 pointed out.
I bet a lot of custom DirectX shaders were involved with this too...it looks like the drops are actually refracting the environment the way that actual water does. And even the wiper tip streaks are on point.
 

Heretic

Resource contributor
I can't go into too much detail about the current version of the system, however the original FSX testbed utilized the gauge API. Rendering large areas rapidly with a gauge causes significant performance degradation, especially on transparent surfaces.
Did you try to have a 2D gauge run a whole lot of individual raindrops? No wonder why performance tanked.
 

n4gix

Resource contributor
Also the default effect is the old animated texture system. TrueGlass is fully dynamic generation of the raindrops and so allows for wipers to have purpose as Hughes-MDflyer4 pointed out.
I expressed my disappointment in the P3D developer's forum. I truly expected more out of L-M than simply resurrecting this ancient MSFS 'system'. If a relatively tiny company such as SCS can develop a truly dynamic rain/snow effect with working wipers (that don't simply disable the raindrops for the wiped area) using shaders, then I should think a much larger and better funded company could have done the same...

I'm delighted that the terrific folks at TDFi are cracking this nut so well! :wizard:
 
I bet a lot of custom DirectX shaders were involved with this too...it looks like the drops are actually refracting the environment the way that actual water does. And even the wiper tip streaks are on point.
There actually isn't any refraction, just a trick on the eyes with some creative texture work. :)

Did you try to have a 2D gauge run a whole lot of individual raindrops? No wonder why performance tanked.
It's not like there were any other methods available at the time that allowed the level of functionality we aimed for. Sure there were other ways of doing it, but those methods only allow for very basic stuff and look pretty bad by today's standards. We're randomly placing drops, they will never repeat or look the same.
 
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Heretic

Resource contributor
It's not like there were any other methods available at the time that allowed the level of functionality we aimed for. Sure there were other ways of doing it, but those methods only allow for very basic stuff and look pretty bad by today's standards. We're randomly placing drops, they will never repeat or look the same.
Did you manage to make the drops "wipeable" without any invasive 3D model work in FSX?
I can live with the rather unrefined bitmaps I'm using right now, but I still haven't figured out an efficient way to interact with wipers beyond cutting the wiped area from the glass area used by the rain texture.
 
Did you manage to make the drops "wipeable" without any invasive 3D model work in FSX?
I can live with the rather unrefined bitmaps I'm using right now, but I still haven't figured out an efficient way to interact with wipers beyond cutting the wiped area from the glass area used by the rain texture.
Yes, the wiper wipes away only the areas it has passed through when it starts moving, however once the wiper is moving, no drops will appear in the wipe-able area (not a huge deal since the wipers in most planes move extremely fast.
 
Yes, the wiper wipes away only the areas it has passed through when it starts moving, however once the wiper is moving, no drops will appear in the wipe-able area (not a huge deal since the wipers in most planes move extremely fast.
So is each window its own "gauge" that renders the droplets and runoff at random (or predetermined?) locations, and moves them relative to airspeed based on the angle of airflow to produce the illusion? Or is it actually programmed to behave like a physical system that responds to gravity and airflow vectors?

I don't mean to make you expose any design secrets...but I'm just really curious as to how it works, even though I could never code something to save my life.
 

Heretic

Resource contributor
Yes, the wiper wipes away only the areas it has passed through when it starts moving, however once the wiper is moving, no drops will appear in the wipe-able area (not a huge deal since the wipers in most planes move extremely fast.
Not exactly what I wanted to know, but thanks anyway.
 
So is each window its own "gauge" that renders the droplets and runoff at random (or predetermined?) locations, and moves them relative to airspeed based on the angle of airflow to produce the illusion? Or is it actually programmed to behave like a physical system that responds to gravity and airflow vectors?

I don't mean to make you expose any design secrets...but I'm just really curious as to how it works, even though I could never code something to save my life.
For the sake of explaining the concept, yes - each window essentially has a gauge for its rain. All drops are rendered at random positions for each window (can be mirrored on each side of the cockpit for optimization, but there isn't really a performance hit that we've noticed so far anyway). Movement isn't physically based, it's defined manually (static movement is always top to bottom, in-air/moving behavior is tweak-able per window via a config file).
 
Hi,
As suggested on your website (https://tfdidesign.com/TrueGlass.php - Pricing), I sent a request to obtain TrueGlass as a developer freeware but the automatic answer got me a bit confused.
My question: are you ready to respond to this kind of solicitations or your annoncement was made a little prematurely ?

I was very interested in this developement since at the moment I was carefully studying the SDK of P3D v4.1 (and LUA scripts) to implement this kind of effect on the current planes: Ti'Bush Cessna 150 and CL215T
 
You gotta give us more than 12 hours for something like this - we JUST launched everything. We've had an overwhelming amount of support on this, more than we originally anticipated, so our initial plan had to change to react. You should have received my reply to your ticket just now - the system just gives you an autoreply to let you know we got it.
 

WebSimConnect

Resource contributor
I expressed my disappointment in the P3D developer's forum. I truly expected more out of L-M than simply resurrecting this ancient MSFS 'system'. If a relatively tiny company such as SCS can develop a truly dynamic rain/snow effect with working wipers (that don't simply disable the raindrops for the wiped area) using shaders, then I should think a much larger and better funded company could have done the same...
I'm delighted that the terrific folks at TDFi are cracking this nut so well! :wizard:
The possibility to include the rain drops using shaders on window textures was there since P3D version 2 and it is a part of standard API ! It is a shame that LM did not include rain/snow in the first place leaving the task to 3rd party developers. First thing when FSW was advertised was ... rain drops....

Well done TFDi that finally you addressed that missing and important sim feature !
 
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