P3D Dynamic Lighting impressions?

[DrumsArt 270]

20 hours ago, Rob Ainscough said:

For those airports that aren't well optimized with DL, I keep DL enabled in P3D Graphics options, but just disable the airport's specific DL ... that way I can still enjoy the DL from the aircraft and AI aircraft but not take the FPS hit from unoptimized DL capable airports.

Sorry, no more flat triangles for my night flying ground adventures.

Cheers, Rob.

Please, how do you do that?

Thank you and Regards,

[ssair1 92]

Overall, dynamic lighting is a great feature in v4. But I do experience studders, sometimes, just before touching down at high-density airports. 

Regards, 

[Gregg_Seipp 565]

I guess what really bugs me about DL is that only a few lights requires an $800 video card upgrade to get smoothness.  Otherwise, you have to selectively turn the feature off or take odd steps for performance of an aircraft.  Yeah, we all want natural lighting but, unless some performance enhancement can be made, as more and more things are made with the new lights, perhaps when P3D5 out, people will have to upgrade again.  Chunk of change.

[Guest]

3 hours ago, Gregg_Seipp said:

I guess what really bugs me about DL is that only a few lights requires an $800 video card upgrade to get smoothness.

Actually if you do ONE airport beacon light that points parallel to the terrain with a very high distance and large radius it will cause a Titan XP to stutter when using 4K and high levels of SSAA.  So it can just take ONE light to drastically reduce FPS.  But "light" is what defines reality ... a single rotating airport beacon increases the complexity of rendering considerably ... you have to render the object, then render textures, render particle effects, then render the object shadows, then render reflections, then apply HDR, then render the varying density light calculations over the distance/radius the light is defined for, then apply AA ... the single beacon light source has the potential to adjust each and every pixel (in 4K that's over 8 Million pixels per frame) at a variable amount based on the light definition and view angle relative to the light source.  

For the old school flat triangle lights (X,Y axis) this is relatively easy, fixed light value adjusts each pixel over a given area (the triangle) - GPUs can handle this type of pixel adjustment very easily.  For "dynamic lights" this process now has volume (it's not a flat X,Y triangle but a cone of light with volume - X,Y,Z) ... and the intensity of the light "fades" over distance in all three axis of the virtual world (X,Y,Z) so we no longer have a fixed light adjustment value for each pixel (it's now a calculated value based on radius and distance), and because DL is a cone it impacts pixels in X,Y,Z virtual space so many many more pixels are needing adjustments.

Now, the options to improve these light calcs comes by shifting the render pipeline so that light calculations are done in a more optimal phase of render so calculations are less complex, often called deferred rendering ... (this is what XP11 does).  There are some benefits to deferred rendering when it comes to light calculations but there are also some penalties to deferred rendering, specifically shadow calculations.  If you notice XP11 shadows are pretty horrible (most people turn them off). Have you also noticed that XP11 and P3D do NOT render shadows based on the DL source, adding shadow calcs to dynamic lights would bring even a new Titan V to it's knees. 

So the warning here, is be careful for what you wish in P3D V5 and hope there is an option to turn the feature off because any flight sim that "adds" to visual improvement IS going to require more GPU processing power, especially anything that is "light" related.  For night flying only, I recommend:

1.  2XMSAA + FXAA
2.  Turn all Shadow calcs off with the exception of cloud and Internal and External Vehicle (not really going to see those anyway)
3.  Turn Dynamic Reflections off (again at night doesn't add much to the visuals)
4.  Adjust DL settings (if possible) at the airports being used ... you can have a lot of DL lights at large airports, really depends on how the developer sets those lights up

I keep multiple Day/Night graphics settings as it's relatively easy to switch between the two during any flight session.

Cheers, Rob.

   

[Gregg_Seipp 565]

12 minutes ago, Rob Ainscough said:

Actually if you do ONE airport beacon light that points parallel to the terrain with a very high distance and large radius it will cause a Titan XP to stutter when using 4K and high levels of SSAA.

Not going to quote all of that but, the entire thing makes a lot of sense.  I see it in 3D development software...when you render even one object can bring your system to its knees.  Imagine a rotating beacon...constantly changing direction...

Seems like the best we can hope for is a kind of lighting pre-render where it do as much of that work during startup.  On the other hand, simpler things might still pay off.  The 'artificial' night lighting is still steadily improving.  Perhaps we'll see more of that.  

[Mitch24 194]

I don't get why Lockheed Martin can't improve the DL performance, they were the ones who implemented it, so they should fix it!!!!!! They obviously don't know how, or don't care enough to want to fix it. 

[Guest]

2 minutes ago, Mitch24 said:

I don't get why Lockheed Martin can't improve the DL performance

I recommend you read what I wrote above.  Can't fix what isn't broken ... you can however buy better performing GPUs or use the above suggestions to improve the performance of DL.

Cheers, Rob.

[Gregg_Seipp 565]

1 minute ago, Mitch24 said:

I don't get why Lockheed Martin can't improve the DL performance, they were the ones who implemented it, so they should fix it!!!!!! They obviously don't know how, or don't care enough to want to fix it. 

Honestly, for me, as long as they keep a way to turn it off, I'm pretty okay, mostly.  I'll have to see what my PMDG performance is, though.  Rob's suggestion does, indeed, help.  And his point about developers carefully monitoring their performance is important.  They need to be careful.

[ssair1 92]

10 minutes ago, Rob Ainscough said:

I recommend you read what I wrote above.  Can't fix what isn't broken ... you can however buy better performing GPUs or use the above suggestions to improve the performance of DL.

Cheers, Rob.

Any idea what the future roadmap for Prepar3d will be? 

Regards,

[anden145 2,285]

24 minutes ago, Rob Ainscough said:

I recommend you read what I wrote above.  Can't fix what isn't broken ... you can however buy better performing GPUs or use the above suggestions to improve the performance of DL.

Cheers, Rob.

+1 Rob! Hopefully, they can optimize it, though.

12 minutes ago, ssair1 said:

Any idea what the future roadmap for Prepar3d will be? 

Regards,

I hope, some kind of optimization of Dynamic Lighting. Although, I must admit, that I don't struggle with it. I seems to be mainly users, who either use very high resolutions and/or extreme AA/AF settings... 

Also, some kind of overhaul of the weather engine and cloud depiction is (in my opinion) solely needed.

[Romeo_Tango 143]

8 hours ago, DrumsArt said:

Please, how do you do that?

Thank you and Regards,

+1

[mikeymike 357]

On 2017-12-09 at 0:02 PM, Rob Ainscough said:

I love DL ... unfortunately it's performance impact will vary considerably based on the developer of the scenery/airport and how they setup/define their lights.  With DL enabled I operate 2XMSAA and FXAA at 4K and performance is excellent (very very minor FPS hit and not enough to drop below my 30 FPS threshold) as are the visuals (less of a need for AA at higher resolutions like 4K upwards).

A 1080Ti will make a huge difference over 970 when it comes to DL, but again it'll boil down to you AA choice.  Sounds like you might be ready for nVidia Titan V (Volta) ... let us know how it goes if you get one :)

For those airports that aren't well optimized with DL, I keep DL enabled in P3D Graphics options, but just disable the airport's specific DL ... that way I can still enjoy the DL from the aircraft and AI aircraft but not take the FPS hit from unoptimized DL capable airports.

Sorry, no more flat triangles for my night flying ground adventures.

Cheers, Rob.

Just tested that setting of fxaa enabled and 2xmsaa with my

49inch 4K tv

Using my 2 x titans sc first edition 

in sli

wow what a performance gain

was using 8xmsaa prior

but was getting stutters.

all smooth now

thank you 

[him225 51]

Performance drop with DL depends on the quantity and complexity of the illuminated objects, but it is kind of odd for most to presume that they are poorly optimized. It is probably running optimally for what it costs but don't get why LM decided to hold back shadows for them. They could tank most systems yes but that's what the options are for - to disable it if a scenario/system cant take the load like is done for other settings. Another way to optimize a scene would be to limit the number of active or detail of the dynamic lights based on a settable number or frame rate starting by culling those farthest from the viewpoint. There is an entry in p3d cfg to limit max number of DLs but not sure if it works by distance to preserve visual fidelity around the view position.

[Nemo 1,305]

15 minutes ago, him225 said:

... There is an entry in p3d cfg to limit max number of DLs ...

Which entry should this be? I cannot find any.

[AnkH 2,233]

On ‎09‎.‎12‎.‎2017 at 6:02 PM, Rob Ainscough said:

For those airports that aren't well optimized with DL, I keep DL enabled in P3D Graphics options, but just disable the airport's specific DL ...

How can you disable DL specifically for an airport? Via AFD?