Author Topic: P3DV5 Dynamic Lighting  (Read 3469 times)

atco

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P3DV5 Dynamic Lighting
« on: April 18, 2020, 12:25:46 am »
Umberto, if I may I would like to ask about dynamic lighting you use in P3DV5.

The reason I ask is I am running a 4K monitor and I'm getting crippling performance at addon airports at night using DL - but not at FSDT airports.

It's well known that in V4 you had to run Anti Aliasing at 2xMSAA at most to use dynamic lighting on a 4K monitor. If you go above that you would get a slideshow. At 2xMSAA though its perfectly possible to run V4 with full dynamic lighting at 4K with almost zero performance hit.

Now I've found in V5 that even at 2xMSAA my FPS drops at least half when the lights come on. Performance during daylight is fantastic.
Here are the numbers at a handful of addon airports:
Day 44
Night 13

Day 52
Night 26

Day 57
Night 27

Yet at KCLT and KSDF of yours there was absolutely zero difference.

Now all the above addon airports are offical V5 airports installed with native V5 installers. Even turning AA off completely resulted in only marginal FPS improvements so I'm doubting that this time AA is the cause of the problems.

The only possible clue I can think is that each of the addon airports uses .fx effects files for dynamic lighting. And I am wondering do you use .fx files as well or do you inject your DL into the scenery using couatl? Could that possibly be why I am seeing this?
I know that LM have made changes to how fx files interact with the sim, particularly landing lights for aircraft and how they interact with PBR. There are some new variables. The only reason I can think why the other airports DL is such a slideshow and yours is not is that either you have created fully V5 SDK compliant fx files or you bypass them completely.

Have any other users running 4K resolution found similar performance hits using Dynamic Lighting in V5?

virtuali

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Re: P3DV5 Dynamic Lighting
« Reply #1 on: April 20, 2020, 01:46:35 pm »
And I am wondering do you use .fx files as well or do you inject your DL into the scenery using couatl?

Yes, we updated all our sceneries that use PBR ( non-PBR scenery don't require that ) to use V5-specific .FX files.

And yes, Couatl has everything to do with the fact you see almost ZERO impact of DL in our airports, compared to every other developers airports, that don't have much control over how DL lights are created. While almost everybody just places all the DL in a .BGL, hoping for the best, we have a fairly complex "hybrid" method, which works this way:

- The .BGL contains a few basic DL lights, not not have the scenery be entirely pitch black at night, and these are made in the traditional way, and are always on.

- When you approach close to gates, we use what we call the "collision system", which is a system provided by Couatl ( runs in the background, with zero effect on fps ), so we can trigger things to appear only when the airplane is inside a specific area, not just a rectangle or a radius, but a polygon with a precise shape, nothing you see on screen, it's a logical polygon.

This way, we create/destroy additional  DL lights, which are the ones with the biggest impact on fps because, instead of having 150-200 DL all visible at the same time, which would be the case if we used just the .BGL format, we only have the generic ones + the one on the terminal closest to you, even the right side so, typically, we don't have more than 6-7 DL lights in addition to the generic ones, so the overall count of lights in the scenery is always way lower than any other comparable scenery.

We use this kind of optimization for lots of things, like visible passengers inside terminals ( KORD and LFSB ), or the active Gate Panels ( KORD ), and for some of the ground traffic too ( KMEM, KSDF, KCLT ). The DL optimization is used for all our sceneries that comes with DL, so all of them from KCLT onward.