[84204] High "Foliage Density" values cause poor performance

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asj5547

Well-known member
When DX11 beta was released I decided to evaluate it, I removed my RTX4080 video card from my PC, so the testing was done with just the Intel 13th gen I7-13700 CPU and integral IGPU, yes the new DX11 beta works good, apart from the already posted issues in the forum, frame rates with the IGPU were acceptable, (about 200-250 FPS) airplanes and helicopters performed good, so after 10 days of testing I decided to reinstall the RTX4080 video card but first I would test the IGPU's frame rate (with every setting at absolute maximum) and compare it to the RTX4080, the IGPU displayed about 10-30 FPS, so I was expecting an increase in FPS with the dedicated card installed, but it was only returning 25-50 FPS, (not what I expected), so I went through the settings list adjusting the settings from highest to low or from yes to no, I found that if the "Foliage Density" is set to 100% it severely reduces the frame rates. (IGPU or RTX4080).

Is anybody else experiencing this concern?

Attached is a picture of the system running with the RTX4080, I7-13700 and 64gb's ram, the airplane is E-Flite Apprentice S 15e, airport is Castle. Foliage 100%, fps 25.

This post is not me criticizing the DX11 beta, in fact the development team have done a great job to get the beta ready in such a short time and it will make a lot of users happy, overhaul I was impressed with the simulator's performance using the IGPU. (With suitable settings applied).Foliage Density 100%.jpg
 
Thanks for the notes (and kind words 🙂)! I can shed some light.

In our internal testing, while we saw some relatively minor variation where one version was a little better or worse than the other, most of the time performance was roughly on par between the DX11 and DX9 versions of Evo.

We are, of course, curious to see if that holds true for a larger set of hardware and software configurations.

The one known exception was the Foliage Density setting. At its default value of 5%, performance was still commensurate between the versions. But as that setting increased, we found that it began to have a very negative effect on performance in DX11 in a way that did not happen in DX9. In some test cases, with Foliage Density maxed at 100% we saw drops to less than 10% of the DX9 framerate (e.g., 470 down to 38).

We did not view this as an obstacle to releasing the beta. We thought most users probably never touch that setting and would never have any problems, but we also wanted to see if we were wrong! And in the latter case, we wanted to see if it was as bad on other systems as what we saw. It sounds like for you it definitely is.

Out of curiosity, did you normally run DX9 Evo at 100% foliage density, or did you encounter this due to playing around with settings as part of exercising the beta?

I will update this thread title with the relevant case number from our issue tracking system (84204), and to further clarify the root cause.
 
Thanks for the reply Ryan Douglas, yes, I did test/compare the 100% Foliage Density with the DX9 version, RF Evolution Public beta, selected 3d Castle airport and with the airplane sitting on the runway I get 320 fps, model in the air and no trees in view I see 440 fps, pass close to a tree and obviously the frame rates drop accordingly, (computing foliage).
Photofields are not affected, (non 3D) the frame rates at Eli Field are, 1,900 with the model on the runway and 2,400 fps in the air. (DX9 and DX11)
To be honest I can hardly see any real difference between 5% and 100% Foliage Density, just that I have built a high-end PC and if there is the option to pick high or low quality, I pick the high, it works in DX9 but not DX11.
The other option I do not use is the Post Processing, Depth of Field, that makes close up objects blurry.
 
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Yep, that totally makes sense. We hope to improve that aspect at some point, but we are treating it as lower priority than a lot of other items because setting the value back to default restores DX9-equivalent performance and because it provides a relatively minor benefit when increased (so people probably won't really miss it). It basically causes the billboard (2D) versions of the more distant trees in an airport to render farther out. For example, at Flight School you will see them on the hills all the way across the valley.

Depth of Field pays attention to where the camera is currently focused, and blurs things in the foreground and background relative to that point. Our eyes do the same thing in the real world. If you pay attention to it, you can use it to help gauge distance in the sim, since objects near the model will be in focus just like it. But unlike the real world, where your eyes are free to wander all over your surroundings at will and are very quick to adjust focus as you do, the sim can't track your actual eyeballs (yet! 😆) and make those adjustments in real time if you go from, say, looking at your airplane to looking at a windsock in the distance or a fence up close. It's also a relatively expensive effect graphically because of how it works.

We fully expect most people to keep DoF off, or at a low setting if anything. It does make for some nice screenshots, though! They look more like the real-world photographs you'd see in a magazine.
 
We have yet to do a side-by-side comparison to see if it matches DirectX 9 performance, but as of version 10.00.073 this is dramatically improved and should be usable. Please let us know your results!
 
Major improvement, difference between 5% - 100% foliage density is less than 30 fps loss. (before update 150 fps loss).
 
Just tried 10.00.073 with my 4070Ti -
In DX9, with the Yak 54 on the runway at RealFlight Ranch, all Quality maxed out, no V-synch, got 142 fps, which only varied a few decimal points in flight. In DX11, also got 142 fps, also very solid in flight. Foliage density made almost no difference whether 0 or 100.

Did however In BOTH versions, get a lot of "flickering" of trees in the distance, and with foliage at 0, on some leaves on close-in trees. Same things flicker at any foliage setting, if they get drawn in both versions. Odd I didn't notice that before....tried turning on V-synch, and no change to flicker, but it did hammer the frame rate - 60 fps in both versions.
 
The development team are making many improvements to the DX11 beta from the received reports by members, you should post your findings on the flickering trees and the development team will probably note it, give it a case number and report back.

Here is another tree issue.

[84394] Some parts of trees have a strange appearance, float in air, with high Depth of Field and manual zoom levels

Airport: Palace DoF: 100 Manual zoom: Medium to High Pictures - Far: looks particles floating around dues to low density vs the rest of the tree - Close 1: orphaned low density foliage - Close 2: orphaned high density foliage
forums.realflight.com
 
asj5547 said:
The development team are making many improvements to the DX11 beta from the received reports by members, you should post your findings on the flickering trees and the development team will probably note it, give it a case number and report back.

Here is another tree issue.

[84394] Some parts of trees have a strange appearance, float in air, with high Depth of Field and manual zoom levels

Airport: Palace DoF: 100 Manual zoom: Medium to High Pictures - Far: looks particles floating around dues to low density vs the rest of the tree - Close 1: orphaned low density foliage - Close 2: orphaned high density foliage
forums.realflight.com
Click to expand...
Guess I just fly, and don't observe the scenery much. Ran the same settings in RF 8, and the flickering trees were there too! Or maybe it is the new video card, vs the old 960 .....
 
@Flapper Hello, if you want we can compare with our devices if you make a short screen recording and put it somewhere sharing the link here.
 
Will do later today. Would have earlier, but good ol Windows gave me fits when trying to use the Snipping Tool for a short clip. So had to go down the rabbit hole for fixing that....
 
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