TEXTURE_SIZE_EXP 9 or 10 ?

[Rogen 1,095]

So I've seen this [TERRAIN] section option TEXTURE_SIZE_EXP=10 for some time and have read the setting will improve the LOD radius (via increasing the ground texture resolution x4) for everything apart from PhotoReal according to LM on their forum.

I did give it a go back when I had a lowly 1070 Ti GFX card, however with only 8 GB or ram the card would run out of available memory and thus the frame rate would died a sudden death, nor was the card's internal mem transfer rate high enough to transfer around such large textures, so I put it aside in my mind and left it at that.

First a few snips of info from the LM website to better understand the function and how it works, please refrence the links for the full threads as there is quite a bit of further relevant info for reading.

http://www.prepared3d.com/forum/viewtopic.php?p=172350&sid=58c7154c59fea6ee8f4ce3013d3d9bf7#p172350

Beau Hollis » Mon Dec 18, 2017 2:15 pm

If High Resolution Terrain Textures is not checked: (default)
Each terrain tile has a 256x256 texture generated. The texture exponent is 8 and cannot be changed.

If "High Resolution Terrain Textures" is checked:
Each terrain tile has a 512x512 texture generated. The texture exponent is 9 and can be set to 10 using a cfg tweak)
This requires 4x the terrain texture memory and loading work as the default resolution setting.

If TEXTURE_SIZE_EXP=10 and "High Resolution Terrain Textures" is checked:
Each terrain tile has a 1024x1024 texture generated. This requires 16x the terrain texture memory and loading work. The load time and GPU memory requirements at this level are extreme and only a very small subset of GPUs can handle it today. We opted not to make available via the UI. We left the exponent tweak in so that power users could override the exponent used for "High Resolution" mode, while still being able to disable it via the UI.
 

https://www.prepar3d.com/forum/viewtopic.php?p=166316&sid=a3a231e10c898e4019e88048d2ff680b#p166316

Beau Hollis » Thu Sep 07, 2017 11:54 am

There is a known limitation of this setting currently, which is that photo-real (PR) textures are not improved because the PR source textures are at a fixed resolution and are already assigned to a specific LOD when they are build into the scenery.

 

The snip above about the Photo-Real not being improved kind of put myself off using it as it felt like a half measure and in anycase not having enough memory meant I couldn't perform any valid testing anyway.

Enter the new series 3000 GFX cards with their larger installed memory bases and huge internal mem transfer rates means such use may now be a viable option, and now that I do actually have a 3080Ti with 12 GB of memory I though would give it a trial again.

 

So does setting TEXTURE_SIZE_EXP to 10 make a difference ?

Indeed it does, where for starters graphics card mem use typicaly doubles in any given situation and I've been able to fly in situations where practically all of my 12 GB of ram has been utilised.

As for sharpness, yes that too is improved, and there is a lot less terrain texture popping, as in a lot less of those blurry triangles of ground textures that don't pop into sharpness until you're practically over top of them.

Although I didn't notice much difference to general ground textures themselves where non-photo-real was in use, photo-real did benefit greatly which I was surprised about given LM's statement.

For myself it's a thumbs up, I get improved ground textures and more use out of my GFX card, and do note a restart of P3D is required when changing the setting.

I wouldn't try it if I didn't have a 3080Ti at least, additionally I'm running P3D v4.5 with DX11, so v5.3 users may have a different experience with v5's DX12 implementation.

My conclusion is using the setting of 10 was entirely impractical prior to the release of these advanced GFX cards, unless you had a Titan or something else very high end, but has certainly proved a useful setting now that these advaced GFX cards are more mainstream.

Cheers

Pic of very high memory utilisation:

 

Pic of TEXTURE_SIZE_EXP=9

 

Pic of TEXTURE_SIZE_EXP=10, check the background mountain details. The comparision was created by taking the first pic at 9 and saving the scenario, shutting the sim down and swapping to 10, restarting and loading the same scenario point.

 

General flying using PR with the 10 setting.

 

Edited February 10, 2023 by Rogen

[newtie 540]

Hey Rogen-

Interesting post. I tried to find Rob Ainscough's post on this a ways back but after he left, his posts went with him. But, you have assembled from LM pretty much what Rob explained.

I too have a 3080ti w/12GB so I think I might give this a try. I'm on V5 though but I suspect that shouldn't be a big deal.

Any particular reason your using V4? I still have it loaded on a separate drive as there are lots of great aircraft out there that weren't updated for V5.

[Rogen 1,095]

It's a pro vs. con thing and there were more cons to v5 and more pros to v4.

I do have it installed though for various testing, and I do like some of the lighting improvements but not much else and I've found it's more trouble than it's worth with what it breaks.

I'm hoping v6 is a significant advance on v5, wait and see I guess.

Cheers

[CO2Neutral 278]

That setting will provide you with 1024 

5 hours ago, Rogen said:

https://www.prepar3d.com/forum/viewtopic.php?p=166316&sid=a3a231e10c898e4019e88048d2ff680b#p166316

Beau Hollis » Thu Sep 07, 2017 11:54 am

There is a known limitation of this setting currently, which is that photo-real (PR) textures are not improved because the PR source textures are at a fixed resolution and are already assigned to a specific LOD when they are build into the scenery.

That's a link from 2017.  TEXTURE_SIZE_EXP=10 works on both PhotoReal and Landclass in V5.x

Per LM: 

Quote

The distance at which you get the full 1mpp terrain textures is doubled using 512 textures, and quadrupled using 1024 textures.

This is one reason why I use P3D much more than other simulator platforms as those other platforms can't achieve this level of LoDRadius texture detail and seem very blurry to me.  Yes, it doesn't consume more VRAM but I haven't notice any difference in FPS.

[Rogen 1,095]

14 hours ago, CO2Neutral said:

TEXTURE_SIZE_EXP=10 works on both PhotoReal and Landclass in V5.x

And in v4.5.14 too by the looks of it (the final version release of v4.5).

Cheers

[newtie 540]

20 hours ago, Rogen said:

It's a pro vs. con thing and there were more cons to v5 and more pros to v4.

I do have it installed though for various testing, and I do like some of the lighting improvements but not much else and I've found it's more trouble than it's worth with what it breaks.

I'm hoping v6 is a significant advance on v5, wait and see I guess.

Cheers

I'm in one of those 'breakage' moments right now.
Soon as I get that behind me I'm going to try the 1024 texture expression in both V4 and V5 and see what's what. I've tried for what seems like forever to get ORBX textures to stop that annoying texture filling, like it loads a slightly higher res overlay on top of another, often right out the window. I have plenty of horsepower both CPU and GPU so that was sidelined as a cause a good while back. Looking forward to it.

[Bob Scott 7,743]

One thing that should be mentioned is that use of TEXTURE_SIZE_EXP=10 will noticeably increase your loading time at initial startup.  Once you're flying, there's no real issue due to P3D's fairly effective lookahead scenery caching.  Use of super-fast SSDs doesn't really speed things up, as the holdup is the CPU doing fusion of the mesh, textures, and vector scenery over a much larger area.

[Rogen 1,095]

10 minutes ago, Bob Scott said:

One thing that should be mentioned is that use of TEXTURE_SIZE_EXP=10 will noticeably increase your loading time at initial startup.

Great additional comment to expand the thread reference.

I couldn't really say loading time increasing was really noticable to any degree myself, but I suppose if I timed it.

And yeah the CPU is doing lots of work but does feel pretty good loading overall.

Cheers

[psolk 3,053]

Great info!  Thank you for sharing! 

[cowpatz 243]

Am I missing something? I can't really see any difference in the 2 comparative screenshots.

[chapstick 2,762]

Couldn't tell a difference (landclass) when I tried it but it made loading times much worse. 

[newtie 540]

I tried this with stock ORBX Global base and landclass this afternoon; it's definitely clearer and loading was about a minute. The spotty texture fill was about the same. I'm going to test further with some AM changes.

[Kalnon 160]

I never knew about this setting, and I have 16 GB VRAM to use.

[newtie 540]

Lucky you. 😀

[Kalnon 160]

Yeah I just got it about 4 months ago, I have a 6900 XT and I thank god for it every day since I got it.  I upgraded from my old 5700 XT.  The 6900 XT not only has twice the VRAM but it's also almost twice as fast overall in benchmarks I've seen. I tried it with X-Plane 11 and it uses almost about all of the VRAM at around 15.6 GB when loading a flight in a True Sky HD area but it feels very, very smooth.

Edited February 13, 2023 by Kalnon