Stupid question about the terrain textures...

[Daube]

Hi all,

This question is aimed at those who know how the terrain texture are handled in the sim. I just saw a topic on the FS9 forum which made me wonder about something...

As we all know, terrain tiles that are close to our position are displayed in high resolution, quite crisp.
And terrain tiles which are far away from us are displayed in a very poor resolution, quite blurry but too far to notice.
And when we move closer to a certain tile, FSX replace its low-resolution texture by a higher resolution one.
And when FSX cannot do that in time (because of bad tweaking or lack of CPU power), we get low resolution textures next to us, producing the famous "blurries".

Now, is that linked to mip-mapping somehow ?
MipMapping can be implemented in two ways:
- all of the texture resolutions into one single texture file.
- several texture files, with different names, each with its own resolution.

*IF* this is the case, then what happens if:
- we remove the lower mips from a terrain textures, as we do for plane textures sometimes ?
- we replace the low resolution textures by high resolution textures with the same name ?

Is that even possible ?
Sorry, this may be dumb, but I had to ask...

[Paul Anderson]

You could try combinations of lod_radius (I use 6.5) and texture_max_load (I use 2048 or 4096 depending, 4096 doesn't seem to hurt if textures less than that).
Assume you tried the usual tweaks with
TEXTURE_BANDWIDTH_MULT (I use 70) and

IMAGE_QUALITY (I use 3)

Hope this helps.

[Meshman]

Well, why don't you give it a try and let everyone know how it works?

I *think* Imagetool will work in a batch mode. If so, you'll need to run through all the files in \Scenery\World\texture. Once they are converted to plain 1024x1024 files you can fire FSX up and ... hope for the best! I'm taking an educated guess that the sim should run for a short time before you get a BSOD. That's if it doesn't crash before the loading bar gets to 100%?

Doesn't it make sense that a system struggling with drawing textures to their sharpest level in a small radius around the user's aircraft is going to have a problem if you try and cram it full of sharpest textures? I'm guessing because the game is set to function in a particular manner, when it encounters something beyond that it may "struggle" or turn into a nice slide show.

Be sure and make a complete backup of the \S\W\texture folder before starting.

[BASys]

Hi Folks

Stopping unnescessary applications & services should be your first port of call.

Adjusting FSX sliders next.



Replacing lower MIPs with higher-res versions
would not work
and would only quicken the onset of the blurries
as you'd have utilised/squandered your PC's previously available resources.



Removing lower MIPs entirely
would be an extreme/ultimate and not recommended last resort.
as whether on aircraft or scenery, (AIUI),
it'd only work to a limited extent.



Whatever -
Whenever your PC's currently available resources are fully utilised,
FSX then will fallback to dithering everything in the viewport.

A good indicator of this occuring
is the menu text starts to become blurred.



HTH
ATB
Paul

[Daube]

I would try these things unfortunately imagetools is not installed on my PC and I have no knowledge on how to use it.
Concerning the various tweaks, I am well aware on how to use them, and I am also well aware of their limitations.

Concerning the remarks made by BASys above, of course the removal of the mips would have quite an impact on the system, however I wonder how much this impact would be. I mean, the textures in high res are already loaded in memory anyway, and on generic sceneries with normal landclasses, there are not hundreds of textures to show, the same ones are repeated again and again. This would be different on photoscenery, yes, that's a fact. But still, I would be curious to see exactely how much video memory would really be used, on recent hardware.

Sure the removal of low mip levels from the textures is an extremist approach, but this is precisely the point: since FSX is not able to use these mips efficiently enough, let's try to force it to use the high res textures instead of multi-mip levels. IF the menus get blurred, well then we will get to know the limits.

[Paul Anderson]

I tried the mipbias=6 (or 7) tweak before.
Looked better but ran slower.

[scott967b]

i think you may have a problem in that FSX actually creates synthetic terrain textures using a software 2d rasterizer, Anti-Grain Geometry. I'm not sure removing mips from the source images is going to achieve much, but I guess it never hurts to try.

scott s.
.