I just downloaded this file called DxtFixer for FS9/FSX. It sounds interesting but this is the first time I have heard about this issue.

 

From the Readme:

 

"This tool fixes the stutters in FS9/FSX caused by dxt3 and dxt5 textures without an active alpha channel."

 

"It's perfectly safe to use, as only dxt3 and dxt5 compressed bitmaps will be searched and modified. And they should ALWAYS

have an alpha channel, so you can't do anything to mess up your sim."

 

Does anyone have anymore information about the issue this utility fixes? I is still creating a log file but it looks like it is finding a lot of issues.

 

Edit: It logged 1677 textures - mostly from add on scenery.

 

http://library.avsim...til&DLID=170822

See this thread, tells you all you need to know.

 

http://forum.avsim.n...e-fps-increase/

I would suggest you put your question into this thread, which as lots of the detail about its use and earlier methods of achieving the same result.

 

http://forum.avsim.net/topic/382519-a-huge-fps-increase/

I just used it for my FSX installation and saw really no difference. I think that a slight difference might have occurred but not big enough for me to notice... I already *always* get 30FPS locked so it isn't like I am in for a huge gain lol

I've also run this through my FSX, same as Ben really, there seems to be no vast FPS increase, but what I have noticed is FSX seems smoother and no blurriness during flight and buildings seem much crisper in appearance. There was a lot of errors in my installation. So no harm done it seems by running it. Also no more texture flashing like I had before.

 

Good one IMHO

Same here, no difference. in fact I tried it on a Dx texture on an aircraft in Prepar3D which always ran smooth, and if anything I got more stutters so I reinstalled the original textures. NOT BROKE DONT FIX. No sure how it effects blurries as FSX textures are DDS. Some aircraft and addon airports still use some DXT textures,

Well, one thing for sure is that neither FS9 nor FSX should have dxt3/dxt5 compressed BMP textures with the alpha channel flag set wrong. That causes stuttering.

And so far those files are the only ones DxtFixerX can fix.

DDS is not the same as BMP but the compression method is the same, i.e. dxt1,dxt3 or dxt5.

I don't know yet if DDS files are fine without alpha channels, could be that they are.

Fixes stuttering in FS9 and FSX caused by dxt3 and dxt5 files without active alpha channel data. Read the readme.txt for intructions on how to install and use.

 

I'm confused by this.. If a developer has modeled something in a way the materials don't need an alpha channel (ie: no transparency or shine) and he unwraps it as such.. How would adding one help performance?

I'm confused by this.. If a developer has modeled something in a way the materials don't need an alpha channel (ie: no transparency or shine) and he unwraps it as such.. How would adding one help performance?

 

Because DXT3 and DXT5 textures MUST have the alpha channel present, even if its completely white. Its a requirement of the texture format.

 

The issue occurs when the Alpha flag is wrongly set in the texture, this can happen when Imagetool is used with an all white alpha. When the texture is saved as either DXT3 or DXT5 the alpha flag in the texture is wrongly set as off and this causes significant rendering problems. You absolutely WILL get stutters and performance problems with any DXT3 or DXT5 texture where the Alpha flag is not set to on. This is not particular to Flight sim or its engine, this will happen in any game or any engine.

 

DXT3 and DXT5 should never, ever have the alpha flag set off whether by design or by accident, but unfortunately many sceneries and aircraft and other addons have these problem textures in them.

This issue is not really about achieving an FPS increase, the missing alpha flag causes stuttering, although if you have a significant amount of these textures for example at an addon airport then the stuttering will lead to a choppy and slow performance.

The problem I believe is mostly or all in bmp-formated files, not dds. Both bmp and dds files have headers which provide info about the content of the files. For DXT3 and DXT5 compression, that data includes a "flag" about the alpha channel. (I don't think it is an issue for DXT1, because in DXT1 encoding, alpha data is determined block-by block by reading the data.) What the problem is, is when the alpha channel is set to "white", or opaque (understand on AC diffuse texture alpha normally is reflection not transparency) on every pixel, if the flag should be set to "alpha" or "no alpha".

 

Edit: atco kind of beat me to it. AFAIK, the header format for bmp is not really well specified, compared to DDS where MS has a complete spec for it.

 

scott s.

.

Thanks atco and scott for explaining things, AGAIN

I'm getting a little tired of doing that myself.

Diggin this one out: does anybody know, where I can get this little tool from? It seems to be not any longer in the avsim library... Otherwise I have to do it manually, which is... well... not that pleasant

Diggin this one out: does anybody know, where I can get this little tool from? It seems to be not any longer in the avsim library... Otherwise I have to do it manually, which is... well... not that pleasant

 

https://dl.dropbox.com/u/52676345/Texture_Correction/dxtfixerx.zip

Thank you for sharing it, really appreciate that!

Of course it's still in the avsim library. Just search for "dxtfixerx" and you'll find the download for the latest version (2.1).