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Mike_CFII_MEL

Alpha Channels - MIPS - DXT1/DXT3

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Hi Everyone,

 

I've been doing some reading in regards to Alpha Channels, MIP Maps and non DXT3/DXT1 files. I've been looking into the possible problems associated with the use of non DXT3/DXT1 format and the lack of an Alpha channel, such as FPS Loss and/or studders and the ability to reduce and/or eliminate these problems by converting them (Image Tool and DXTBmp) to dxt3/dxt1 and adding an alpha channel.

 

Anyone venture into this with P3D?, if so can you report on an approximate time frame (I know the time frame will vary depending on installed items) required to take on a task such as this, programs used to convert the offending files (such as Image Tool, DXTBMP), any batch programs / edits / automated programs used for the conversion, and final results.

 

 

Thanks

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Michael,

 

There's a thread going on about just this in the FS9(2004), forum. I've done the alpha channel and mip maps today in my FSX, and, well not sure at this point whether I gained anything. Need to do more testing. Took me about 5hrs, but as you said it depends on how much scenery you have installed.

It's really easy to do, just time consuming.

 

 

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

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. I've been looking into the possible problems associated with the use of non DXT3/DXT1

What problems are you referring to? Personally, I'm not interested in fixing something that isn't broken or at the very least, break it more. There are good reason why they are there. Now Fs2004 I have no idea. but I would be hesitant about applying theses to FSX or P3D. I can recall this going on yrs ago. Converting all texture dds to DXT1 or something like that. It was suppose to increase performance but turned out, It wasn't wise!

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Hi,

 

I wonder if the results (seen by some) for FS2004 will benefit P3D users such as myself. Looks like I have some additional reading ahead of me.

 

 

Michael,

 

There's a thread going on about just this in the FS9(2004), forum. I've done the alpha channel and mip maps today in my FSX, and, well not sure at this point whether I gained anything. Need to do more testing. Took me about 5hrs, but as you said it depends on how much scenery you have installed.

It's really easy to do, just time consuming.

 

 

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

 

Hi,

 

I believe the associated problems were stated in my first post. However, here they are again "such as FPS Loss and/or studders"

 

What problems are you referring to? Personally, I'm not interested in fixing something that isn't broken or at the very least, break it more.

 

Hi,

 

All textures should "NEVER BE DONE"!. Someone correct me if I'm wrong, but I also believe that DX1 does not support or allow an ALPHA channel, so I'd rather convert to DXT3 with an Alpha channel. DXT1 would be nice to use for creating MIPs but you lose the Alpha channel, looks like its going to be a long slow process.

 

Converting all texture dds to DXT1 or something like that. It was suppose to increase performance but turned out, It wasn't wise!

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I've just completed a short flight, nothing heavy ie no NGX. FPS seemed more consistent and the textures seemed more 'crisp'. Now not sure if that was just my wishful thinking, mind!

 

Please remember I'm using FSX!

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Hi,

 

Thanks for the info and possible FSX results.

 

I've just completed a short flight, nothing heavy ie no NGX. FPS seemed more consistent and the textures seemed more 'crisp'. Now not sure if that was just my wishful thinking, mind!

 

Please remember I'm using FSX!

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Hi,

 

Looks like a few individuals are going to make this type of conversion easier by giving us the ability to batch convert the problem files, this is what I've been able to take away from everything I've read.

 

1. Run AlphaSearch2: To identify if you have any problem files.

2. Run convimx to batch convert the files to DXT3 with MIP Mapping.

3. Run DXT3_fixer to batch fix any files that do not have and/or have lost their Alpha Channel.

 

I am aware of the danger of batch conversions/fixes, as well as the benefits. I'll have a complete backup of all files prior to trying this and would suggest anyone who is going to try this do the same.

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Hi,

 

Mipp/Alpha conversion is complete, now begins the testing...

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Well, I can now say that there is an improvement in FSX, not with increased FPS but, the FPS is steadier , no shimmering and no 'blurries' during a flight; so far!

 

the test will be with the NGX.

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I have just recently installed FSX with only a few freeware addon sceneries.

I thought that FSX only used dds and dxt5 compressed bitmaps, but my tool DXT3Fixer found a bunch of dxt3 without alpha channels. Barbados (TBPB) from the filelibrary here at avsim is one example.

The fool fixed all the files and there are no more stutters at Barbados ^_^

 

What I don't know yet is if dxt5 without alpha also causes stutters. If so, I could update the tool to fix alpha problems for dxt5 as well.

Have to do some testing...

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this is getting very interesting :rolleyes:

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It certainly is. Mike and others are convimx and DXT3_fixer downloadable utilities or are they integral to Windows?

 

Like you I have a blind faith that what works for FSX will work for those of us on P3D. I still get stutters and shimmering even with plenty of CPU power and high AA and AF settings, and if this is one way to reduce these then I'll certainly try it.

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Ian, you may find that Ver 1.4 is going to address this issue. Worth waiting until we see it I think.

 

Mac

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Perhaps the original author could post a question on the P3D company forum to see if they have looked at this and what their findings were. Why waste flying time if it is not valuable in P3D or, if it is a good step, it may be in release 1.4 ..

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Hi,

 

Well, the sim seems more responsive and is quicker to load. I do not see any increase in FPS, maybe one or two FPS, but the sim is smoother. Even though P3D was very smooth prior to applying this fix, I still believe it was worth the time to fix these textures.

 

Now back to another flight.

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Great, can you add support for DDS?

 

I have to study the dds file format first, so we'll see.

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I've updated my tool that fixes textures with bad alpha data. It now does dxt3 AND dxt5 files.

 

It's not in the filelibrary yet, but for now you can get it from here: http://www.2shared.c.../DxtFixerX.html

 

 

Fantastic work. Many Thanks

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Hi,

 

Seems, P3D is really stable on my setup now. With 1.4 right around the corner, it can only get better.

 

For me P3D has now become flight simming at its "very best", AFAIC P3D is my choice for flight simulation...

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Great tool, thanks a lot for youir effort.

I tested on FSX and gained smoothness in several sceneries.

Will soon test it with Prepar3D.

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Ok so I fixed all the alphas of the BMPs it found with this new utility. (DXTfixer). Now this do fix the alpha channel.

 

Please help an old man here. Another question seemingly related if I read other posts.

 

What is the story with missing mipmaps.

 

I have read further here and found the alphasearcher. This utility now confrm that I dont have any aplha issues anymore (both DXTfixer and alpha earcher returs zero errors), but Alphasearcher is listing a HUGE number of missing mipmap files.

 

What is the effect of these missing mipmap section from the bmp file. 98% of these files are AI traffic. Would you recon I correct this manually. I dont know what the impact is of a missing mipmap. Sorry I have no idea what a mipmap is and even how to correct that manually.

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This a great thread and tool, any reports on .dds files having the same problem? Or if converting DXT1 to DXT3 with alpha shows any improvement?

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