Possible FSX autogen performance fix

[Forkboy2 27]

>Try this (there may be a better way, but after some trial and>error, this worked for me):>>after installing the DirectX SDK,>>1. copy the file C:Program FilesMicrosoft DirectX SDKCareful because it looks like there are a lot of dds textures in that folder that you may not want to convert to DXT1. Matt

[Forkboy2 27]

I wonder if just deleting some of the Bump and Specular files will make an improvement. Do we reallyneed bump and Specular files for all the autogen vehicles, etc?Matt

[FlyingsCool 3]

Why would you not want to convert them to DXT1? What would we need to look for?Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

[FlyingsCool 3]

If the bump map is a special file, how does FSX determine if it needs one or not? Is it doing lots more file searches now, and is this causing a performance issue? Or does it just look for the files once during loading and create an index, so really there's no performance hit?Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

[Forkboy2 27]

>If the bump map is a special file, how does FSX determine if>it needs one or not? Is it doing lots more file searches now,>and is this causing a performance issue? Or does it just look>for the files once during loading and create an index, so>really there's no performance hit?>>Thomas>I'm not sure, but the bump and specular files are several times larger than the textures themself so there must be some overhead.Matt

[Forkboy2 27]

Converting to DXT1 could affect transparency, etc. on some of them. Not sure, would really need to look at each texture.>Why would you not want to convert them to DXT1? What would>we need to look for?>>Thomas>

[Sartanius 399]

The texture folder has DXT1, DXT3 and DXT5 files in all sizes (256 x 256 to 1024 x 1024). After converting all .dds to DXT1 I see that they all now show as DXT1 but their sizes (1024 x 1024, etc.) and file sizes are unchanged. Texconvert.exe ran just fine and I watched it run through all the files.Just what exactly happens to the files when changing from DXT5/DXT3 to DXT1 to improve performance? I thought the texture size had to be reduced to improve performance.DougDell XPS Gen3 (3.6GHz/800FSB) | 2GB DDR SDRAM | 74GB SATA, 10k RPM (C: ) | 120GB SATA (D: ) | 512MB ATI Radeon X1900XTX (Catalyst 6.8) | Audigy 2 ZS Sound | MS Force Feedback 2 | WindowsXP Pro (SP2) | DirectX 9.0c

[FlyingsCool 3]

Well, in resizing all the textures (I have all the textures >342KB cut in half, and plan on resizing the 171 KB textures as well), I found one texture that was affected so far: do not dxt1ize AirportParkingSpace.dds .Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

[FlyingsCool 3]

While their size remains the same, the disk space and therefore the memory they take up is significantly reduced. However, perhaps you are correct in some ways, as these file types are all about types of compression used. I don't know if they take up any less memory once loaded up in graphics. I believe they do, however, as it is well known that DXT3 images are much smaller and provide better performance in most cases than 32 bit textures.Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

[Forkboy2 27]

DXT1 is same as DXT3 but alpha channel is different. So if a DXT3 texture has alpha channel and you convert to DXT1, weird things can happen.I don't think there is any difference at all between BMP and dds if they are the same format. By the way, XN View works great for reducing file size of dds textures in batch mode. Just use XN View to reduce size, then Imagetool to add mip maps back in. I reduced all my generic ground textures from 1024x1024 to 512x512 last night. Went from 5 gigs to 1 gig with little change in quality unless you have detail slider set pretty far to the right.Matt

[Sartanius 399]

Thanks for the explanation, guys.DougDell XPS Gen3 (3.6GHz/800FSB) | 2GB DDR SDRAM | 74GB SATA, 10k RPM (C: ) | 120GB SATA (D: ) | 512MB ATI Radeon X1900XTX (Catalyst 6.8) | Audigy 2 ZS Sound | MS Force Feedback 2 | WindowsXP Pro (SP2) | DirectX 9.0c

[scott967 62]

DXT1 requires 4 bits / pixel. DXT3 and DXT5 require 8 bits / pixel. This is before adding in mip-maps. the difference of DXT3 and DXT5, is that DXT3 directly encodes (no loss of information) a 4 bit alpha channel. Of course, if your original texture is 32 bit, you must somehow reduce the 8 bit alpha channel to 4 bit, before converting to DXT3. In DXT5, a lossy compression technique is used that compresses the 8 bit alpha into 4 encoded bits.My understanding is that the advantage of the DXT format is that you only need to push the 4 or 8 bits/ pixel to the vid card, which does the reverse uncompression on card.scott s..

[Guest emkramer]

When this gets all sorted out, it would be great if someone could write a batch file that would dxt1-ize all the textures that should be dxt1-ized, and upload it to the library. Or something.

[Forkboy2 27]

>DXT1 requires 4 bits / pixel. DXT3 and DXT5 require 8 bits />pixel. This is before adding in mip-maps. tI'm pretty sure DXT1 and DXT3 are exactly the same, except for the alpha channel (1 bit vs 4 bits). So if there is no alpha channel then should always use DXT1 instead of DXT3 to save 50% on file size and extra overhead that comes with loading an unused alpha channel.You can run into problems when converting a DXT3 texture with an alpha channel directly to DXT1, at least when using Imagetool. I'm not sure but I think one of the bits of the alpha channel is interpreted as black so when the conversion is complete you see a lot of black areas on the texture where they shouldn't be. To get around this, you first have to convert to a texture format that has no alpha channel at all to clear the alpha channel. This is one of the reasons that I wouldn't do the hack described in this post. There are all sorts of weird things that can happen when you go directly from 4 bit alpha channel to 2 bit alpha channel.Matt

[Guest B1900 Mech]

Thankyou for the help!:-)