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Will FSX be another huge .BMP program???

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Guest Water Mango

Just wondering will FSX be another bloated '.bmp' application. '.jpg' files take up allot less space but I've read there are other alternatives that are even smaller than '.jpg' files with the quality of '.bmp' files.It would be nice if FSX pulled away from such a bloated file system for textures...

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I'm no expert, but my understanding is JPGs are smaller files, but would actually take up a lot more memory than the compressed BMP format used by FS. Plus you have more resources required to decompress the JPGs. Matt

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Exactly! BMP files can be loaded and displayed directly. JPG files need processing effectively into bitmaps first which slows down their loading and display.

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Guest

and of course JPEGs are actually lower quality by definition than BMPs made from the same data, simply because of the lossy compression algorithm used.You also can't embed things like alpha channels in them.The loading mechanism is a lot more complicated as said.With a BMP I can determine which part of the texture file I need and read just that from the file if I want to. With JPEG that's impossible, so your memory requirements likely go up.

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Guest EdrickV

If harddrive space really is a consideration, you are using XP, and your harddrive is formatted in NTFS (If your computer came with XP then chances are it's NTFS) then you could try this trick:Select all the folders in your aircraft directory, (or at least all the ones not used as AI aircraft) right click to get properties, click "Advanced..." and then put a check in the "Compress contents to save space" box. Then hit OK, choose to apply to subfolders and files, and go get a snack or something, this'll take quite a while.I compressed my entire aircraft folder and saved about 6 out of 9 gigs! (In otherwords Size: 10,046,665,700 bytes, Size on disk: 4,042,955,011 bytes) I haven't noticed any preformance issues now that I didn't already have before doing that, but you could just compress your non-AI aircraft. You can only fly one at a time afterall. ;)The reason it compresses so well that way is because the textures are bitmaps and thus uncompressed. (Memory wise I think a jpeg would take up the same amount of memory, require more processing power because it would have to be decompressed to use it, and would loose some quality in the process. This trick doesn't compress the files as much, and the decompression code is built into Windows and should be transparent to FS9.)You can always uncompress the files if it causes you preformance problems. (Just go back and uncheck the checkbox, but make sure you have more then enough space, because "size on disk" is normally a bit higher then the actual size of the files.)I have not tried this with my addon scenery folders yet. (Aircraft, for me, are the biggest users of harddrive space. And most of them will not be used in any one flying session.)"Let me help you out. You're cleared to taxi any way you can to any runway you see."

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>With a BMP I can determine which part of the texture file I>need and read just that from the file if I want to. With JPEG>that's impossible, so your memory requirements likely go up.Not sure what you mean by this.???>You also can't embed things like alpha channels in them.Does that matter.Unless the troops have done something pretty slick at FSwe are going to end up with atexture mapreflection mapbump maplight mapso would a transparency map make much difference.???Tas

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>"Can you imagine trying to edit JPEGs">>So what is so hard about editing Jpg's ??Guess he's out for recompression => quality loss. Didnt quite follow the whole thread though (I'm kinda lazy today), so correct me if I'm wrong. :)

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>"Can you imagine trying to edit JPEGs">>So what is so hard about editing Jpg's ??>>>Every time you open, edit and resave a JPG, the quality goes down a little bit because it's recompressed. Even if you just change 1 pixel, the entire image is recompressed.Although, there are some image editing programs that are starting to get around this.Matt

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>>You also can't embed things like alpha channels in them.>>Does that matter.>Unless the troops have done something pretty slick at FS>we are going to end up with a>texture map>reflection map>bump map>light map>so would a transparency map make much difference.???Er, the "reflection map" IS the alpha channel of the texture map......and the "transparency map" or "light map" REQUIRE{/b] the alpha channel to control which electrical buss is used, so yes, it makes a LOT of difference!

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Guest

There is no getting around it. At most you could calculate exactly which parts of the file were changed and then calculate exactly what that change is, then write only the changes.This would in theory leave most of the image untouched on disk.Of course if you change something that's in an area with a lot of identical colour you're still going to get massive changes to the file on disk because of the way the compression algorithm works.Pretty nifty idea though, impractical to say the least until recently because of the amount of computing power needed to perform such calculations rapidly enough that saving a moderately sized file doesn't take an hour :)

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>>"Can you imagine trying to edit JPEGs">>>>So what is so hard about editing Jpg's ??>>Guess he's out for recompression => quality loss. Didnt quite>follow the whole thread though (I'm kinda lazy today), so>correct me if I'm wrong. :)That's right :). I'm partial to using the "flood fill" tool in Paint Shop Pro*. The "artifacts" left over by JPEG compression are a flood filler's nightmare :-boom(* yes, Jeroen, I have a legal copy of PSP 8, purchased online for

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Guest

>>(* yes, Jeroen, I have a legal copy of PSP 8, purchased online>for

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Matt,When you open a jpeg then close without re-saving,does it lose anything?Peter Sydney Australia

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Guest EdrickV

If you don't click save then it's not modifying the file on the harddrive. It just copies it into memory."Let me help you out. You're cleared to taxi any way you can to any runway you see."

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>> Er, the "reflection map" IS the alpha channel of the texture map...But only on planesYou have to do something tricky with scenery.>> .and the "transparency map" or "light map" REQUIRE{/b] the alpha >> channel to control which electrical buss is used, so yes, >> it makes a LOT of difference!"Electrical buss" in Scenery ???

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>>> Er, the "reflection map" IS the alpha channel of the>texture map...>>But only on planes>You have to do something tricky with scenery.>>>> .and the "transparency map" or "light map" REQUIRE the>alpha> >> channel to control which electrical buss is used, so yes,>>>> it makes a LOT of difference!>>"Electrical buss" in Scenery ???I'm an aircraft developer, so I responded the OP's question - which was not limited in scope to scenery only - from the POV of aircraft textures.Certainly scenery uses a slightly different approach, yet the alpha channel persists as a requirement, even when using xxx_LM.bmp images for lightmasking.

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