Texture formats
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Thread: Texture formats

  1. #1

    Texture formats

    A thread in the FS9 forum got me wondering about aircraft texture formats. This person said that the extended bit 565 format was better than other formats like DXT3. This is not to dispute this persons comment, since all computers are different, this format may work perfectly for them. It does not work for mine. The only format that works for me to save in is DXT3. DXT1, extended bit 565, etc are very blurry and distorted on my computer, however, here is the odd part, if I download aircraft textures saved by someone else in either the 565 or DXT1, my computer shows them just fine. So, it makes me wonder if I am doing something wrong or is my computer, game, video card set up wrong? I do have mip maps unchecked, btw.

    I also wonder if the majority of you are having better luck with DXT1 or 565 formats, if my aircraft textures are blurry or distorted on your computers, since I only save in the DXT3 format?

    Thanks!

  2. #2
    Quote Originally Posted by RobH View Post
    A thread in the FS9 forum got me wondering about aircraft texture formats. This person said that the extended bit 565 format was better than other formats like DXT3. This is not to dispute this persons comment, since all computers are different, this format may work perfectly for them. It does not work for mine. The only format that works for me to save in is DXT3. DXT1, extended bit 565, etc are very blurry and distorted on my computer, however, here is the odd part, if I download aircraft textures saved by someone else in either the 565 or DXT1, my computer shows them just fine. So, it makes me wonder if I am doing something wrong or is my computer, game, video card set up wrong? I do have mip maps unchecked, btw.

    I also wonder if the majority of you are having better luck with DXT1 or 565 formats, if my aircraft textures are blurry or distorted on your computers, since I only save in the DXT3 format?

    Thanks!
    I've found that it depends on what its for. AC DXT1 works for alpha channeled parts. Where DXT3 can cause issues with shadows. Mostly holes in the shadows. All other parts the Extended Bit 565 works best.

    Same for ground objects. DXT1 works best. DXT3 might not show compounded objects. Other objects the ACs shadow might not show if you have a large alpha channel on the object. I discovered this while doing the euro buildings and trees.

    Now this is on my computer. Others might not have the same issue.
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  3. #3
    SOH-CM-2016 kelticheart's Avatar
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    Icon22 Colour bleed topic again

    I have found that DXT1 and DXT3 formats generate always a definition distortion called in several very old threads 'colour bleed'.

    A problem that worsens steadily with each new save of the file after editing. The colour shades are somewhat turned into square shaped areas, easily seen when zooming in the texture, while part of each tint actually bleeds from darker tones squares into lighter ones and viceversa.

    Stock CFS2 aircraft textures are all 'DXT1-no alpha' (I am using Martin Wright's DXTbmp terms, as there is a DXT1 with and a DXT1 without). They look nice from a distance, but then look more blurred at very close ranges. Zoomed in with any graphic editor, they reveal the squared texturing I spoke about.

    Edited and saved as DXT1 around three to four times in a row, 'colour-bleed' effect increases and they degrade real fast, to the point that panelling and rivets almost disappear.
    The edges of details that should look sharp, like nationality roundels or stencilled characters, increasingly blend in with the surrounding colour to the point that they look as blurred as if they were seen under water without a mask. Not speaking of straight lines or curves, which turn out a total mess. DXT3 is even worse than DXT1 in this aspect, one edit and save and the texture is already badly compromised.

    Extended format with alpha texture becomes unavoidable when painting damage textures that will display with empty areas. I resolved the degradation problem in part here by saving the texture in 16 bit 565 after each editing, then joining it with its alpha textures in DXT1 format only at completion. One save, the very last one, while I keep a copy in 565 format just in case I needed to go back and further edit it.

    On the other hand, just everybody else that experienced with the same textures, saved as 16 bit 565 and DXT1 or 3, reported that animation rate improves with DXT format textures.

    Since I find very often details in need of touchups, I am forced to save my editing jobs always in 16 bit 565 format. I must admit that my CFS2 is not that fast, even if there are many other factors slowing down framerate, such as increased detailing of the models over the years, model conversion from civilian sims without multi-LOD, improved effects, more detailed ground mesh and so on. I eliminated mipmaps a while ago.
    The age of my rig doesn't help either, even if its performance is still top notch, according to all the checkup utilities I use.

    When I switch from DXT1/3 to 16bit 565 textures, I can tell the difference. To the point that lately, when I have the rare time to fly a mission, providing it does not involve ground attacks, I start CFS2 with an empty cfs2.gsl file, so that all my computing power is devoted exclusively to displaying aircrafts.

    No one ever came up with a solution to avoid 'colour bleed' with DXT formats, yet I have seen many times DXT textures displayed with very high definition and almost undetectable colour bleed. I wonder what paint program allows that (and how user-friendly it is.....).....

    Cheers!
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  4. #4
    Member gaucho_59's Avatar
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    I think I cited this measure before...

    Quote Originally Posted by Blood_Hawk23 View Post
    I've found that it depends on what its for. AC DXT1 works for alpha channeled parts. Where DXT3 can cause issues with shadows. Mostly holes in the shadows. All other parts the Extended Bit 565 works best.

    Same for ground objects. DXT1 works best. DXT3 might not show compounded objects. Other objects the ACs shadow might not show if you have a large alpha channel on the object. I discovered this while doing the euro buildings and trees.

    Now this is on my computer. Others might not have the same issue.

    I noticed this a long time ago... the increasing deterioration of extended bmp bitmaps with successive "edits" of a texture... so called "moireau pattern" effect on color shades and loss of finer detail... The way I got this over... was to:
    1. make a PSP or PSD copy template of the intact texture... in high-def colors and do the editing on that...
    2. then replace the aircraft texture with an extended bmp copy via Wright's program.
    3. Then, every time I need to add or change the texture... I open the template... change it in PSP or Photoshop an replace the new version on the aircraft texture folder... in place of the one that needed editing...
    With this method, there is no an iota of change in color or shape fidelity... I NEVER OPEN, EDIT AND REPLACE THE OLD ONE! Hope this is of help...

    The one thing that keeps me puzzled is that CFS 2 aircraft textures as well as FS9 - highly detailed originals - when edited never show again (at least in my computers -different ones as I change to newer and better rigs) unless they are put on 256 colors... I mean... the original is 8 bit color, and not extended, but its edited copy does not show if put back after edit... the plane shows blank textures just plain gray... then when I reduce the color ... it shows... but not as nicely as the high-def edit....
    so... I started the method described above... and replace them as extended bmp files... and this resolves the problem for me... I think I basically do what Kelticheart describes here...

    G.

  5. #5
    Thanks everyone!

    I do save my textures after changes are made in my Photoshop. I save them as a bmp file and usually 32 bit. I have tried 24 bit, but cannot tell much difference, and 16 bit pretty much destroys it. I then use dxtbmp to open the bmp and then save my new texture directly into the airplane texture folder. I do not think its the process that is causing the problem, I wonder if its my computer or my video card. I just find it odd that the only format that works well on my computer is the DXT3 in CFS2.

  6. #6
    Just to chip in some things I've noticed.

    I try to avoid DXT with alpha because of the "bleed" issue, but by bleed I mean how it draws MIPS in sim. With the DXT formats you can still be quite close by & the aircraft (or ship - especially ship) textures suddenly looks blurry & blocky as the sim redraws & chooses to downsample (MIP).

    Try the same thing with 565 etc. formats, & the effect is still there, but much less noticeable.

    Over the years my format choices with DXTbmp for repaints have become:

    uncheck the "include MIPS" button - with faster processors these days the sim can do this on the fly & it will make better choices than DXTbmp.
    Make sure you have the latest version of DXTbmp & the latest dlls

    Texture formats themselves:
    • no need for an alpha channel (eg. normal undamaged fuselage & wings, usually DXT1 no alpha) - use 565
    • simple pure black alpha (eg damage textures, usually DXT 1 with alpha) - use 555-1
    • partial, graded alphas (usually DXT3) - 444 or even 888 - depending on the application (prop blurs or windows) doesn't always give acceptable results, so sometimes only DXT3 will do, but sometimes these formats will improve appearance in the sim.

    However, don't use these formats for bitmaps that don't require an alpha, something I noticed when using 888 format for bitmaps where you don't need an alpha channel. They can look downsampled as though they've gone to 16 bit colours. Saving with a pure white alpha seems to improve things, but 565 format actually appears better. So although 888 is able to use 32 bit colour, the sim seems to take it back to extended 16 bit colour.

    Hope this is useful

  7. #7
    SOH-CM-2016 kelticheart's Avatar
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    Quote Originally Posted by UncleTgt View Post
    Just to chip in some things I've noticed.

    I try to avoid DXT with alpha because of the "bleed" issue, but by bleed I mean how it draws MIPS in sim. With the DXT formats you can still be quite close by & the aircraft (or ship - especially ship) textures suddenly looks blurry & blocky as the sim redraws & chooses to downsample (MIP).

    Try the same thing with 565 etc. formats, & the effect is still there, but much less noticeable.

    Over the years my format choices with DXTbmp for repaints have become:

    uncheck the "include MIPS" button - with faster processors these days the sim can do this on the fly & it will make better choices than DXTbmp.
    Make sure you have the latest version of DXTbmp & the latest dlls

    Texture formats themselves:
    • no need for an alpha channel (eg. normal undamaged fuselage & wings, usually DXT1 no alpha) - use 565
    • simple pure black alpha (eg damage textures, usually DXT 1 with alpha) - use 555-1
    • partial, graded alphas (usually DXT3) - 444 or even 888 - depending on the application (prop blurs or windows) doesn't always give acceptable results, so sometimes only DXT3 will do, but sometimes these formats will improve appearance in the sim.

    However, don't use these formats for bitmaps that don't require an alpha, something I noticed when using 888 format for bitmaps where you don't need an alpha channel. They can look downsampled as though they've gone to 16 bit colours. Saving with a pure white alpha seems to improve things, but 565 format actually appears better. So although 888 is able to use 32 bit colour, the sim seems to take it back to extended 16 bit colour.

    Hope this is useful

    Hi UncleTgt,

    thank you for this explanation coming from your experience. Let me ask you, what about framerate? Did you notice any improvement when placing a good number of AI planes dressed with DXT1/3 textures in the sky?

    Another comment, my pc is quite old but I discovered a while ago it handles textures without MIPS quite well. I believe thanks to AMD technology of handling more 3d instructions with the processor, instead of relying only on the video card.

    Friends of mine with Intel-based machines, of similar performance specs, were never able to display CFS2 full graphics potential as I do.

    Cheers!
    KH
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