Saving texture files as 'DXT3' or 'Extended 32 bit 888-8'

[Jim77]

I see in my aircraft texture folders that some files are visible (I can see the fuselage, wings or whatever), and some it only has the generic MS Photos icon, not the 'picture' of what the file is. The MS Photo icon files are all saved as DXT3. The ones I can see are Extended 32 bit 888-8. The properties 'Item Type' of both are BMP files.

 

For the MS Photos icon only files, I see what the file 'picture' is when I open it with DXTBmp. Each file is named of course, but without opening with DXTBmp I cannot see exactly what the file contains. If I open the icon only file with DXTBmp then my paint.net editor, make changes to the file (change N#, add stripes), and change the 'Save as Type' from DXT3 to Extended 32 bit 888-8, then the icon only file is now visible. It is also a lot larger file, about 1 MB to now 4 MB. Saving as Extended bit 32 seems to make the aircraft image sharper when flying.

 

Is there a best way to save, DXT3 or Extended 32 Bit 888-8? Sacrificing hard drive space for a sharper aircraft? Hope I explained this clearly enough. I'm using FS2004. Thanks in advance.

[douga66]

The very simplified answer is use DXT3 (or DXT1 with alpha for lightmaps) for performance as this is the recommended format in the sdk. The 32 bit version when saved with DXTBmp or Imagetool is a larger version with much less compression which in turn displays a better quality images. On older systems the performance would take a hit from this as well as uses extra HD space. Newer computers should not have a problem with this however. Still the hard drive space can be used up much quicker with these larger files especially for flyable aircraft.

[tgibson_new]

My rule of thumb is to use 888 for flyable aircraft when it does indeed lead to sharper display. For AI and other situations I use DXT.

[defaid]

Hi.

 

I use 888-8 for all player and AI aircraft, but then my SSD is about the size of the warehouse at the end of Raiders of the Lost Ark. I'm not zealous about it - any new downloads or creations are converted to 888-8 but I have many that are untouched. If I don't intend to edit, then DXT3 is fine.

 

As Tom has pointed out, the drawback with 888-8 is file size.

 

The main drawback with DXTx is that the compression is lossy, which is to say every time you save & exit, the image is dithered and detail is lost. The dithering is cumulative and over the course of several edits you end up with rather sh**ty textures.

 

32-bit (or 888-8) is an uncompressed format so save & exit has no detrimental effect on the crispness. Also, saving in that format automatically adds an alpha channel if none previously existed (the -8 part).

 

I've not yet had need to edit any other textures (terrain, scenery et c.) so they are still in their original DXT1 or DXT3 formats.

 

If you have the storage, choose 888-8 but keep a copy of the original - I did once convert a bunch of addon airport textures (LICJ) and found that for some reason overhead streetlights on the apron got messed up.

 

D

[johnhinson]

For the MS Photos icon only files, I see what the file 'picture' is when I open it with DXTBmp. Each file is named of course, but without opening with DXTBmp I cannot see exactly what the file contains. If I open the icon only file with DXTBmp then my paint.net editor, make changes to the file (change N#, add stripes), and change the 'Save as Type' from DXT3 to Extended 32 bit 888-8, then the icon only file is now visible. It is also a lot larger file, about 1 MB to now 4 MB. Saving as Extended bit 32 seems to make the aircraft image sharper when flying.

A properly formatted DXT3 file does not contain a preview image - it is a simple as that!

 

John

[Jim77]

Thank you all for the replies.

[defaid]

As Tom has pointed out, the drawback with 888-8 is file size.

 

Reading back, I think I should apologise to both Jim and Tom...

[tgibson_new]

Hi,

 

No problem, I don't have an issue. :)

[eliasfsx]

Hello!!!!... I am VERY NEW here in the repaints...the textures, the editors, the files...etc
some truths that I have "collected":
is it like that?

 

truths:
-fsx (and p3d) use the BMP and DDS texture format... but DDS has the advantage that the image is "flipped" and that speeds up the work for the PC (since the CPU does not have to do that work)

-There are several versions/compressions of BMPs and DDS files of which:
dxt1 (will remove the alpha layer)
dxt5 (with full alpha layer)
(all of these will do a compression and blurring, small spots, etc. will appear in the final result, so the continuous editing... of editing... of editing the file will cause ugly spots to appear)

-and the "extended" versions of which the version:
888-8 32 bits (has no compression, and has full alpha)
(you can edit it as many times as you want, there will be no damage and it is the highest quality...at the cost of the file size) (which could be a problem in fsx due to lack of memory)

-someone recommended "...for your painting and editing work, save everything in 888-8 32 bits...but to publish and fly, save it in DX5..."

A DDS file in 888-8 32 BITS format (pure, uncompressed) weighs:
-1024x1024...4MB
-2048X2048...16MB
-4096x4096...64MB
but... a DDS in DX5 format reduces everything to half the weight (because it compresses and "damages" it)

-in the year 2024, with current PCs...I don't think it is necessary to listen to ACES when it recommended using DX3...or things similar for performance reasons (from those years 2004, 2007)

 

 

-no use mipmaps

questions:
-In addition to DDS 888-8 32 bits, is there another DDS without any compression? (same for BMP) (444...555...565...16,24, 15 bits...etc)

-generally (it may vary) some textures that you can download for your favorite plane have 3 textures (nose, tail and wings of the plane) and weigh between 12 to 40 mb...
but do the same in DDS 888-8 32 bits ALCANSA 192MB!!! (64mb per texture)...and not to mention if the package includes 3 or more liveries

Is there another format, another program, or another way that I don't know of to obtain the same result (without compression, that is, pure and without compression damage to the image) but that results in less weight in MB?

(I open my works with DXTbmp as a conversion program...and I use "Paint.net" as an editing program to paint...and when I save again I return to dxtbmp to save it in dds or bmp)

 

DDS TYPES

Ben Mathis - Artista 3D Freelance & Tutoriales (poopinmymouth.com)

Edited January 12 by eliasfsx

[defaid]

Welcome to Flightsim!

 

I have pretty well all textures (that I've altered or replaced or downloaded) as 888-8 with mo mipmapping. Like you, I don't see the need. I woudn't be surprised to find something, within FS9, that requires a particular format , like the apron lights I mentioned in the earlier post.

 

I'm sure compression was introduced in every arena purely for storage and performance.

 

On a tangent, when using any worthwhile image editing suite, repeated saving of a compressed format doesn't degrade the image until you save and close. If you have the patience, try it. Open a jpeg and click save fifty or sixty times but don't close the image until the final save. Open a copy of the original (so you are starting with an identical image) and save&close&reopen a dozen times. Compare. This will open a wormcan  ...

 

Simply stripping out the mips will reduce filesize and on high res monitors with a decent card unmipped textures look ok to me. If there's no transparency, reflection or any other surface effect strip out the alpha channel too. Do you need 4096×4096. Half the dimension is a quarter of the file size.

 

As far as the file format goes, I haven't a clue. Something like a flac for video would be great.

 

D

[hjwalter]

Hey Guys,

 

In the above posts there are so many different and complicated opinions raised that it becomes very difficult to make out what the general recomendations should be. So, these are my own general recomendations and which are based on my many years of fantastic FS2004 experiences:

 

1. I've understood that in this thread we are in fact only talking about textures used by FS2004 (FS9) and which are almost exclusively in the BMP format and not in DDS (= FSX).

 

2, Textures which are viewed from strongly varying distances, e.g. those used for scenery objects and for AI aircraft, should all be mipped and can be saved in any format depending on user detail preferences and of cause on his/her PC hardware capacities but DXT3 remains the basic norm for all of these.

 

3. Mipping remains generally necessary in order to prevent PC graphics hardware from constantly having to fully render scenery and AI aircraft textures, which are so far away as to be out of sight anyway.

 

4. Alpha channels remain necessary but can sometimes become problematic when called for by older SCASM based (BGL) files.

 

5. Because flyable aircraft are never viewed from greater distances their (normally DXT3 format) textures need not be mipped.

 

Long live FS2004 !!

 

Regards to all.

 

Hans

 

 

[eliasfsx]

Thank you very much for the advice... I think it confirms what I thought... everything is already "seen" when it comes to textures, compressions and files.
 

I know the following is a bit long...but it is VERY interesting experiment...(sorry for my bad English, I only speak Spanish, and I use Google translator to communicate)

 

opinion question....
IA traffic... the original provided by fsx (and fs9)... the typical "orbit airlines"... "pasific airways"... "world travel"... etc. have these characteristics:
-its textures are in 1024x1024
-they have mipmaps
-and I guess alpha channels

 

ask:
Will reducing the size of your textures to 512x512 result in only HALF the RAM usage? (for IA traffic)

...as almost always the AI traffic we only "see" it on the ATC radio and not in mid-flight, sitting in the commander's seat and looking from the window of our virtual vc cockpit... remove the mipmaps and the alpha channel and reduce everything to 512x512 (I'm talking specifically about the original DEFAULT traffic)
Will there be an increase in performance?

I say this because: for me traffic should be that... fulfilling its task as traffic, I don't care much if it has the old or modern KLM livery or "retro" or etc... for me it is traffic, and fsx is a flight simulator (YOUR flight), the AI should "annoy" you and "alert" you that it is there, with you... but I don't care if it has this or that livery. (In fact, in a real training flight simulation, the cockpit, the systems, and the environment, runways, vors... and things like that are simulated in detail... but you never see the traffic from your cockpit. I wanted say...they train for "flight", not to recognize objects in the air)

more questions:

does the DEFAULT traffic... use (difficult to explain, sorry) "common files"... or does it make copies and copies for each plane in the ram memory?
Let me explain: if there are 10 "orbit airlines" 737 airplanes at an airport... are there 10 copies of the same texture in the ram?... or only 1 and does it share them?

..... the same for the traffic sound ia.

 

EDIT:

Yes, I know, 4096x4096 is too much...if it is the external view...and ONLY if the model has many details do I choose that resolution (marks, rivets, small letters, etc)...if not, I almost always go to 2048x2048 ....the problem is the VC (cabin), some models have very high detail in the cabin, even the letters on each switch have "back lighting" (they glow in the dark)...that's why going to 1024x1024 is dangerous because its very poor legibility (you can barely read what is written in the cabin)

counter-questions about traffic ia:
hey!!!, I still fly the default 737 (and the default planes)...and I don't want to reduce the textures of those airlines (the AI uses the same texture as yours)

answer: easy...create a "new" texture folder and place the models that you fly in them, keep the resolution you want, just rename the "similar" folder to the original (example: "orbit airlines 2007" ) and modify the "flightsim" of the aircraft.cfg ...as if it were a texture that you typically downloaded. and then.... you can reduce the original folder of the textures used by the AI as much as you want.

Edited January 14 by eliasfsx

[jgf]

1 hour ago, eliasfsx said:

Will reducing the size of your textures to 512x512 result in only HALF the RAM usage?

Actually it will be 1/4 the RAM (compared to 1024x1024), but at close range, such as sitting at an airport, there will be noticeable degradation of the image.

[jgf]

1 hour ago, eliasfsx said:

Let me explain: if there are 10 "orbit airlines" 737 airplanes at an airport... are there 10 copies of the same texture in the ram?

If the images used are identical only one will be in RAM, referenced by each incidence of its use;  but the slightest difference, such as a reg number, will mean another image in RAM.

[eliasfsx]

 

Thanks for answering... I really don't know many things yet (that's why I ask)

(if there is anyone else who can answer that would be a GREAT help... even the questions above).
First of all, sorry for getting off topic.
Also...sorry for asking here...but I use fsx. It happens that the most appropriate thread I found to ask this... is here in this thread.

 

These questions are for the default AI (and only for them)....
(as few airlines use, "orbit", "world travel", etc.) they use the same textures... also... the license plates (registration number... for example) are "in the air" not in the texture (they have a sign floating above the fuselage)...so:

conclusions (maybe?) (correct me if I'm wrong):
so...there is no memory saving (there are no duplications, when using the same texture, the simulator will use only ONE texture file for the same model and airline in ram memory...regardless of the number of airplanes)

reducing to 512x512 saves ram memory...(but as we said above, the savings will barely be noticeable since it will use only ONE texture and "share" it)

...the user "hjwalter" above responded (I quote):

"..... Mipping remains generally necessary in order to prevent PC graphics hardware from constantly having to fully render scenery and AI aircraft textures, which are so far away as to be out of sight anyway...."

 

Isn't it more convenient to do this WITHOUT mipmaps or alpha channels (the file is lighter)...and also reduce it to 512x512? (just talking about AI traffic, I would never do something like that for a flight model of "ours")

And the sound of traffic? Does it also save using the same file in RAM for the same airplane models?

 

[jgf]

25 minutes ago, eliasfsx said:

there are no duplications, when using the same texture, the simulator will use only ONE texture file for the same model and airline in ram memory...regardless of the number of airplanes

 

Exactly.

 

MIP images work with LOD (level of detail) scales.  Up close you want to see full detail, but there is no need to render detail at a distance since you will not see it anyway.  So at a certain distance the system drops to "LOD2", which is the next smaller image (if the main image is 1024x1024 then LOD2 will be 512x512, half the image dimensions but one fourth the image size), at further distance it will be "LOD3" - half the previous.  This continues with distance til the smallest image is used.  If there are no MIPs the system will use the full size image for each LOD, even though you cannot see the detail, the full size image is loaded then "shrunk" onto the onscreen image, so that aircraft ten miles away that is only a 64x64 graphic is essentially being rendered with a 1024x1024 image (or whatever is default).

 

I'm not sure how FSX handles AI sounds, but in FS9 there are simple sounds for each type of aircraft - small jet, large jet, small prop, etc.  For example, all jet airliners will use the large jet sound, you cannot have different sounds for different airliners (you can change that sound but then all jet airliners will use your new sound);  all AI in range will use the appropriate sound(s) but there will be discreet sounds in RAM for them since they are not all at the same point playing that sound (some are idling, some accelerating, etc.).

[defaid]

8 hours ago, eliasfsx said:

Isn't it more convenient to do this WITHOUT mipmaps or alpha channels (the file is lighter)...and also reduce it to 512x512? (just talking about AI traffic, I would never do something like that for a flight model of "ours")

 

This relates to textures in FS9 but I suspect it is also true for DDS in FSX.

 

Mipmapping is not necessary with modern hardware, not even for AI. Stripping mipmaps reduces file size in storage but increases the video processor and memory load. If storage is a problem then remove them. If video memory is a problem then retain them. Here's a mipped image from Wikipedia.

 

 

The rendering software will choose and render one part of the image depending on the object's distance. If the texture is not mipmapped then the graphics hardware must shrink the image before rendering it. That adds an extra step to the image processing but modern hardware is perfectly capable of doing that and the resizing done by good hardware reduces Moiré shimmer so well that it is not noticable if your hardware is able to run at a reasonable resolution.

 

 

 

My AI textures have no mipmaps. My hardware is not new but does not struggle at all. Even at airports with busy airspace, the framerate has never dropped below 30. My benchmark is UK2000's EGLL with 455 AI aircraft. Almost none of those are mipped.

 

 

 

Resizing your textures from 4096×4096 to 512×512 will certainly reduce storage requirement and memory load but, as JGF pointed out, such aircraft will look very bad if viewed from nearby.

 

I believe that people have reported problems caused by textures that have no alpha channel. I have never experienced any problems but storage is not an issue for me so if a texture has an alpha channel then I just leave it there. If it has none then I don't add one. However, no one has been able to offer a technical reason for retaining them and I don't believe they are necessary if the aircraft has no transparency (windscreen) or reflection (polished paint). Perhaps this time, someone will.

 

D

 

 

[eliasfsx]

Thank you very much for your answers and help.

(thanks for the "welcome to flightsim")

I introduced myself very badly, I didn't make myself known and I started asking questions... so I'll go where I belong (to the fsx section) I'll introduce myself correctly... and I'll ask more questions than those focused on traffic (default). greetings.

[eliasfsx]

Hello... ask some questions in this thread... I also did some tests... if you want to give advice... I will be grateful: