Mipping of Ground Textures

[PebbleBeach 120]

Hello All,

I am working on KRNO as you know. I'm making ground textures for the surrounding area.

I have a question un-related to this. My question involves the default ground textures we use in FS2004. You know the ones labeled for example:
029b2su1.bmp, 029b2fa1.bmp, 029b2wi1.bmp, 029b2hw1.bmp, 029b2lm1.bmp etc. etc.? My question is more directed towards the LM default
textures. The light map textures for night time. I have completely redone these textures to my liking. My questions:

1. Should I mip these? 
2. If doing so, will it cause a CTD?
3. Any benefit in doing so?

Your thoughts.
Always appreciated,

Mitch

•  
• Quote

[trioer 10]

Hi Mitch,

I'll see if I can pull it up, but there was a big discussion on Alpha India forums about what to mip and not. As I recall, any lights should stay as is, whether scenery or aircraft or panel, etc etc. So that is what I have always gone by. I have a program, mipmap checker or something, I am at work and don't know off hand, that I run sceneries through and I don't mess with any LM ones and I haven't had any trouble. I did do a few FlyTampa sceneries completely when they first came out, and I had to re download because it messed up everything. 

TL:DR I wouldn't touch the LM's in my humble, non factual opinion.

Edited January 27, 2022 by trioer

[hjwalter 25]

• I've always been lead to believe that ALL textures which are normally viewed from varying distances, should always be mipped, solely because of frame rate advantages. In my opinion this means that EVERYTHING which is not a flyable aircraft texture, should always be mipped, simply because what's the use of your graphics system getting all hot and sweaty when needing to render far too detailed textures, when they are in fact so far away that you cannot even see those details.
• As far as I'm concerned, this also hold true for night textures, which may structurally already be less detailed.

          Can anyone bring me off these beliefs ?

          Regards

          Hans

 

 

[trioer 10]

Here's what I pulled from Alpha India discussion. It mainly discusses AI, but note the point on FlyTampa Sceneries. Also note the part about never mipping AI Aircraft Lights and making sure ALL DXT3 textures have an Alpha Channel.

Mip maps are essential for textures to be rendered properly in FS - the graphics card is looking for them, when it doesnt find them, it in effect "panics" and applies filtering on them, which is one of the main causes of shimmering.
Its hard to imagine, but if you think of an eye viewed sideways - wide at the front and coming to a point at the back. Imagine the graphics card as that eye, different textures are hitting the edges of that eye from different distances, from close up they will be big and hit the edges at a large size, but as they get further away they hit the edges of the eye further back, therefore they need to be smaller to remain in focus. This is exactly what mip-maps do.
Hard to imagine I know without a diagram.

One of the reasons FlyTampa sceneries run so well is all their textures are mip-mapped.

DXT1 with mips and DXT3 with mips are truly SDK compliant texture formats, 32bit with no-mips certainly is not !

I have mipped all my AI textures and I cannot believe the difference. No stutters whatsoever, even at Heathrow, and the textures are fabulously smooth, not a shimmer to be seen.
If at anytime you see a texture that has blurred, using the + or - key will get it to sharpen up immediately.
Lightmaps should not be mip-mapped, neither should VC textures for flyable aircraft.

Also during my research I found that converting from 32bit to DXT3 in DXTBMP sometimes removes the Alpha Channel. Having a DXT3 texture with no alpha channel is the biggest single cause of stutters you could imagine.
I have been through every single AI texture I have (yes really !) and I could not believe how many textures I have downloaded that do not have Alpha Channels. No wonder my system was stuttering like streaming video on dial up.

All my releases in future will be full SDK compliant textures, so DXT3 format with mip maps.
If you wish to remove them then that can be done easily with DXTBMP.

One final thing, I found out that using imagetool to add mips in a batch command would remove the alpha channel if the alpha was white - so you have to do it individually or using DXTBMP.

[hjwalter 25]

Hey guys,

On the blurries subject I've read in this forum that if any scenery's textures, or any of those coming from the main texture folder, contain a mix of mipped and unmipped textures, frame rate and blurriy issues can occur. This was in fact my main reason to mip all scenery, AI aircraft and main texture folder textures, leaving only the flyable aircarft textures unmipped because, in my mind, these are normally never viewed from varying distances.

A theoretical question therefore:

If you view a flying flyable aircraft from the outside against a background of moving mipped scenery textures, will this then have the increased potential to cause stutters and/or blurries and/or framerate issues ? Would there be any good reason to NOT mip flyable aircraft textures ? Mipping these do not (yet) seem to cause any problems, as I've done a few tests with this and as yet see no real issuess but which could certainly occur under more complex conditions.

Any comments are welcome and appreciated.

Regards

Hans

 

[edetroit 933]

I mip all scenery and AI. My flyable are all 32 bit no mips. The most important thing is to check all add-on scenery and AI for alpha channels.

Pretty much 90% if not more sceneries are missing alphas.

My FS9 runs nice and smoothly and I plan to keep it that way for years to come. 😁

Regards

Ed

 

[PebbleBeach 120]

9 hours ago, edetroit said:

I mip all scenery and AI. My flyable are all 32 bit no mips. The most important thing is to check all add-on scenery and AI for alpha channels.

Pretty much 90% if not more sceneries are missing alphas.

My FS9 runs nice and smoothly and I plan to keep it that way for years to come. 😁

Regards

Ed

 

Ed,

I'm a little confused. That's what I do often. Get confused. 😃

So after reading these posts, and thank you for everyone who responded, I'm still not sure what to do. I'm referring to the night ground textures. For example, located in FS9/Scenery/World/Texture the files labeled 029b2lm1.bmp-029b2lm7.bmp so on and so on. These textures. Can I, should I, MIP these. Yes or No. 

I've received excellent advice over time from many. Dedl from Germany helped me immensely. But honestly, I am a hands on guy, a builder, and a programmer. Hence my flight simulator. I still do not have the time to understanding of images, alpha channels, mips, etc. etc. 

I enjoy creating textures. Textures that make my FS9 seem more realistic based on the many real world flights I do. Perhaps I simply need to create, and then forward to someone with a better understanding, to complete prior to release.

Frustrated,

Mitch

[PebbleBeach 120]

Ed?

 

[hjwalter 25]

Mitch,

I would want to suggest that you first back up your complete world/texture folder (could take quite a long time) and then mip the selected night textures in your original texture folder to see what happens in one or more previously saved (test) setups. If something goes wrong or you see something not to your liking, you can always restore the folder which you had backed up.

However, mipping any world/texture folder textures should not do any harm anyway.

Regards

Hans

[PebbleBeach 120]

I'm struggling right now but thank you everyone for your advice. You have no idea how much I appreciate it.

 

[neumanix 114]

The general rule of thumb is to add mipmaps to textures that are viewed from greatly varying distances, i.e. scenery, clouds and AI aircraft.

I've always done it for lightmaps as well without any issues. For easily making sure your textures have proper alpha channels, use my dxtfixerX tool, link below.

Edited February 10, 2022 by neumanix

[PebbleBeach 120]

On 2/10/2022 at 4:32 AM, neumanix said:

The general rule of thumb is to add mipmaps to textures that are viewed from greatly varying distances, i.e. scenery, clouds and AI aircraft.

I've always done it for lightmaps as well without any issues. For easily making sure your textures have proper alpha channels, use my dxtfixerX tool, link below.

Peter, and everyone else who responded, thank you all for sharing your knowledge. Greatly appreciated. I have been under the weather (sick) for several days now and I apologize for not having responded to each and every response. I beg that you understand I sincerely appreciate every response as I understand it took time away from your normal activities. Thank you again.

I am now to the realization that mipping these night textures is safe to do. I plan on using "Mipmap Manager" to do so. But Peter? You bring up another area that I'm totally word not allowed about. "Alpha Channels". 

1. What are they?
2. How do they effect the visual texture? What is the benefit?
3. And do I use "DxtfixerX" tool after I've added the mips in "Mipmap Manager"?

Still confused,

Mitch

[neumanix 114]

The alpha channel are the bits in a image file that describe what parts of that image is transparent, and how transparent it is.

Take a fence texture for example. You want to see the wire but the rest needs to be see-through.

A lot of textures don't need any such information, a brick wall for example.

Developers work in 32 bit and then convert (and compress) down to dxt1 or dxt3 that are both special directX texture formats.

If a textures alpha bits are all 1's, i.e. all white which means 100% opaque, and it's converted to dxt3 with ImageTool, then one bit in the file header gets set wrong and the sim interprets this as the image having no alpha info at all.

This causes long stutters that you notice when looking around at an airport.

So dxtFixer doesn't add any alpha info, it just makes sure that textures always report having an alpha channel, which cures these stutters.

Yes, use dxtFixer after you've added mips and always after installing anything that has textures (scenery, aircraft...)

 

Edited February 13, 2022 by neumanix

[PebbleBeach 120]

On 2/13/2022 at 4:46 AM, neumanix said:

The alpha channel are the bits in a image file that describe what parts of that image is transparent, and how transparent it is.

Take a fence texture for example. You want to see the wire but the rest needs to be see-through.

A lot of textures don't need any such information, a brick wall for example.

Developers work in 32 bit and then convert (and compress) down to dxt1 or dxt3 that are both special directX texture formats.

If a textures alpha bits are all 1's, i.e. all white which means 100% opaque, and it's converted to dxt3 with ImageTool, then one bit in the file header gets set wrong and the sim interprets this as the image having no alpha info at all.

This causes long stutters that you notice when looking around at an airport.

So dxtFixer doesn't add any alpha info, it just makes sure that textures always report having an alpha channel, which cures these stutters.

Yes, use dxtFixer after you've added mips and always after installing anything that has textures (scenery, aircraft...)

 

Bingo. Great and informative reply. Thank you so very much. Making note of this and adding it in my scenery journal. Thank you again Neumanix..