FSX and lightmaps

Some of you may or may not have noticed the use of light maps on some of the aircraft - for example, the A321 has two bitmaps with *_LM.dds naming. Others you see have *_night.dds. Well, I just posed this question to Adrian Woods, an ACES developer, and here was his reply:

Owen wrote:
If a part has a light map, for example, I see in the heavies several *_LM.dds - does this need to be designated in the material in the self-illumination section?

Adrian wrote:
Yeah. The only time it doesn't need to be defined in the Self-Illumination section is if you leave it as a standard material. Then it will revert to FS9 functionality. The nice thing is now you can name your night maps anything you want.

Best regards,

Owen
 

nickw

Administrator
Staff member
Great info Owen.

Adrian, you are a legend... you may as well come here and create an account ;)
 

n4gix

Resource contributor
Now here are a few interesting questions...

In FS2k4 & FS9, _LM files were explicitly designed for scenery. In fact, the properties of _LM lightmaps were replacement for the Diffuse Color texture.

The properties of aircraft _L files on the other hand, are additive, meaning that they "added to" rather than "replaced" the Diffuse Color texture. Additionally, the shade of the Alpha channel determined which light bus would control the use of the lightmap: landing light - or - any other light bus.

Is that still the case now?

Do _LM lightmaps make use of the Alpha channel?

What is the principle advantage of using _LM vs. _L techniques?
 
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arno

Administrator
Staff member
FSDevConf team
Resource contributor
Are we not talking about lightmaps and nightmaps here? They indeed behave different in Fs2004. The nightmap replaces the day texture, while the lightmap is blended. The confusing thing here is that the _LM textures are usually used as nightmaps :confused:

Speaking of scenery only, it was already possible in Fs2004 to use a different name for your night texture, the _LM prefix was not required on 3D objects. Although most designers used it as a standard.
 
Now here are a few interesting questions...

In FS2k4 & FS9, _LM files were explicitly designed for scenery. In fact, the properties of _LM lightmaps were replacement for the Diffuse Color texture.

The properties of aircraft _L files on the other hand, are additive, meaning that they "added to" rather than "replaced" the Diffuse Color texture. Additionally, the shade of the Alpha channel determined which light bus would control the use of the lightmap: landing light - or - any other light bus.

Is that still the case now?

Do _LM lightmaps make use of the Alpha channel?

What is it principle advantage of using _LM vs. _L techniques?
Are we not talking about lightmaps and nightmaps here? They indeed behave different in Fs2004. The nightmap replaces the day texture, while the lightmap is blended. The confusing thing here is that the _LM textures are usually used as nightmaps :confused:

Speaking of scenery only, it was already possible in Fs2004 to use a different name for your night texture, the _LM prefix was not required on 3D objects. Although most designers used it as a standard.
See, this is a great reason why we should get Adrian over here. Nick, you and I need to work on that. :)

From what I gather from looking at the _LM files in the A321 folder, specifically, they appear to work on the "additive" principle instead of the replacement nightmaps of days ago. I state this because looking at them, there is no color aside from the light splashes and windows. If these were replacement bitmaps, would they not exhibit the colors of the aircraft scheme?

It is different in that now we have to specifically designate a self-illumination map in the material properties, where before in FS 9 if we had a diffuse texture named _T.bmp, the game engine assumed there would be a corresponding _L.bmp. Because we specifically designate that map, we can call it what we like.

Now, I'm no scenery person, and I have no idea how nightmaps are being addressed. *Hopefully* we can get a member of ACES in here who is more knowledgable and could go into more specifics regarding night lighting and scenery.

Best regards,

Owen
 

nickw

Administrator
Staff member
I'm pushing... though I understand how difficult it is for them to get time.... and also know they are "protected" from the muppets.
 
I'm pushing... though I understand how difficult it is for them to get time.... and also know they are "protected" from the muppets.
Yeah, I realize that as well, but it should be an advantage to them to have a single, happening place for them to come and give dev advice, instead of having to bounce here there and everywhere, and we know how much time that takes (right, Bill?).

Best,

Owen
 

n4gix

Resource contributor
Er, yep... it now takes me up to three hours just to make the daily rounds of email, newsgroups and forum diving... Too little information spread around much too thinly. It's a lot like eating a bologna sandwich with next to no mayonaise <blech!>

Yes Arno, that is indeed my point. ACES is now conflating two perfectly good and rational "schemes" into one filename. Given that you can name the aircraft lightmap anything you want, it seems pointless to co-opt the scenery's nightmap _LM extension. This is just going to confuse everyone! :eek:

Owen, I've been using the Self-Illumination slot in FS9 models all along! I never have allowed the sim to "assume" anything about what I wanted to do... :D

In fact, my practice has been to assign Diffuse Color, Specular Color and Self-Illumination for all relevant material whenever I first create them. :cool:
 
Owen, I've been using the Self-Illumination slot in FS9 models all along! I never have allowed the sim to "assume" anything about what I wanted to do... :D

In fact, my practice has been to assign Diffuse Color, Specular Color and Self-Illumination for all relevant material whenever I first create them. :cool:
And that worked perfectly fine, but for those of us who *didn't* specify, then the naming scheme kicked in. Now we will all have to adopt your well versed practice. :D

Best,

Owen
 
Hi, just a quick question about lightmaps in FSX.
I have to export a previous FS9 Gmax model in FSX, i've done some tests and all works fine, except for those materials with the BRIGHT_ attribute. No matter if put an _L or _LM bitmap in the self illumination channel, the surface does not self illuminate at night. Is there a workaround for this problem? :confused:
 
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