Hello,
I was sure that you would come here, therefore, I will then answer it subject by subject.
Since the BMS era always emerge this topic but since then never find te comprehensive topic or manual about the criteria of the models.
Well, this is unecessary. None active 3D modelers ever needed it. As long as you get some interest about a certain 3D software and make some test and self education, there is no complexity.
there are lot of style of the modelling workflow. and some of them not suit for the game or make the life difficult.
None of active 3D modelers use the same workflow. @Manos1981 , @lazystone , @okayasugf and others all have different workflows with different softwares. Workflow doesn’t matters, as long as the result is kept within given contraints. Which constraints ? 
Also it can be allow to create a common file share place to use them . like the ejection seats , weapons , wheels, engine nozzle, textures. they are provide more standardized look for the game . I mean the afterburner flame texture , light texture etc…
No way. We don’t want our sources to be spread everywhere, and be used even for non Falcon applications. Because models remain owner’s and BMS property, it shall remain protected.
texturing , and unwrapping:
It is not sure if somebody can make a 3d model then they can use the unwrap and after that texture.
Yeah, sure. But this is not the responability of BMS team. This is a general knowledge. If you can’t unwrap, better do some self-education than starting a complex model. This may start from there for Blender
And there for 3DSMax
(you are lucky, this is an official channel).
There is a certain basic level to reach before being a modeler. Guess what ? I never followed a tutorial to learn unwrapping. I just get to uvw tab of 3dsmax and unwrapped a simple R77 model for a static aircraft, like a little modified cylinder and wings. But everything comes step by step. It’s like being a fighter pilot : you start with small prop aircraft and then fly a Rafale of a Tornado. 3D is same. Simple first, complex after. This trend of starting with complex stuff like a F/A-18E or a Mig-23 is just conterproductive : you will get bored, depressed, lack of motivation and will never finish anything.
Beside that, if you can’t do texturing , that’s gonna be a problem. Maybe it’s not the time yet to start a 3D model, because no one will do the texture job for you, most of the time. Therefore, start to learn Photoshop, Fireworks or Gimp… They are the best candidates for this task. This will however take time. Paris wasn’t built in a day.
There can be share what are the key values to look all model the same standard. Such as the panel lines . their width and deep value on the displace or bump map .
This is step 85,632. First there is no such thing as “key value”, and we all have our styles. All the modelers quoted above have a different working styles. What counts is "how does it looks good for the eyes. For bump map, if you are already capable to make a 3D model, unwrap it and texture it, this is already great. For the rest, it’s always a “how does it looks good for the eyes”. For bump maps, there is various ways to get it. I use one method, some use another one… Everyone does like he or she wants, as long as it looks good to the eyes (and, as always, you need to experiment, test and re-test, because all models are different). With that said, be ready to export your model and check it ingame sometimes 100 times before getting a proper results. All 3D modelers are facing this kind of issue. This can’t be avoided, because all models (and real life represented material) are different, as already said several times.
Materials. there are the pType List but there are no information about the usage. example the cockpit glass. the F16 glass look excellent but the rest of the older model are not the same. why?
There can also use a common values of the materials , such as the glass, rubber, chrome parts. Make the look more same standard.
These are two topics. First is a BML v1 topic, second is a BML v2 topic.
For BML v1, easy, all is within @WaveyDave’s excellent post : https://forum.falcon-bms.com/topic/74/3ds-max-exporters-for-bms. There is a nice PDF document that tells all (Public/Falcon Tools/Exporter/Surface ptype settings) Of course this only works for 3Dsmax. You can just play with opacity and diffuse color level in 3DSMAX. Nothing more.
For BML v2 (the only possiblity for Blender), just… Create your materials. @okayasugf did a wonderful job with our Sukhoi Su-17/22. Beside that… Just create ! There is a magic with 3D which is creation. Do not wait people to guide you ! All modelers, I repeat, all modeler use different workflows and standards. for example, there is almost nothing in common between @lazystone’s workflow and mine. We still achieve models and integrate them. This is again a false problem. Dare, try and enjoy !
Animation
The DOF . I never saw a complex modell how can dof, how can set up the motion limits. which dof can we use which part . how can we link together . there are the dof numbers, but without the knowledge to use they are meaning nothing.
As for the rest : test (I will never tell it enough, we all work like that). I remember, the first time I implemented a DOF, I just placed one, and experimented within OGLLOD with it. Not with a complex model, just simple cubes. We all do proofs of concept and R&D because all models are different and have different requirements.
Game integration
Which program can we use and how? how can we link together the different 3d parts to be one in the game.
As long as you created your BML… Just test it by replacing another model. I remember, I started my models by replacing roughly F-16 RNLAF by by stuff. Then I experimentated with it, and in the end, it worked quickly. For something cleaner, it will always be through theater makers or BMS team.
Again, stop this workflow logic. this doesn’t exist here. We are all different, we all have different workflows. Just create a BML with the exporter, place it in the parent folder you desire, and test it ingame.
To end, 3D modeling is like coding : this needs training, self education and a sense of daring. You can’t learn this in 3 days, this is not possible and not even desirable.
There is everything needed in this forum to make a model. Maybe not on Blender, because this 3D program is still not fully officially supported by BMS. One day, with God’s will…
For example, your Gripen. BMS rules are :
- Up to 500K triangles for LOD0
- 1 or 2 8K textures - Albedo, ARMW, Emission will be reduced to 4K for public - - release, Normals can stay 8K
- Draw calls - No more than 500 for the LOD0
Just do your Gripen within this constraint, and post your WIP pictures on this forum. People will tell you when something looks odd. that being said, you can do everything my yourself, by testing things, day after day with ingame tests. When something is not well understood, just do as I did : check F-16 models. They are perfect, because this is a F-16 sim. As long as you stupidly copy and paste what you see on BML viewer, it’s gonna be perfect. This is what I did I remember when I started (on OGLLOD) Any doubt ? Copy F-16. period. And it worked and you will understand the principle of the functionality (ARS door in my case).
About testing, and R&D, something to show you :
I did this (this is nothing final, and I will even redo everything from scratch in term of DOFing, because this was just roughly done), just to check how I will animate ly nozzles, and potential model issue (there is). This is what all modelers do : proof of concept, raw tests, just to check : “how will I do this”.
Radium