Blender and PBR

#1
Hey all,

With the recent release of P3D v4.4, I've start to look into PBR. I've looked at YouTube videos about it and talked with some scenery developers in our field, but all of this is useless if there's no way to apply it through Blender - after all, I don't have a budget for any sort of paid 3D modeling software. Now, the current Blender2P3D plugin has the option to add specular maps, but PBR would then also require a glossiness map to go along with the specular and diffuse maps (or metallic, roughness and base color maps, in different terms), but I don't see a way to assign this map in the Materials interface. Many YouTube videos that I have watched about using PBR in Blender actually use Cycles Render, not the default Blender Render, but this is not an option for use with Blender2P3D.

So, my question: in its current iteration, can the Blender2P3D plugin be used to assign PBR materials, or is an (extensive?) update to the plugin required that enables the use of these materials? If we can do it, then what's the way to do it?

Thanks,
Benjamin
 

n4gix

Resource contributor
#2
The PBR implementation for P3D required L-M to add an entirely new Material Editor section as an alternative to the regular FSX/P3D Material Editor. IOW, until someone such as Arno manage to decode the new PBR Material editor's syntax, any update for Blender will not be possible.
 
#3
Hi Bill, thanks for your answer!

That's what I suspected... I was reading over the PBR chapter in the SDK docs and I noticed that there was a new implementation of the material editor. It did occur to me that instead of doing these things through Blender and the Blender plugin, probably you would be able to do it through MCX, whenever this might get updated to include such features. As such, it seems that right now using 3ds Max is the only way to get to work with these features, correct?

Thankfully, AutoCAD has educational versions for free, so while I'll still do all the modeling in Blender, I'll probably try to export them to 3ds Max and see if I can get a handle on PBR implementation in P3D. At least that way I'll get some idea of what this is all about.
 

Pyscen

Resource contributor
#4
Hello..

The plugin for Blender... will not save the additional needed slots for PBR materials. I'm not sure though, but Blender 2.79b, may have the slots... I need to look into it myself. Just so there isn't any confusion, Arno isn't the creator of the Blender plug-in for FS. Though certain formats of models within Blender can be converted into MCX (but not as yet for PBR materials).
 
#5
Thanks for your answer Doug. 2.79b does not have the slots; this is the version I've been using. To use PBR in Blender, one has to use Cycles Render, and use the Principled node to which one can connect all the relevant maps for the PBVR effect. But, as you probably know, the plugin only works with Blender Render and not Cycles Render, so this is sadly not an option. Indeed, the last one to work on the Blender plugin is Manochvarma. I hope he has the opportunity to update the plugin for use with PBR in Blender, or, better yet, for use with Cycles Render. I read somewhere that Blender 2.8 will lose Blender Render entirely, so if the plugin is to survive and make use of new features in Blender, a jump to Cycles will be required :S
 

Pyscen

Resource contributor
#6
Hello...

Actually,... You are correct that the Plug-in will save only within Blender Render (BR) and not Cycles Render (CR), but there are functions within CR that can be used and saved or "applied" before switching back to BR [such as some of the modifiers and map creations, such as AO maps. The map creations that are created can be edited within Blender or outside of Blender, but at this time, have to be save externally to be manipulated to be a part of the FS world]. Given this,... some "variables" could be saved from CR to BR (theortically, whether the PBR Material slots can be transferred over or saved is maybe a possibility).

You are also correct that the Blender Render will be or has been dropped in the upcoming version 2.80 (already in Beta Testing as we speak - expected to come out of beta testing early next year). Supposedly though, there are parts of the Blender Render that has been made a part to Eevee (the new Cycles Render Engine). The new plug-in section or instructions are being worked on as we speak as well. So, its a matter of a waiting game. I am not expecting that the new Cycles Render (Eevee) will function with the Blender Plugin (Blender2FSXP3D) for FS at all.

I'm sure once the documentation for Plug-ins is released, we will have a better idea what needs to be done or if it is even possible (doesn't mean though it will be easy or even possible with Blender 2.80). The current version maybe all that we have to work with; Blender Foundation has always kept previous versions available.
 
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#7
Thanks for the insight, that’s very interesting. I didn’t know that aspects of CR can be carried over to BR, is there anything specific that you use this approach with?

Either way it sounds like significant work will be needed to maintain compatibility with new versions of Blender. But as long as the toolset dan be made to work with the evolution of P3D itself, that would be all we can ask for, I think
 

Pyscen

Resource contributor
#8
Hello...

Well,... Specifically this approach is used in the UV-Mapping etc... it is handled through the CR much easier in doing so... then you can edit the textures through your photo editor or even through Blender. The creations of AO Maps etc are created as such as well. Previous to version P3D v4.4, AO Maps could /can be used providing that that are blended or layered into a Diffuse Maps. UV-Mapping can handle all of the material maps required or needed - its a matter of combining them or layering them (for versions prior to P3Dv4.4).

The only difference between CR and BR is how the information is stored. The UV-mapping is kept across the 2 different renders,... its just a matter of saving the different maps within their particular slots.
 
#9
I've always did it the way you describe: UV map, bake the AO, then blend it into the diffuse map in Photoshop. I bake the AO maps using BR actually, is it better to do it with CR? I see your point: the UV map is always there and is independent from the rendering engine. However, it seems like BR does not offer a way to store the metallic and roughness maps, so that would be the limitation, I guess...
 
#12
The fact that the FSX exporter is set up to work with Blender render materials only is not that important in practice. To bake the textures you are much better off in Cycles. My practice is to model and export from Blender 2.79 using Blender in BR mode. But I put a second version of the model into Cycles for texture creation and create new materials there for that purpose. I am now using Blender 2.80 beta for this and have no choice in fact as I just discovered 2.79 doesn't support my new video card for rendering. You can have as many versions of Blender installed as you like. Just don't use the installer as it may wipe out your older versions.

Using PBR materials in Blender is completely different from PBR materials/textures in P3D. For the latter, all you will be doing is putting a label of sorts on the material or texture. I am sure in time the exporter will be tweaked to do that.
 

Pyscen

Resource contributor
#13
Hello...

You could always have multiple versions of Blender - providing the usual installer is not used. Basically, a copy and paste (or dump). I know there are a few that aren't comfortable in doing that though.

The CR may take longer on rendering on some computers but you also have better control on the sampling (better resolution in the end)... How or what names are used has always been a bother. Even for Microsoft, such as Normal maps to Bump maps ( though the latter does go through a converted state) - The detail map is another example. How the names are done isn't the problem though... considering that Blender has gone through a major overhaul - it will take time to convert the plugin - What I'm afraid will happen is that there will be 2 versions of the Plugin again, 1 for FSX to P3Dv4.3 (Blender 2.79b) and another for P3Dv4.4 (Blender v2.80).
 
#14
Heh. I always assumed that because the plugin worked with one renderer, there was no point in using the other one. I understand now that you can bake the textures and make new materials in CR, that can then also be used in BR, correct? As long as the texture is baked first in CR... Or is it so that the materials you make in CR are used to bake textures, and then you set up new materials in BR using those CR-baked textures?

Also, thanks for the link Didier!
 
#15
You can make materials in Cycles to generate textures. You can then convert these to DDS to using in FSX/P3D and assign these textures to your materials in BR from which you will export your model. You won't be bringing your Cycles materials to BR; you use different materials in BR with the various FSX material settings that are used for export to .mdl format. If the only rendering you are doing is to generate an ambient occlusion map, then maybe BR is all you need. But if you want to bake with a full lighting setup, create textures for shiny metal parts in the VC, create wear and tear on the textures, etc, then you are much better off using Cycles for those tasks.
 
#16
Aah, I see. I can see myself baking lights as well; in fact I think I may have already had a stab at that on an earlier model. Overall I was going to predominantly use dynamic lights, but inside the terminal building and areas further away from the airport I won't want to use the dynamic lights. Thanks for the recommendation Michael, much appreciated!
 
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