Translating PBR textures to P3D / FSX

roger-wilco-66

roger-wilco-66

Administrator
Staff member
Hi,

I've been designing a lot of 3d models lately and adapted a new workflow that detours to Quixel for texture design. It is a totally different approach from the classic texturing and can result in spectacular results. However, translating the textures back to FSX / P3D prove to be difficult. I have some success now and want to put that up for discussion, since I know that I'm not the only one here who experiments with that. I'm also still learning on the subtleties of specular and reflection mapping, I'm sure there a a lot of people who know more on that than me.

So here's what I have found:

Quixel exports five different kind maps, which partly have to be merged as follows:

albedo + AO map ----------------> merge in Photoshop, albedo as base layer and AO as second layer, set AO layer blend mode to multiply. Dial in the effect via opacity. -------> export as DDS, which will become the diffuse map with no alpha channel. Should be suffixed "_T" in the map name as per SDK.

specular + gloss map -----------> merge in DxtBmp. Specular is base, gloss map must be loaded in the alpha channel. In the material config, "Blend environment by specular alpha" must be set to "TRUE". Reflection and specular scale must be set to the right parameters (my main difficulty). Should be suffixed "_T_Specular" in the map name as per SDK.


normal map ---------------> Bump map, rather. A normal map is derived from the normals of a highly detailed model (hence the name) and imposed on a low poly counterpart to make it look detailed, in my book. Anyway, Quixel converts this to the directx format and does so all right. Should be suffixed "_T_Bump" in the map name as per SDK.


I made a quickie of a test rig in 3ds max that consists of three 1 sq-meter curved objects with a bump map showing rivets and a few other details. I chose glossy paint, natural aluminum and highly polished aluminum as materials, because they are the hardest to depict. The maps are in 4096sq size to get high detail and all the impurities that Quixel throws at them. The rig looks in Quixel like this, in the basic renderer:

material-test.jpg


In sim, in the moment during early morning because the reflections are still too bright (I'm not there yet), it looks like this (I did not alter the base textures except for mixing them as I described above), they are just as Quixel exported them):

material-test-in-sim.jpg



Another important thing I found is that you can not rely on what ModelconverterX depicts. I suspect that the lighting values in MCX and the sim are quite different.

I can bundle the test rig model and the texture maps for download if anyone wants to experiment himself.


Cheers,
Mark
 
To anyone who's interested,

I made an "aircraft" out of the paint rig for easy testing. Just drop it into the aircraft folder. Changes to the model / material / texture settings can be done in ModelconverterX and saved right on top of the active model in the sim. Hit the "r" button in the sim to reload the model. That's an immensely practical function for us devs :) No more time wasted waiting for the sim to reload.

The rig is made to work in slew mode, and can be turned with the rudder function to inspect the reflectiveness under different sun angles.

I also made four different outside views (each panel close up + the whole rig) in Chaseplane, but I don't know if the cam presets can be exchanged / shared. But that's easy to set up.

Get the model here:

https://drive.google.com/file/d/1WmxW-dAGDlv1H2gcm9wZY91smcRIGKn3/view


Cheers,
Mark
 
Hi Mark,

sounds great, but I can´t see the pictures in first threat...

Cheers
Thomas
 
Hi,

For my actual project I will try to use Substance Painter (Quixel's competitor) which is (my own opinion) more efficient than Quixel: it's a standalone programm and not a plugin.
Have some of you tried this program and if so how did they work on textures to get them under FSX or P3D ?

Thanks for your replies.
 
The reason why I chose Quixel was that it has a native P3D export mode for the textures (which are directx materials in essence). However, this is not so easy and the Quixel devs are definitely in need of refining their export method. The other reason I chose it was because of NDo, which is a seperate package within the suite and is an awesome tool for generating bump maps.

With much fiddling around I managed to get good representations of the pbr renderer images into the sim, but I found that this cannot be achieved without changing the textures that Quixel is exporting. The problem is that there is no standard in regards to the FSX/P3D material settings and there are too many variables and ways to achieve a certain material look. So for each different material type there are unique ways at how the material settings need to be set for the sim.

I wonder how substance painter is working in that regard. The export function for the pbr materials is the show stopper in my point of view.

Another thing, running Quixel as a plugin for photoshop is quite beneficial, because it is very easy to customize the maps (e.g. decals, weathering, etc) as you are already working in Photoshop in a layered paint kit so to speak.


Just my 2ct :)

Cheers,
Mark
 
roger-wilco-66 said:
The problem is that there is no standard in regards to the FSX/P3D material settings and there are too many variables and ways to achieve a certain material look. So for each different material type there are unique ways at how the material settings need to be set for the sim.
Click to expand...

Soooooo true! :banghead:
 
Hi,

Thanks Mark for your answer.

I have tried Quixel and Substance Painter and in my own opinion I find SP more adapted in terms of ergonomics to my use.
In addition I found a developer named "Javier Rollon" who via his Youtube channel is explaining step by step the creation of an SIA Marchetti SF-260 for X-plane 11 (3DS) and the creation of textures with SP. It's a very good example in order to learn about this subject.
Of course, X-Plane is not FSX/P3D, but all of Javier's videos are very didactic and his experience is interesting.
During the last month, I have been browsing a lot of websites about Substance Painter to see how to adapt the results of the various export presets to FSX/P3D.
Indeed, it is not simple because SP is dedicated to creating PBR textures and the result depends on a large number of variables. That said, I hope in finding a solution to adapt/combine the exported textures for DirectX usage in order to create textures for FSX/P3D use.

If I find some result, I will expose it in this post :encouragement:
Best regards.
 
Has anyone had problems getting the exporter to export all the maps?
I've been playing around with a gun sight that has two nodes and for some reason it'll export all the maps in DDS format for node1, but only the albedo for node2.
I can get all the maps if I use the 'unprocessed PBR' export option which may be helpful...
 
My bad, guys, I just saw your replies.

@ lagaffe: thanks for the tip, I'll check Rollons videos!

@Skippy: The problem with Quixel, as I see it, is that

- it exports a set of textures that are diffuse, (albedo), AO (if you use it), specular and gloss map. Problem is where to put the gloss map, you can either use spec alpha or diff alpha for it.
- We don't have baseline material parameter settings for these maps.

I had some pretty good results exporting Quixel maps to the sim, however, they vary wildly for different materials (e.g. polished aluminum, glossy paint, faded paint, etc). In the end I always kept fiddling with the gloss and the spec map and adjusted material parameters to make it look good, and ruined finding that baseline by doing so.

As I see it, what we need is:

- albedo (diffuse) with a diff alpha that controls the reflections
- specular with spec alpha which controls the specular focus
- AO map which has to be overlayed (burned) on the diffuse (albedo) map

So there are _four_ native FSX/P3D material maps that Quixel should export, not three. And we need a baseline setting for the accompanying material parameters, otherwise we'll go nuts with individually adjusting that stuff. But I think that you always have that parameter problem regarding diff and spec alpha, regardless of which software generates them.

I hope my stammering makes some sense :)

Cheers,
Mark

PS Photo below is from a Lau rocket launcher from the A-26K, textured in Quixel:

lau3-ls22-2.jpg
 
You must log in or register to reply here.
Back
Top