MSFS [Improved] Custom Vegetation - Shadowed Faces

[Rotornut44]

Hello,
Has anyone been successful in making custom vegetation for MSFS yet? I'm trying to bring some vegetation models over from FSX, but I'm running into an issue with faces being shadowed in MSFS. Since my vegetation is made up of simple planes, it doesn't blend well with its surroundings.

The PBR preview in Model Converter X displays the vegetation just fine, however when I view it in MSFS, it's as if assume vertical normals is ignored.

Any ideas?

 

[GaryGB]

Hi Chris:

Perhaps a comparison of your FSX 'Grass' 3D models and a MSFS-2020 default object viewed in MCX Material Editor may prove informative ?

MSFS-2020 Packages > Official > OneStore > fs-base > scenery > Global > Asobo_Vegetation.BGL > MCX > Material Editor > [Properties] tab

ex: Grass_Kit01 - { d6123327-15c8-4368-9868-6337fabf3ce7 }

For this MSFS-2020 3D model, 'Assume Vertical Normal' is indeed set to "FALSE".

GaryGB

 

[Rotornut44]

Thanks for the idea, @GaryGB . I matched the texture settings to that of one of the MSFS veg models, but the issue is still there.

However, I do see that the normals for the MSFS models are vertical. When I choose to view normals for my model, they are pointing outwards from the face.

So, this looks to support my assume vertical normal theory. It looks like they have set their normals to be vertical from the start and the SDK doesn't recognize the "Assume Vertical Normal" setting.

As I have never had to do this, always relying on assume vertical normal, how would one go about changing the normals to be vertical?? I haven't found any info on it.

 

[GaryGB]

Hi Chris:

AFAIK, flipped geometry around the vertical axis is due to a new axes configuration in glTF versus a legacy 3D world axes model used by MS-FS:

https://www.google.com/search?clien...hUKEwjyh7P79KjuAhWDK80KHSP-BDkQ4dUDCAw&uact=5


However, Vitus states that the Normal Maps configuration follows the DirectX "industry standard" ?

"Normal map shenanigans
Normal maps for MSFS follow the industry standard. When you create normal maps, make sure to use the directX format and don’t do the old-school “red-in-alpha”."

https://www.fsdeveloper.com/forum/threads/primer-to-3d-asset-creation-for-msfs.448401/post-851045


Perhaps this thread addresses what you are seeing with lighting issues related to normals ?

https://www.fsdeveloper.com/forum/threads/creating-normal-map.449087/

If you are baking your normal maps in blender, you need to know that it uses OpenGL instead of DirectX. That means that the green channel from the normal map should be inverted to obtain the desired results in the sim (I am guessing MSFS is using DirectX). If normal maps are baked in blender, go to render options and under the "Bake" menu you can find "Influence", this is where you select the type of space (tangent, object, etc.) you want to use for your normal maps and under that you will find "Swizzle R, G, B". For the "G" (green channel) use "-Y" instead of "Y", that will invert your green channel and convert your normal map to DirectX. That's the quick fix but your normal maps will look totally wrong (inverted) in Blender because it is using OpenGL to display them in your viewport.

Anther thread raising questions with regard to MSFS-2020 Normal orientation:

https://forums.flightsimulator.com/...normal-maps-in-msfs-blender-workflow/310992/4


GaryGB

 

[Rotornut44]

Gary,
I believe this is a different issue then what I'm running into. What I'm running into really isn't an issue. The face normals are displaying how they (normally ) should. I'm not converting back from a glTF, but starting from a P3Dv4.4 MDL file each time.

When I open the vegetation bgl with MCX, I see that the grass (And a few other) models have vertical normals, instead of pointing directly out of the face, like on my model.

I think I just need to figure out how to point my normals vertical.

Edit:
I found this post, which describes exactly what I need to do, however, I have tried the two listed methods across 3 versions of blender and the normals refuse to change. What a pain.

How to edit normal direction

I am trying to point the face normals to another direction than the face is facing. I want the face to be about 45 degrees and the normal pointing straight up. But no matter what I use, normal edit...

blender.stackexchange.com

 

[Rotornut44]

I decided to raise the question to Arno, and created a new post in the MCX section.

As of today's Model Converter X development release, Assume Vertical Normal = True, when exporting to glTF will automatically set the normals of the model to vertical.

Now, the issue with being unable to disable shadows for objects is still there. Unfortunately, this just seems to be an issue with the MSFS SDK itself. However, now that the normal issue is sorted out, the vegetation already looks a lot better! There is still some shadowing on the faces, but it looks a lot more natural now and doesn't stick out nearly as much.

I'll mark this one as "Improved" as the shadows are still there, but the vegetation does share the same characteristics of the default. So, it at least looks uniform.