MSFS glass problems

[kancur]

Hi! I have a problem where glass that is further away is overdrawing the one closer to the camera. Unfortunately, using different draw orders is not possible here, because the glasses can be viewed from both sides. I also tried different glass occluding situations and it's behaving super weirdly.

I'm doing all the work in blender.

So today I tested it with some simpler non-textured glass materials and here are the observations:

And when I move the camera slightly it starts to look like this:

I absolutely don't understand why.

Is there anything I'm doing fundamentally wrong? Do you have any tips for me? Thank you!

 

[kancur]

Trying to make some magic using multiple planes with opposite normals and draw orders, unfortunately the only two results are these:

The rear one overdrawing the front one.

The front one completely overdrawing the rear one (instead of drawing on top of it)

Is something like I'm trying to accomplish even possible?

 

[Anthony31]

What are your material settings and setup?

Here's a quick model I just made which seems to be working for me (excuse the very rough textures).

The glass texture is a PNG with transparency. The texture settings are MSFS standard material with Alpha mode in the Render Parameters set to Blend. Double sided material is off, the interior and exterior windows are separate faces. In the Settings tab the Blend Mode is also set to Alpha Blend and Backface Culling is ticked.

 

[kancur]

Thanks for the reply! I too use a png with an alpha channel. I tried to use the standard MSFS material instead of the glass. It looks better for sure, but still the lines in the back are overdrawing the front ones, which I believe might be the case in your screenshot as well, it's just hard to spot.

Notice the shadowed lines in the back overdrawing the front glass. Regarding the faces, I have the same setup as you.

The bad thing is that you lose that beautiful glass effect of reflecting the environment which comes with the glass material.

MSFS glass material (transparent, yet reflective - just like glass should be):

MSFS standard with high metallic and low roughness values, with alpha mode set to opaque (looks like a mirror, just as it should):

And this is the same material (high metalness, low roughness) but with alpha mode set to blend. Unfortunately, all the reflections are gone. That's why using the standard MSFS material is not the way to go I believe.

 

[kancur]

I tried simplifying it and testing it without any texture at all. However, the same still occurs, the closer glass is getting overdrawn by the one further away - Even if I don't use any texture, just vanilla material with some settings. What I tried right now, is using two materials, each with different draw order:

1. This camera facing face has a material with a low draw order.
2. This camera facing face has a separate material with a higher draw order.

This finally renders correctly. I should be able to do the same to the opposite side looking faces to make it work. However, it's super cumbersome.

@Anthony31 What happens if you try to use the MSFS glass material instead of the MSFS standard? Can you please post some screenshots of that? Thank you!

 

[Anthony31]

I think draw order is the way to go. My early model fell apart when I looked at it from the other side. I've been doing some testing myself and I could only get consistent drawing in the correct order with the draw order parameter.

For a simple walkway you only need to make the outside glass have a higher draw order than the inside. But if you start lining walkways up side by side it all falls apart as you will have outside glass being drawn over outside glass again. If you have a series of walkways it may be necessary to have separate draw orders for each walkway which really will get cumbersome.

I had earlier discounted MSFS Glass because it puts a reflection of a generic cockpit on it by default. Which is stupid for scenery. You need to turn Reflection Mask Factor down to zero to get rid of the cockpit reflections.

I also had a hard time figuring out exactly how Glass likes to be setup. In the end Albedo colour close to white and near maximum (or maximum) transparency seems to be the right mix otherwise it all appears rather opaque.

 

[chongwen20110901]

I have the same problem earlier when I was trying to model my terminal. The glass looked better for me after the recent MSFS update. I guess it's just some render glitch?

 

[kancur]

Unfortunately, the draw order trick doesn't work with all glass objects - which you can view from all sides.

 

[Anthony31]

So I've had to deal with the glass problem myself now. The attached picture shows the issue. A curved windshield.

The initial plan was to have the exterior surface of the windshield set to MSFS_Windshield and double sided so you can see rain drops from both sides. The interior surface would be set to MSFS_Glass to get nice reflections of the interior. Having both materials visible inside the cockpit would provide some depth to the windshield (you can see the inside and outside surfaces of glass).

I am fairly convinced that using double sided material is a big problem for curved surfaces like this as it caused no end of graphics glitches where the back surface was drawing in front of the front surface.

In the end, after much tinkering, I came up with this solution. The exterior surface points outwards and is single sided only and set the MSFS_Windshield. This surface was then duplicated and the normals flipped so they point inwards. This allows the rain drops to be seen from the inside. Finally, the inside surface of the windshield is set the MSFS_Glass to provide the reflections of the cockpit interior.

No double sided materials were used.

As a final step I named the parts in an order that puts the exterior surface pointing inwards first (Cockpit_window03), interior surface second (Cockpit_window04) and exterior surface pointing outwards last (Cockpit_window05). I have no idea if putting parts in alphabetical order affects the draw order but I did it anyway. Note that the 3 textures used for the windshield all have Draw order 0.

As far as I can tell this seems to work for my aircraft.

Final point, If using the Blender exporter check to make sure that your export options have Include - Custom Properties ticked to make sure it exports the MSFS materials code. At some point I had this unticked and I'm not sure what effect that had.

Very final point. I'm not sure if this will be the final format I use. While the cockpit reflections of the glass material are nice I am finding the material itself somewhat difficult to work with as it creates a very dark texture plus there are numerous artifacts in the reflections that aren't pretty. Changing the direction of the eyepoint also tends to affect the reflections. Something for me to worry about in the future.

 

[Lagaffe]

Hi,

Concernning rain effects, I think I read on discord that it was necessary to use a cube with MSFS Environment Occluder material to display the rain?
Have you had any information about this type of material and do you experiment it?

Ref: https://discord.com/channels/766957329232166933/766957481275424768

On the screen, the cube seems to be IN the VC ...

 

[Anthony31]

Hi,

Concernning rain effects, I think I read on discord that it was necessary to use a cube with MSFS Environment Occluder material to display the rain?
Have you had any information about this type of material and do you experiment it?

Ref: https://discord.com/channels/766957329232166933/766957481275424768

On the screen, the cube seems to be IN the VC ...

Just selecting Windshield material and mapping it as recommended in the SDK works. Look at Aircraft Texture Mapping in the SDK. It shows the direction you need to map the windshield texture to get the rain to flow in the right direction.

I don't even know what this means:

EnvironmentOccluder​

This material will be used to hide environmental meshes that eventaully compenetrate with a mesh with this material assigned.

 

[Lagaffe]

This information was present on the discord of NewkTV and it is associated to Discus development (follow my link).

 

[614NLV]

I don't even know what this means:

EnvironmentOccluder​

I always add a EO-cube to my objects
otherwise it rains inside

 

[Lagaffe]

Ok, I better understand in this acception and after that it seems logical.

 

[Anthony31]

I always add a EO-cube to my objects
otherwise it rains inside

Thanks, I see what you mean now. My aircraft has an open cockpit so I guess I never noticed the rain being inside the cockpit because that's where the rain should be in an open cockpit plane. Just looking at my plane now in the rain I can see rain drops falling between the windscreen and eyepoint so it would seem like you would need to make an Environment Occluder object to keep it out of your cockpit if it was enclosed.

I took some screenshots but they didn't really come out well so there's no point in posting them.

I don't think the Environment Occluder and the Windshield materials would affect each other. The Environment Occluder should affect the moving rain drops (more like dashes) and the splashes on the ground. The Windshield material would still draw as that is a different type of effect. For example the moving rain drops do not actually hit the windshield and have a rain drop form at that location. One thing I need to do is remap my windshield as the rain drops are too small. If I reduce the area in the UV map I expect it to make the rain drops a bit larger.

To sum up and answer Lagaffe's question, the rain appears without the Environment Occluded. It seems like you will need to create an Environment Occluder object to prevent rain drops appearing inside the cockpit.

 

[614NLV]

right 👍
I add that this EO prevents all atmospheric conditions, not just the rain.
even the fog, the humidity and the others.
I have not checked the wind but logically I would say yes, the wind too

 

[Christian Bahr]

I add that this EO prevents all atmospheric conditions, not just the rain.
even the fog, the humidity and the others.
I have not checked the wind but logically I would say yes, the wind too

Environment Occluder Material also works great in grass and snowfall:



This may open up some new possibilities. Here you get the best tips! 👍👍👍

 

[lionheart]

As a final step I named the parts in an order that puts the exterior surface pointing inwards first (Cockpit_window03), interior surface second (Cockpit_window04) and exterior surface pointing outwards last (Cockpit_window05). I have no idea if putting parts in alphabetical order affects the draw order but I did it anyway. Note that the 3 textures used for the windshield all have Draw order 0.


View attachment 66173

Genius! Very nice work, by the way.

Where is the adjustment for Draw Order located in Blender?

 

[lionheart]

I was noticing snow coming into my plane. This explains it. No occluder (yet).

 

[Anthony31]

Genius! Very nice work, by the way.

Where is the adjustment for Draw Order located in Blender?

Draw Order is somewhere in the MSFS materials section that the MSFS2Blender plugin adds so it's not a Blender parameter, it's an MSFS parameter. I'm not at the PC at the moment but I think it only shows up for some material types (such as glass and windscreen) and not for others.