Composure FG and CG layers not working properly in Unreal 5.6

[WEFSflipfactory]

I have been going nuts testing this the last couple days and have determined that Unreal 5.6 can’t create proper working Foreground and CG matte garbage layers. We have a virtual production project and we are unable to make a garbage matte to extend our virtual set.

I did a ton of testing and took screenshots and was going to make a long post with many pics showing it all but im going to just simplify it to an easily replicated test.

Basically your tutorial on your site works in 5.3 but not in 5.6:

Real-Time Compositing Quick Start for Unreal Engine | Unreal Engine 5.6...

You can do this in 5.3 and it all works fine. But if you try in 5.6 only the background and mediaplate will work. When you connect the FG layer node in the material then your livecomp output will only show the FG layer. And if you create a CG Matte for a garbage layer then that will not work either.

Now the interesting part is that you can take the project from 5.3 and load it into 5.6 and it works! but you can’t create it from scratch in 5.6. So this tells me 5.6 isn’t really “broken” but there is some sort of setting or checkbox somewhere that is preventing it from working. I actually even tried copying the config folder from the working 5.6 project into the broken 5.6 project but that had no effect. I have searched around online. I know the older version had an experimental setting for the alpha post processing that is enabled and supposed to be built into the current version and that is enabled. i have messed with the epic texture setting and tried disabling anti-aliasing but those didn’t really have any effect.

So here is the really easy way to test and show this issue by just making a CG matte.

load Unreal 5.3
load VP template
create cine camera and move it back so you can see the scene
add a cube
make cube a layer
create composure comp
add cg matte layer
capture actor and include the cube layer

Now the cg matte shows you a white background with a black cube in it.

Do this exact same thing in Unreal 5.6 and the cg matte will just be solid white and not show the cube actor.

Now of course i can then load that 5.3 project into 5.6 and it will work.

If anyone knows what setting is causing this problem then please let me know.

Thanks!

[WEFSflipfactory]

After another day of testing I finally figured out the problem myself. Turns out that some lighting or atmosphere or volumetric effects can make the matte and FG layers not work.

The project scene we had purchased had something called “atmospheric fog” and when I shy that then the FG layer and CG matte work properly.

The default Unreal 5.6 Virtual Production template project that is not working has 2 items called SkyAtmosphere and VolumetricCloud that effect the FG and CG layers. They appear in the FG layer and cause the CG matte to turn solid white.

When you create the Virtual Production template in Unreal 5.3 It does not have those items in the outliner and that is why it works.

At least we have solved this mystery and maybe this post will help anyone else that runs into the same problem.

Thanks

Chuck

[WEFSflipfactory]

The forum wont let me post more than one pic, here is the screenshot of unreal 5.6 when i shy those layers: