How to disable post processing for unlit sky sphere

Hi all,

I really need some help getting my scene setup that uses an ‘unlit’ sky sphere for an otherwise lit scene. I can’t imagine i’m the only one experiencing this problem, however I haven’t been able to find a solution on the answer hub that doesn’t include adding extra instructions to the sky sphere materials (which I wouldn’t think should/would be necessary)


The problem that I am encountering is that the Background Texture/Materials always appear washed out when I run with scene lighting enabled.

As you can see from the picture below, the camera / scene settings are identical in the image below, with the only difference being the left side is ‘unlit’ and the right side is ‘lit’. The lit version has lost a significant amount of the details to the textures.


My scene is setup as follows:

I have a huge sky sphere that has several settings disabled (listed below) and I have a directional light, ambient light, and a few point lights in the scene to provide lighting on my pawns and other actors.


The SkySphere Static Mesh is setup with the following settings:

  • Materials → (all 6) have cast shadows disabled
  • Collision → Collision Presets is set to ‘NoCollision’
  • Collision → Can Character Step Up On is set to ‘ECB No’
  • Lighting → Cast Shadow is ‘False’
  • Rendering → Render in Main Pass is ‘True’
  • Rendering → Treat as Background for Occlusion is ‘True’
  • Rendering → Receives Decals is ‘False’

The materials are setup as follows:

  • Physical Material → is ‘None’
  • Material → Shading Model is set to ‘Unlit’
  • Material → Two Sided is ‘True’
  • The Textures that are referenced have ‘Mip Level set to Absolute’
  • The image below shows the Material setup


If anyone knows how I can setup my scene as lit with an unlit sky sphere that does not appear washed out I would greatly appreciate it.

Thanks,
Mike C.

I am also running into this as well. posted here and I’ve got no response either. If I find anything out, I will be sure to post here. Please do the same, I am stuck.

Hey MCiccarone,

One way to control the brightness and contrast so your Skylight looks a bit more crisp, is to add a ‘Multiply’ and ‘Power’ node. I would create these as scalar parameters so you can quickly modify and see the changes as a Material Instance to find the correct values.

You can also try using a different Anti-Aliasing method other than Temporal AA, as this can sometimes blur images with the way it is calculated to reduce the stepping effect on images. Try switching to FXAA instead to see if that helps as well.

If you have other questions, let me know and I will do what I can to assist you.

Thanks,

Hey, buddy, You are genius! Thank you for helping, ive been running at the same issue.

I dont want to have to try and eyeball calibrate my textures manually, I want them to look the way they are intended to look. Why all of a sudden do unlit textures not look correct in ue4?

Yeah it’s pretty inconvenient because for example if you want to use a sky photo (for example converting down an HDRI) for the skydome, then you tune that image in Photoshop to the final outlook. But then it’s all washed out in UE, so you need to randomly guess and in Photoshop and oversature it to make it useful. But my biggest problem is that quite often it still won’t match the original.

I also ran to this, my solution was to go the Forward Renderer path with MSAA, it isn’t optimal cuz MSAA is very expensive but it balanced out with lightness of the Forward Renderer.

That’s a pretty big step to change the whole rendering path, just to get a decent looking unlit sky. I actually figured out a better workaround, which doesn’t solve the original issue, but helps to counter its effect. There is a node called DeriveHDRfromLDR in the material editor, with this you can get a much more vibrant and saturated outlook from the washed out mess that it was on default.