Hi,
Is there a set of rendering parameters from a rendering/lighting perspective that I should be aware of and constantly check while working on lighting in Unreal? I believe EV100 is one of them. I want to make sure the lighting we are creating is as physically correct as possible.
Specifically, we are working on a night scene, and because the skybox is quite dark, the shadows are also very dark. Artistically, we are brightening them by increasing the skylight intensity parameter, but this is not physically correct is for example skylight intensity is 11. So we are balancing between an artistic look and a physically correct approach
.
Apart from the EV100 parameter related to lighting and rendering, is there anything else I should be monitoring regularly to ensure the lighting is correct, and that the values inside the engine going into the renderer are more or less accurate?
Thanks!
Hello,
Thank you for reaching out.
You can implement lighting setups that balance between real-world lighting units and artistic requirements.
Here are some UDN tickets with discussions about real-life units for Lumen and related pipeline best practices to start with.
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Please let us know if this helps.
So, basically, lighting in Unreal is a balance between technically correct setup and artistic choices - that is for sure. The question is how far we can push a physically correct setup without running into issues like pitch-black shadows at night from a gameplay perspective. For example, if the skybox (SkyAtmosphere) is dark at night, shadows naturally become almost pitch black.
To avoid completely black shadows, I’ve had to “cheat” the physically correct setup - for instance, by increasing the Skylight intensity above 1 or the sky luminance factor above 1. This is where the physically correct setup starts to break down.
My question is: Does Unreal have any tools to measure physically correct lighting, apart from EV100, which essentially checks how correctly the surface is being lit? Is there anything else that can help me to debug how far I am from physically cortect lighting?
Hello,
Thank you for the follow up.
In order to achieve your desired visuals with “how far you can push a physically correct setup” would require experimentation with changes to materials setups, lighting adjustments and post process settings adjustments like Color Grading and Tone Mapping.
Eye adaptation visualizer is useful for analyzing lighting values. In the Level Editor it is under Show -> Visualize -> HDR (Eye Adaption)
Please take a look at the Physical Lighting Units documentation for General Considerations, Tips and Suggestions sections for additional information.
https://dev.epicgames.com/documentation/en\-us/unreal\-engine/using\-physical\-lighting\-units\-in\-unreal\-engine?application\_version\=5\.6\#generalconsiderations
Please let us know if this helps.