Light estimate intensity conversion!

Include the following details (edit as applicable):

  • Issue category: Rendering
  • Device type & OS version: iPhone 13 Pro with iOS 17.0.3
  • Host machine & OS version: MacBook Pro 16in 2021, Ventura 13.5.2
  • Issue Environment : On Device
  • Xcode version: 15.0
  • ARDK version: 2.5.2
  • Unity version: 2021.3.14f1

Description of the issue:

Hello! I was wondering if there’s a way to convert the light intensity units which is in lumens to the Unity URP light intensity unit. I’m trying to update the directional light in scene to match the ambient light for more realism. The thing is, the lumen intensity i grab from Lightship light estimate is in the 1000s easily which is waaaay too bright for Unity’s directional light!

In the image below the intensity is 1028 and too bright for the scene.

And second question: Is there any way to get the light source direction estimate? For possibly re-positioning my directional light to align with the real-world ambient light.

Thank you!

Hi Alvin,

The Unity forums had a discussion about the conversion of Unity intensity units to some SI units here:

It doesn’t look like they came to a perfect solution but there are some proposed workarounds in there.

Tracing light back to its origin sounds even trickier. In some conditions, you’ll be able to detect shadows and that will give you a clue but Lightship does not yet provide a tool for that purpose.

Please keep us posted on this thread with solutions you find or any other questions that come up. Thank you