I’m increasingly frustrated by lighting in UE, where everything seems to be a cheat.
I have a scene with some objects needing reflection, so I put the Sphere Reflection Captures in it, and they completely change the lighting of the scene. I’ve been through the documentation from Epic, and I’m still in a fog.
why do they appear to add substantial light?
How does scale effect them?
Brightness: should this just be how bright the captured sample is?
How much overlap between sphere is acceptable?
Is there a falloff between the center point or its scale and the total radius?
Your help is appreciated.
Top Image with Sphere Reflection Capture, Bottom without:
This depends on what is being reflected and how reflective the material is that is influenced by the reflection captuer.
How does scale effect them?
Scale determines the area that the captured reflection will affect. It’s best to keep these smaller to be more accurate. As the documentation shows, you can use multiple sphere reflection capture to get better results.
Brightness: should this just be how bright the captured sample is?
You can adjust the brightness scale for the captured image when you select it and adjust the property in the details panel.
How much overlap between sphere is acceptable?
You can overlap them and there will be a blend between the two. Since the reflection capture is just a six sided image (cubemap) that is captured and applied to the reflection sphere.
In this image below you can see the two I have in the scene. The one on the right has a smaller radius and will blend with the other but you can see where the radius stops the image is more curved (red line).
Depending on your scene and how reflective it is, this may or may not matter in some areas.
Is there a falloff between the center point or its scale and the total radius?
No falloff. It’s just a cubemap image applied to a sphere for reflections. Ideally you would use rougher surfaces or if you need really reflective surfaces you would use a combination of SSR and Reflection captures to tweak the look. It’s best to have a slight roughness to hide some of the more obvious artifacts that can be caused by either SSR and/or Reflection Captures.
These three pieces of documentation/examples should cover the basic ins and outs of using Reflection captures.
