Attempting to blend SkyLight Cubemaps via the SetCubemapBlend function to blend between different Cubemaps to make the changes seamless is not reflected.

As a workaround, in LumenTracingCommon.ush, replace GetSkyLightReflection with GetSkyLightReflectionSupportingBlend to apply the blend. This is also mentioned in the following thread.

Steps to Reproduce
  1. Download the repro project in additonal Info URL
  2. Open in editor
  3. Play in editor


When changing the value of InBlendFraction, only A or B is reflected and not blended.


When blending via the SetCubemapBlend function, A and B are blended according to the input InBlendFraction value.

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ComponentUE - Rendering Architecture
Affects Versions5.2
Target Fix5.4
Fix Commit28995810
CreatedOct 17, 2023
ResolvedOct 24, 2023
UpdatedOct 27, 2023
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