UE4 Unreal Raytrace Shadow in Reflections

Hi,

This post was raised as my friend was facing problem regarding reflection and its shadows,

Problems :

1. Reflective Objects were seen black in reflection.

2. Shadows from Skylight was not casting in reflection.

So We followed the following steps:

a. Enabled Ray Tracing by File->Edit->ProjectSettings

Just search for Ray Tracing and enable it and do the restart for the engine.

b. In the scene there was only skylight with this HDRI. So the reflections were good but the reflective object self was casting black reflection.

So we added PostProcessVolume and enabled the unbound for it so hat it would affect the whole scene rather the boundings.

We increased the Max. Bounces to 4 so that the reflective object can be seen with multiple bounce and no black spot should come.

c. So we got this , but we here saw that the shadows aren't seen coming from Skylight, so we enabled the Cast Raytrace Shadow for the same in Skylight.

d. But In Reflection there isn't shadows yet and we got the console command for the same as

r.RayTracing.Reflections.RayTraceSkyLightContribution=1

After this the reflection got shadows as expected but yes the reflection shadows are much much expensive than reflection itself.

Hope this would be helpful and informative but using shadows in reflection is much expensive.