Dynamic Shadow from Stationary Point Light in Forward Renderer only partially visible after light bake

Before building light:

After building light:

Gif of behavior: 2017-09-05 16-10-43 GIF | Gfycat

This only occurs in 4.17 with the forward renderer enabled, tried in 4.15 and 4.16 but the shadow works properly in those versions. Steps to replicate:

  1. Create an empty 4.17 project
  2. Enable Forward Rendering
  3. Create a big static cube, smaller movable cube and stationary point light
  4. Bake lighting

I hope I’m missing some obvious new setting in 4.17, anybody got any idea how to fix this?

we’re seeing this too

Hello MXII,

After doing some digging I was able to find that this is a known issue. I have provided a link to the public tracker. Please feel free to use the link provided for future updates.

Link: Unreal Engine Issues and Bug Tracker (UE-48146)

Make it a great day

Pretty sure this edit to ShadowProjectionPixelShader.usf (at line 232, as of the 4.17 release in UE4-QA) fixes it:

	float4 HomogeneousWorldPosition = mul(float4(ScreenPosition.xy * SceneW, SceneW, 1), View.ScreenToWorld);    

becomes

	float4 HomogeneousWorldPosition = mul(float4(ScreenPosition.xy, SceneW, 1), View.ScreenToWorld);