Race condition whilst cooking material layers: Invalid DDC key

Rendering - Oct 5, 2018

When cooking the DDC key for a material layers parameter set may become invalid which causes issues reading/writing to the global material shader map and can lead to a crash. See original UDN post f ...

Foliage Lightmaps Are Incorrect When Using a Precomputed Lighting Scenario

Rendering - Oct 2, 2018

Foliage lightmaps will not match properly to the lighting when using a lighting scenario. They will look normal if you select the Foliage tool but in PIE they will still be incorrect. Working as ex ...

Translucent Materials Receiving Incorrect Shadows in Forward Shading

Rendering - Oct 2, 2018

Translucent Materials will receive incorrect shadows in forward shading. This is working as expected in 4.18 CL# 3832480 Found in 4.19 CL# 4033788, 4.20 CL# 4369336, 4.21 CL# 4408769, 4.22 CL# 4413 ...

"Start Previewing Node" Does Not Work For Post Process Materials

Rendering - Oct 1, 2018

Using "start previewing node" in a post process material does not work. The preview will only show the final result that is connected to the material attributes.  Working as expected in 4.18 CL# 38 ...

Static Mesh 's Light Map Coordinate Index set to 4 and execute a light build, the result will be incorrect.

Rendering - Oct 1, 2018

Light Map Resolution is set to a small value (4 or 8), it will build normally. ...

Web Browser UMG Widget Does Not Work in DX12

Rendering - Sep 28, 2018

The Web Browser UMG Widget does not work in DX12. Found in 4.20 CL# 4369336 and 4.21 CL# 4404204 ...

MSAA Causes Black Outline with Atmospheric Fog in Forward Shading

Rendering - Sep 28, 2018

MSAA causes black aliased outline with Atmospheric Fog with Forward Shading enabled. This does not occur with TAA or FXAA. Also does not occur if there is a sky sphere present. Found in 4.19 CL# 40 ...

HLOD visibility state isn't cleared when changing scene

Rendering - Sep 25, 2018

HLOD state is not cleared when moving to a scene without HLOD so primitives may read the state from the old scene and incorrectly cull objects. The safe fix is to clear the HLOD state maps when the ...

Post Process Volume Priority Doesn't Affect Post Process Materials

Rendering - Sep 17, 2018

Post process volume priority doesn't affect post process materials. Found in 4.19 CL# 4033788, 4.20 CL# 4302132, and 4.21 CL# 4369303 ...