Lightmass 'Light Source Angle' not working on UE4 & no 'Self Shadow only' option?

In Unreal Engine 3 you can go to Lightmass-> Light Source Angle and change the value to make shadows “blurrier” (affect penumbra size). Editing this will not force you to recompile the level’s lighting.

In Unreal Engine 4 you do the same, and the level’s lighting will need to be recompiled and no effect is visible upon changing the parameter (tried increasing from 0.4 to 4).

I cannot find anyone else writing about this which makes me wonder if I’m doing something wrong… (I’m using a Stationary light).


In UE3 we had a ‘Self shadow only’ option available… is their any way to do that in UE4? (It doesn’t appear as a lighting option for static meshes).


Light Source Angle can’t change value

In UE4 You have Light Source Angle(4.5 patch). I Knew it is in Light Source but I can’t active it is grey title there and can’t change value.

Light source angle does not work with regular stationary shadows. These work similar to the dominant directional light shadows in UE3 which also did not support adjusting the light source angle.

It does however work with static shadows as well as the new sphere-traced distance field shadows, which is why the setting is also available in UE4.

“Only self-shadowing” is not a available in UE4 as it is very inefficient to achieve in a deferred renderer.

Ok, my point is to make this shadow more blured, less detailed, softer. How can we make it blured with static or stationary light (Static shadows on UDK was so cool).

I was just checking it in the editor and it seems like there’s a bug in 4.6. That option should be available for static lights. At least it was in previous builds.

Here’s a quick test in an older version (4.2 to be exact) of the expected behaviour:

I would recommend you test the 4.7 preview. If the light source angle is also not available for static lights in that version I would file a bug report on AnswerHub.

Mark this as bug. I wonder how to make this working.

This is correct. Note that Area shadows are listed under ‘Features for Static Lights Only’ on

I want to make level with static light only and it is looks like this option is turned off.

A little more exploration of the issue seems to indicate that the feature still works properly, but that recent editor versions simply do not properly enable the input field when switching a light to static. I posted a bug report with some more details on the answerhub here: