This seems to be a new thing since the jump from 4.16 to 4.20. I’ve looked for similar things and bugfixes but no joy.
I have a blueprint for a ceiling light, with spotlight down and pointlight to create a lit area above the lampshade:
(this is an old BP and the settings and mesh may suck, but whatever)
I put the lampshade blueprint on a very basic interior mesh like this, with a wasteful but essentially reasonable lightmap (and lightmap size of 256 so this isn’t a lightmap resolution issue):
I’ve put this in a lightmap importance volume, and do a high quality light build:
The area above the lampshade is lit as intended (ish), but there are lots of lit areas where there shouldn’t be lit areas. At least one splodge appears to mirror the lighting above the lampshade. There is a large indirect lighting scale (3.8 or so I think) but otherwise nothing unusual about the pointlight so far as I can see. All of the ceiling lighting is static. (There is a stationary sunlight and skylight.)
Setting the pointlight to not visible (in the BP) does not affect the lighting error. Setting the intensity to 0 removes it, however (though of course the lighting is not complete):
Replacing each of the components of the BP with normal meshes and lights produces normal lighting.
So… what’s up here? Is this a 4.20 bug? Or am I doing something stupid? This is a really old BP so do I need to remake it?
Thanks in advance for your help. Copy of this test level available on request (will zip it up and upload it somewhere if I have time).
