Changes to RectLight in UE5?

zombie420

In UE4, I feel like the RectLight would emit light evenly across the bounds of the source width and height? Un UE5, it looks like the light's source emits outward from the origin of the light. Is this intentional? Maybe a button I can toggle to swap functionality?

poopipe

in 4.25/4.26 they cast shadows from the origin in the same way. 
What happened before that I can't say, 

In ue5 with lumen you should be able to use an object with an emissive material for this sort of light 

zombie420

@poopipe

If I'm understanding it right, in 4.26 (with RTX) I'm seeing the light span evenly across the light source's parameters:


In 5.0 (with lumen) I'm seeing light emit from the actor's origin:


And testing with lumen, I'm only seeing emissives light up an area if the emissives are visible. Which is still cool, but doesn't help me when so much of the lighting is back light

poopipe

ive not been working with RTX on 4.26 so that might be it. 

you would probably get better results from lumen if you allow enough space for the light to bounce off the wall .  I've not  mucked around with it since the  first ue5 preview but offscreen emissive objects contributed to bounce light perfectly fine in that - it's still in development though, totally normal for stuff to get broken

ZacD

Also for lumen to work with offscreen emissives, you need to make sure all (most) of your meshes have distance fields enabled and built. There's still some issues if the emissive is too small.