Why light icons are shown in red?

I have seen this asked other times with no answer.

I have a level with lights, reflection boxes, and decals. They are shown with icons in red. What does it means? Also I notice that the tranform input in the details of these objects appear in grey and unabled to be changed.

Perhaps something to do with changes in the asset paths? I have changed assets moving them from ne folder to other. The lights are created inside a blueprint, and the blueprint has been moved from one folder to another. That could explain the red icon, but reflection boxes? The aren’t inside any blueprint and show the same behaviour.

You can’t have more than 4 stationary overlapping lights.

From the docs:

Only 4 or fewer overlapping stationary
lights can have static shadowing,
because the lights must be assigned to
different channels of a shadowmap
texture. This is a graph coloring
problem, so there are often fewer than
4 overlapping allowed due to topology.
Shadowing cannot affect the overlap
test, so the sunlight typically
requires a channel from the entire
level it is in, even the underground
areas. Once the channel limit is
reached, additional stationary lights
will use whole scene dynamic shadows
at a severe performance cost. The
StationaryLightOverlap view mode can
be used to visualize the overlap,
which is updated dynamically as you
modify the lights. Light icons are
changed to a red X when they are not
able to allocate a channel.

Extra reading about light:

When something is transform locked, its sprite icon will turn red.
To lock transform on an actor, right click on it → Transform → Lock Actor Transform.
The sprite color may not update immediately. If so, save and reopen the level to see the change.

2 Likes

This worked for me. Thank you