Hello, all! My problem is that my brushes are not reflecting any light. I have a very bright sun in my map, but there's not a single bit of light on anywhere besides my character model and weapon. I do have Reflection Probes, a Light Grid, and a Sky Light Grid. When I walk past windows I see the shadow of the brushes on my character's arms, but I do not see any light on any portions of the map. Would I have to place separate nodes of light for every single part of the map?? Thanks in advance.

You need the actual "LIGHT" in order for it to be lit.
You can't just put a SkyBox with a sun and expect it to light up the map.

If you don't want to place light's individually around the map, place 1 big light at one end and one big light at the other end, lighting up the entire map.

Place lights, hit up the Entities window and increase range and density to your liking. Recommendation for most huge maps: Radius = 1500 - 2000
Density = 1.5 = 2.5

Now this is not really whats considered "Good Lighting" but it will at least light up your map and then later you can play around with it.

^ that could work, but...

if you are too lazy to light your map properly i would use ambient setting in worldspawn: kvps are ambient value: 0.2 - 1 are good values 1 being very bright and 0.2 being pretty dark but not too dark, also for reflections make sure u have specular maps enabled in the options menu

You need the actual "LIGHT" in order for it to be lit.
You can't just put a SkyBox with a sun and expect it to light up the map.

If you don't want to place light's individually around the map, place 1 big light at one end and one big light at the other end, lighting up the entire map.

Place lights, hit up the Entities window and increase range and density to your liking. Recommendation for most huge maps: Radius = 1500 - 2000
Density = 1.5 = 2.5

Now this is not really whats considered "Good Lighting" but it will at least light up your map and then later you can play around with it.

Thanks, man! Will work on it.