I've noticed that not all my omni lights flicker -- only the ones that I've cloned from the faulty light. I figured out that if you ever explore the flicker settings, that omni light will be permanently messed up.

Deleting all my lights and re-adding them seemed to resolve the issue.

Never mind. It was my imagination. Light are still flickering like crazy.

There's a limit on the total number of per-pixel direct lights being rendered at any one time.

Reducing the 'End Fade Dist' will lower the maximum distance the per-pixel lighting will be rendered from - beyond that distance, the light will simply switch off and not contribute to the light count. (If you navigate around the recent TF2 Supervillain Lair and pay close attention, you'll see some of the spotlights switching off when seen from a high enough distance, along with props fading out in order to help performance.)

Another trick is to set the 'Direct Lighting' to 'Baked' instead of 'Per-Pixel'; this will put the direct component into the ambient vertex lighting and will become effectively free to render. You will lose direct specular effects, and more contrasty lighting can show artifacting on low-poly world meshes. Rebuild the lighting with 'Baked Lighting: Bake All Lighting' to see how it looks. (Make sure 'Shadows : Cast Shadows' is enabled for baked omni lights!)

For performance reasons, make sure you restrict the radius of per-pixel light sources as much as you can. Having many lights affecting the same surfaces isn't great for maintaining good framerates (again, this is irrelevant with baked lights). Also, don't have too many shadowed spotlights - shadowmaps are rendered to a single large texture of fixed size, which can be visualised in Hammer with 'vr_shadows_debug 1' in the console. (Switch it off again with 'vr_shadows_debug 0'.)

There's a bit more on a basic lighting setup here if you need it: https://developer.valvesoftware.com/wiki/SteamVR/Environments/Environment_Tutorial:_Hammer_and_Basic_Lighting#Basic_Lighting

For a larger map, baking light may take some time. To speed things up, make sure you limit the volume that needs high-quality lighting with a light_importance_volume entity (set the extents in a similar way to a env_combined_light_probe_volume) otherwise it'll use the maximum extent of the map geometry as its limits. If it's trying to fire billions of photons around the place, you've probably done something wrong...

I hope that's of some use! I typed a bit more than I initially intended...

Thank you for such a detailed reply! Also, thanks for writing your original lighting guide. It helped me a ton getting started. I'm so tired, but I'm tempted to try all your advice right away :D

Lets see... 1 Directional / 2 Spot / 39 Omni / 0 Ortho / 42 Total

Oh... Could my room full of candles be a problem! I set them all to bake (I'll miss the pulse effect, but oh well). Time to sleep now -- I'll check it in the morning after the 433.5M photons bounce around my light_importance_volume.

Yup -- all fixed. Baking the candle lights and limiting the 'End Fade Dist' did the trick. Thanks a ton!

Check it out if you have some spare time

Nice! Remember to add teleport meshes and teleport points at some point - and perhaps some rope bridges etc. to connect all the floating islands together?

Re: flickering lights - you should be able to get away with a couple placed in strategic locations. A low intensity fill-light or a conveniently positioned spotlight - so long as things *feel* believable, you can get away with a surprising amount...

I actually prefer the "organic" nature of unrestricted teleportation to anywhere that supports collisions. Half the fun for me is exploring without boundaries, even looking through meshes that you shouldn't.

This map is a work in progress, but I'm going to add rocks that float up (upon puzzle completion) which connect each island more easily. Thanks for checking it out! Did you fire the cannons? That's by far my favorite part so far.

I'm totally stuck on ropes. They look to be unsuppported at the moment. I was going to try to make some ropes out of the particle system, but I'm not that skilled with it yet.

I'm getting off topic :D I could chat about this all day. Thanks so much for all the amazing work.

Also, good point about adding a single flickering light. I'll put one on the fireplace!