Directional light does not illuminate anything unless movable

I’m trying to illuminate a landscape with a directional light, but as soon as I build the lighting after I’ve added a directional light, it goes completely dark. I’m not getting any errors, and I do have a lightmass importance volume covering the entire landscape. However, nothing is illuminated regardless of the intensity of the directional light.

Also, I’ve noticed that if I make the light movable instead of static or stationary, it actually does light up. But I don’t want it to be movable, I want it to be either static or stationary. When I do that though, everything is as mentioned dark.

Does anyone have any idea why this might be?

Hey Mars-

One quick thing to test right off the bat is to make sure that you do not have Force No Precomputed Lighting Checked to true in your World Settings >> Lightmass. If that does not solve the problem could you upload a screenshot of your lighting setup, lightmass world settings, and the two versions of the lit and unlit level you describe above.

Thank You

Eric Ketchum

It was already unchecked, so here are those screenshots.

Lit level, when directional light is movable:

http://puu.sh/ckGp4/56bd1ec488.jpg

Same level, with light set to static/stationary:

http://puu.sh/ckGnm/786f5cc291.jpg

Directional light settings:

http://puu.sh/ckGuc/a7c029fea0.png

http://puu.sh/ckGv2/730944f584.png

http://puu.sh/ckGwk/13c7f16dc1.png

Lightmass world settings:

http://puu.sh/ckGym/ac81a163c8.png

Hey Mars-

Ok I think I have an idea of what settings to change. First go into the World Settings under Lightmass>>Lightmass Settings and change the Environment Color from Black to a lighter color, my suggestion would be the color of you Directional Light specifically if it is supposed to represent the moon. If that color seems too bright, try using shades of blue with mid level saturation and play with the value until you get something you like.

Next and probably most importantly, up the value of your Directional Light from 0.05 while this setting may work for a Movable Light which is dynamic it may be too low to be transferred to the rendered lightmaps.

You also may want to consider adding a Skylight to the level that does not Cast Shadows which will enhance the effect of your environment color as well.

It’s a balancing act between the settings above to get the result you are looking for.

Let me know if after experimenting with the above settings you still cannot get the results you are looking for.

Thank You

Eric Ketchum

That gave a quite weird effect. My directional light was static for all of my tests.

With the lightmass environment color set to a darker shade of blue, and the directional light set to zero intensity:
http://puu.sh/cloYK/c27977dfb1.jpg

Same environment color, but 20 intensity on directional light:

http://puu.sh/clp9G/b06c81b4f2.jpg

In other words, changing the environment color paints the entire landscape uniformly in that color, and the directional light does nothing at all. Apart from changing the environment color and the intensity of the directional light, all settings are as I had them in the previous screenshots.

Hey Mars-

If your landscape is a Static Mesh what is the Lightmap resolution and do you have a second UV Channel unwrap setup in your Static Mesh Editor? If it is a landscape component what is the lighting resolution set to?

Thank You

Eric Ketchum

It’s a landscape component made by the in-editor sculpting tools. The static lighting resolution, under the “lighting” category, is set to 1.0.

Hey Mars-

Try setting the Static Lighting Resolution to 4. Does the Static / Stationary Directional Light build any different?

Eric Ketchum