LightScenario building places shadows to the wrong level

[c4tnt]

Hi. I’ve baked a set of light scenarios (special case of streaming levels) to simulate a day\night cycle with lightmaps and got a problem with shadowmaps. First lighting scenario contains a sun directional light, second contains some point lights.

When I enable world geometry and only first scenario there is no shadows from the sun except culled surfaces

When I enable world geometry with the second scenario it looks okay

And finally, when I enable both scenarios I think I found missing shadows from the first scenario.

There is no other lights except shown in the level. Also I tried to add one more lighting scenario with a different sun placement and it worked fine.

[c4tnt]

Things getting worse - only the last lighting scenario visible while building have correct shadows.

[anonymous_user_6e7b421a]

Hey c4tnt,

Could you provide me with a list of steps to reproduce this issue on my end? The setup for lighting scenarios should be pretty straight forward, but there are some slightly tricky aspects to getting them to work properly so let me know if you are getting confused when writing out your steps.

Cheers,

[c4tnt]

It seems light scenarios have only problems with BSP.

1. Make a little ‘persistant level’ using BSP brushes

2. Add two empty sublevels ant toggle them to the light scenario mode

3. Add a directional light (stationary) to the first one

4. Add three point lights (stationary) to the second one

5. Build lightmaps with all sublevels are visible

6. Check the result - all baked shadows are visible only when last built level is enabled.

[anonymous_user_6e7b421a]

I believe you are missing a few important steps about lighting scenarios that the attached test project should clarify. You do not want to build all your lightmaps with all the sublevels visible. You want to individually build these separate from one another.

When a Lighting Scenario level is present, lightmap data from all sublevels will be placed inside it so that only the DayScenario lightmaps are loaded when it’s daytime. As a result, lightmaps will no longer be streamed by sublevel. This means have a persistent level with the default lighting. Create a sublevel as a lighting scenario, and build that alone with it being the only visible sublevel under the persistent (also should be visible).

I have attached a test project for you to experiment with, to better understand how Lighting Scenarios are meant to be setup. Let me know if you have further questions or need additional assistance.

Cheers,

[c4tnt]

Sorry, but there is no BSP brushes here. As I tested and wrote in the comments light scenarios work fine with static meshes (even without hiding layers - in 4.15 it is good to build them at once)

I modified your project to show what’s wrong with BSP

You can get it here https://yadi.sk/d/KZ2gYLLX3GNGmh

[Added] It is possible to build one light scenario with BSP by hiding all other scenarios, but when trying to build next scenario you’ll lost all previously builded shadows.

[anonymous_user_6e7b421a]

So I did some digging and found the issue has already been reported.

UE-38027

Once the issue has been addressed by our engineers the ticket will be updated and reflected in the public tracker. Let me know if you have further questions or need additional assistance.

Cheers,