Build Lighting issue

Development Rendering
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1

Hi,
I have a serious problem with the build light in UE 4.25
when I complete the light layout in the environment and want to build, after building the environment becomes dark and the lights lose their effects.
I have been working on this project since version 4.21. But I have just encountered this problem and everything I do does not change!
I send some pictures from Lightmass Settings, SkyLight, PostProcess and LightmassImportance. Tell me if the wrong settings cause this to happen.

alt text

322368-beforebuild.jpg
322368-beforebuild.jpg1912×936 371 KB

322369-lightmassimportance.jpg
322369-lightmassimportance.jpg590×666 75.1 KB

322371-postprocess.jpg
322371-postprocess.jpg598×1327 124 KB

2

A few aspects need to change, based on the settings posted:

  1. The Auto Exposure is set to darken the scene based on a pixel brightness of (0.8 - 1), or the Min/Max settings. Change those to a wider range (-2, 2 … -5, 10), or set them the same (0, 0 … 2, 2). The problem is the exposure adjusts to a certain lighting value, making the scene darker depending on the Min/Max settings. So, increasing the range won’t make it so the scene is easily darkened.

  2. This one is a potential problem. The Lightmass Importance Volume, in its Actor settings, is set to “Try to Adjust Location, Don’t Spawn If Still Colliding”. It’s most likely that volume is colliding with something in the level, so it’s not spawning and not getting used in the light bake to concentrate lighting to the area it surrounds. Change that settings to Ignore Collisions, or Still Spawn Even If Colliding, and see what happens.

  3. Increase Lightmass World settings for Bounces. Try Indirect Lighting Bounces 4-6, and Skylight Bounces 3-6. In addition, lower Fully Occluded Samples Fraction by up to 0.5, and reduce Indirect Illumination Occlusion Fraction by up to 0.5 too. Decreasing “Direct Illum Occlusion Frac” might help too…but not to 0. Finally, it’s probably best to disable “Compress Lightmaps”.

3

Thanks a lot dude!
I made all the changes but failed each time. Until I realized the amount of Light Map Resolution was too low for all objects!! This is really strange to me. Because in version 4.21 I did the build work without any problems!

Thanks again for your guidance :slight_smile:

4

Sorry it didn’t work. Lightmap resolution is one I missed. Do you know how to change the lightmap resolution of a number of objects at the same time? Select all the objects, then in the details panel enable Override Lightmap Resolution, and type in the new value.