Shadows from objects/foilage on landscapes

Hi everyone,

I have a question that I can’t find an answer to.

Basically I imported a landscape which is about 3x3 km in diameter for an open world game. I created some foliage in Speed Tree and imported it in to the project. When I place a few trees as static to crate a forest they cast dynamic shadows on to the landscape with ‘ok’ quality, however when I build lights on the map the trees no longer cast shadows, there is just one black spot under them.

I did some testing, I opened the default first person example project, placed a tree there and built the lights, the shadow cast by the tree was good. At that point the floor of the level was a BSP cube about 40x40 meters in diameter. When I enlarge the floor to 1x1 kilometer for example and build lights the foliage shadows completely disappear.

I also noticed that changing the value in ‘Overridden Light Map Resolution’ of the floor the shadow quality cast by the tree goes up and down.

https://s21.postimg.org/9ffq8sp9v/Untitled.jpg

https://s18.postimg.org/nu15t1kw5/Untitled2.jpg

(The white boxes in the screenshots cast shadows because they are dynamic, the trees are static)

So what am I doing wrong? Do I have to set the ‘Overridden Light Map Resolution’ to something huge like 8192 to get good quality shadows on a big landscape? That will take for ever to build lights… Or is there some other settings that I need to change?

Thank you in advance. :o

Heya! This is definitely related to lightmap resolution.

You can set them per object either in the Static Mesh edtior window or the selected objects in your level. I would highly recommend to read this page about common lighting issues: https://wiki.unrealengine.com/LightingTroubleshootingGuide#Lightmap_Resolution_.2F_Shadow_Quality