Triangle Shadows on Landscape


i have a question about the shadows , when i let my Sunlight (Directional light) be Movable (Dynamic light) , i’ll get triangle shadows somewhere on my landscape

like this picture :

does anyone know how can i fix this problem? , or the only way is to let that area more smoother?

The only thing you can do is to use a larger scale macro normal map that introduces larger details to the landscape. Mix that with the normal map you have now.
Think of a normal map that has shapes that are larger than the size of a single triangle of the landscape mesh. That should break up the form a bit so the triangles aren’t that noticeable.

Do what jonimake said, or if you don’t want to add that kind of roughness to the terrain, just throw some meshes on there to make the transition a little softer. Maybe some icy rocks or something.

you can make the scale of the landscape smaller and use the smooth brush on it.

Late to the party but in any case could be useful for someone. You have another option - you can change the lighting channel on the landscape to say 2 and have one dynamic light only shine on channel 2 and turning the cascading shadows maps cascading shadow distance to 0 - which causes the issue. You can then have another dynamic light in the same location that casts shadows normally on channel 0 or 1…

Both messing with lights and scaling down the landscape adversely affect performance.

The best solution is actually the normal map in terms of performance.

In terms of how things look. You could just put in a decal with a normal effect to break up the triangulation.

Similar effects are to-date still visible even in Fortnite.

I don’t think this is a CSM issue, I think this is a “very coarsely tesselated landscape with features that attempt to capture detail smaller than the tesselation” issue. Those stairsteps in the “edge” of the terrain tell me you will want at least 4x better resolution here, and if you really want “sharp cliff edges” then you should either use detail meshes, or align those edges with the grid of the terrain.