Low Poly Landscape Rendering Strangely

I am trying to set up a very simple low poly landscape am getting weird results. Pictures will help explain it better than I can with words. I’ve highlighted the issues with red circles even though it’s pretty obvious.

Playing in editor:

Mesh editor (with UVs showing. Small square is underside of the landscape):

Playing in editor at night (light shines through previously black parts):

3ds max UV map:

A little more information if needed:
I’ve been playing with the UV map for the last couple hours because I thought that was the issue but I’m not convinced it is. I have tried with and without overlapping UVs with countless variations. I am very new with UV maps and could very well be doing it wrong.

For lighting I am using BP_Sky_Sphere with directional light.

The materials are very simple. Base color set to vector parameter and roughness at 1. I have tried selecting “used with landscape” but that doesn’t help.

How I made the landscape:
In 3ds max I created a box (20,000x20,000x1,000), selected all the square polys at the top and used connect with 1 segment and “100 slide” to make the surface made of triangles. I’m not sure if that is the best way of doing it or is even pertinent. If someone has a better way of “triangulating” square polygons I would love to hear.

Please help! This is driving me crazy!

Hell tehhax,

I have create a test in Maya to recreate what you are having an issue with.

I imported that landscape with a few verts moved into UE4 and built the lighting. I saw a very dark area displayed on certain points on the landscape. My first thought was to go and adjust the lightmap resolution. I changed this from it’s default 64 to 1024. This drastically amplified and sharpened the dark areas. Then I considered lowering the resolution to reflect the lower resolution of the landscape.

This did the trick.

These are screenshots of the result and where to change the lightmap resolution.

These are where the settings are inside of Static Mesh.

Hope this helps.

Thank you,

Hey thank you so much for the response and going through the effort of re-creating the issue!

I figured out the black spots were caused by something to do with the static mesh. I hadn’t tried rendering the mesh in 3ds max (like a dummy) and saw that the issue arose before the mesh even made it to UE4. I recreated a similar landscape using the same technique and had no issues. Something went wrong at some point when making the mesh in max. Black spots are gone!

I am still having the issue with the strange lighting at the base of hills and dips. I am using the light map resolution of 8 but that didn’t seem to do the trick.

Here is the issue at night:

Here it is in the mesh editor:

Here it is in a 3ds max render (not quite as obvious):

59131-3dsmax_lowpolylandscape_render.jpg

If it matters I made the hills/mountains with soft selection and just moved them around. I checked all of the Z values at the base of the extruded terrain and they are all the same. Since all the Z values are the same, they shouldn’t be casting shadows on each other, right? The issue appears in 3ds max as you can see above. I can go ask the autodesk forums if it’s better suited there.

Is it maybe something with the material? Still using just base color and roughness at 1.

Just letting you know I have found the solution! It was with my mesh. The method I used (connect edges with 100 sweep) was creating duplicate vertices that understandably confused UE4.

The solution was to select all the vertices in my landscape model and weld them (value of 0.001 worked fine). Lighting was instantly fixed after that.

Thank you so much for the help!