After building lighting, black splotches show on landscape

When Lightmass needs building, the landscape looks great - however as soon as I build, I get the effect seen in the attached image. This is not related to the material, as it happens when any material (or none at all) is applied.

I cannot figure out what the issue is. I have resized the lightmass importance volume, both to cover the whole landscape and only covering the player area - both produce the same results.

The landscape has been resized to fit the world, as it was too large, I’m unsure if this has caused the issue. If so, should I resize during creation or after creation?

An unrelated sub-question, but should I have the lightmass over the entire landscape or just the area a player can walk? It is possible for the player to see most of the landscape.

Thanks for the advice. I’ll try those out now and return with the results. Much appreciated.

Yes, you need the importance volume covering the whole area you want to build the lights for. For black areas, you should increase Static Lighting Resolution. Try 4 and keep increasing if it’s not enough. And build the lighting again of course.

I tried that, but sadly it it didn’t make a difference. It also took roughly an hour or two to build - which seemed overly long; I have a powerful computer and normally builds take, at most, 20 minutes.

If it helps, the landscape is a height map import from Geo Control 2 at 63x63 Quad Size, 2x2 Sections, 16x16 Components - Total Components: 256, Overall Resolution: 2017x2017

Build time increases a lot as lightmap res goes higher, especially for landscapes. Can you remove the material, set the lightmap res back to 1 and rebuild the lighting please?

Spent a lot of time attempting fixes so far. Sadly since it’s a lightmass issue, rebuilding after each change makes it take a long time to see whether or not it has been fixed.

I’ve reset all landscape settings to default (lightmass, LOD etc) and removed the material as requested. Here’s an image of all viewports, hope it helps.

Thank you for the continued support.

Hmm, well the only thing left to do is recreate the terrain in a new level and dont resize it this time. Set the lighting and the volume as usual and lets see what happens.

I recreated the terrain - didn’t touch a thing. Left the scale, rotation etc completely alone and there were only very small splotches in very hidden areas - but they could quite possibly be from using the lowest quality build setting.

I then created a new landscape for testing purposes; in which I only rotated the landscape, I didn’t scale it at all. Same splotches appeared that you can see in my early screen grabs.

I then did another test in which I created a landscape, scaled it to 200% and did not rotate it. Not a single problem. SO it appears to be a bug related to rotating the landscape.

Thank you for your help, and I hope my tests may help others.

Cool! Glad that you could spot the problem. :slight_smile: I don’t know if it is an expected behaviour of the landscape so you can post another report on this specific issue for Epic staff to see if you like.

Yeah, it doesn’t seem like it should happen. My game is an infinite runner style game, so I’ve set up all the blueprints to world space, meaning rotation of my character / lanes would totally mess up the blueprints, so I would hope to see a fix for being able to rotate landscapes!

Thanks for your help, it’s been really useful. Much appreciated :slight_smile:

Ha, I say that and now it’s doing it regardless of scale and rotation. Albeit, a lot less aggressive when no rotation is added.

This is an odd one. Had no issues with hand sculpted terrain.

EDIT: It appears my previous replies have disappeared?

I saw the notification of your last comment(the one before this one) in my mail. Maybe you deleted your solution post by mistake and then both our sub-comments got deleted as well?

Anyway, i’m starting to think this is a problem with the heightmap you imported. I can give you a heightmap to test if you like, let me know and i’ll upload it.

Edit: Saw that you posted here already but now there is an official answer on the effects of scaling and rotating a landscape:

Thanks - I actually haven’t deleted any comments or solutions, but oh well haha.

Thanks for all your help. Glad there is an official response.

I had a similar problem and none of the solutions I found solved it…
Then I made my landscape material 2 sided and the black splotches went away.