Hello friends, does someone knows what cause this problem?
Part of my landscape is black and there is two materials bugged. I have seven materias, and 2 of them causes the same problem: a section becomes black When I paint above. Aparently nothing is wrong, my materials are correctly connected, I tryed to mount everything again.
Is there a solution for this problem? maybe erasing this area and painting again with another layer.
Thanks!
There might be too many texture samples, judging by that screenshot. Mind posting a picture of your material?
I’m having a similar problem with fewer samples. I did find some threads on this about making sure the mats are compiled. Mine are and it doesn’t make a difference.
http://i.imgur.com/XXPujCfm.jpg
http://i.imgur.com/ERm5q6pm.png
to become easier, I mounted using 2 landscape cords, 2 for the color channel, and 2 for the normal channel, the error still persists.
Well I am almost decided to erase this material and do everything again, waiting a bit more for some response that could change my mind 
This seemed to fix it for me: Painted Over Landscape Blend -- Why Do I Get This Blackish Texture? (picture) - Rendering - Epic Developer Community Forums
Though I do think that’s a little unhelpful as a common solution. At some point I want to automate with height/slope and then paint to touch up. I don’t want to have to clear the automation before I can paint…
Well, this seem having nothing to do with my own problem, I will not delete the material, but will do another and keep the older saved as alternative. I will have classes of UNREAL and maybe someone could help.
All I have to do is thank you all for care about my problem.
Take a look here: .unrealengine.com/latest/INT/Engine/Landscape/QuickStart/4/index.html and follow the steps to the next page, which troubleshoots black/incorrectly painted materials.
Thank you again, The problem described also happened to my project, my base color was dark, then tryed to paint all my landscape and the dark disappeared, probably because there was no data on the layer. Now the problem is different, even after painting, that sector still remains grey.
Well my friends, the problem is fixed 
To achieve this task I simply created another material containing layers with the same names as the olders (grass, soil, rock, sand and plus another grassDARK), When I did it, the grey area disappeared, and all the painting I did before were there! I lost nothing. Glad that I did not need to do everything from begining.
Accidentaly I discovered how to solve it
There’s a simple solution to this if you use material functions.
Thanks, I’ll read up on those. 
It’s not gonna be easy to find the exact solution that I was given; the only reason I know how to do it is because an engine dev told me. I can lay out the steps for you if you want, so just let me know.
Any help would be appreciated. I’ve gone through most of the UE4 youtube videos. None of which are on landscapes, unless I missed them for some reason, and the non-official videos seem to demonstrate basic painting. That’s good and informative but I’d like to automate a good base and then paint for added detail.
I took a quick look at mat functions, seems a little like inheritance of sorts. Just wrap up some functionality as a node?
Alright I’m about to start on a video series that goes over the pipeline from World Machine to UE4, which includes how to do some terrain creation and then goes over some advanced materials for the landscape, which includes what you need.
Sounds excellent. Would be very helpful and much appreciated.
