What causes the shading/lighting problems I'm seeing in this screenshot

anonymous_user_125fc27f · September 18, 2015, 10:47am

Can someone suggest what I am doing incorrectly in the modelling/mapping/importing of objects that causes the issues inside the red circles in this screen shot? I have no overlapping UV’s I am letting UE generate the light maps. I had this as one whole FBX to start with but I have now broken it into all separate objects. I’m sure its something simple.

Jacky · September 18, 2015, 10:53am

Try increasing the lightmap resolution of these walls and build the lights again. 256 should do.

anonymous_user_125fc27f · September 18, 2015, 1:10pm

upping the light map rez did fix it on the walls. after introducing another object it appears again and light map rez of 256 doesn’t fix it. I am also having trouble selecting the destination or source index for ligthmap in the mesh editor details panel. if I try to pick one Ive created myself and apply changes it just jumps back to the original settings. then one of the indexes disappears?? every introduced mesh seems to create its own set of issues.

Jacky · September 18, 2015, 1:19pm

That one may be overlapping UV’s or the lightmap res. of 256 may not be enough depending on the size of that mesh.

I’m not sure whats up with the index problem. Can you share some screenshots please?

anonymous_user_125fc27f · September 19, 2015, 7:31am

Here is a shot of the posts with their problems and also their UV’s. The light map resolution does not seem to help here. Do those red lines shooting out of the UV map mean anything?? I will try and capture and explain the index swapping dilemma after I can get it to happen again. It only seems to happen when I create my own light map and also leave UE to create a set of its own.
I’m thinking the shading issues are all to do with my modelling/unwrapping techniques…or lack there of.

Jacky · September 19, 2015, 8:04am

Red lines mean there are faces out of the acceptable UV space(brown wooden part of the railing), which causes overlapping. And there are other parts that are sitting on top of each other as well. You can go back to your modeling program and pack those UV’s so that they are all in that square 0-1 UV space, or let UE4 generate UV’s based on that channel 0 UV’s.

anonymous_user_125fc27f · September 19, 2015, 8:15am

Ok… so as I suspected I’m missing a lot in the process before I even get to the engine… I will go back and re adjust UV’s and read up some more on light maps. How do I let UE generate its own UV’s from UV index 0 ??

Jacky · September 19, 2015, 9:07am

Here is an overview of UV stuff in the static mesh editor:

UV Channel drop down menu in red square lets you see the existing UV layouts, and it does not set the active UV channel for lightmaps.
Green dots lets you select the source UV channel to generate new UV’s based on. 0 is usually 1 in modeling programs and 1 is 2, etc. Once you set those and click apply changes it generates new UV’s. It works fine for simple geometry and/or if your source UV layout is ok but just needs to be packed. In your case Apply Changes button is greyed out, that means you had already generated lightmap UV’s during import(this option exists in import dialogue box as well)
Yellow dots is the last section you need to set for lightmaps, which we have talked about already in the previous posts.

So, select UV channel 1 and see if there are any red lines or overlapping surfaces, since you had already generated lightmap UV’s. If not then you should be good to go.

anonymous_user_125fc27f · September 19, 2015, 9:25am

Ahhh…I completely misinterpreted what the source light map index was. There was no disappearing index I was seeing the generated Light map from my selected UV’s. Also I was changing the min light map resolution not the light map resolution in the static mesh settings. AND Why is the light map coord index selection way down there??? I missed that completely… Thanks a lot your help has prevented a bunch of head banging the desk. Lots to learn !!