Hi there! I looked everywhere on documentations, forums and answers, but can’t resolve my simple stupid issue
Trying to get my awsome customizeable RPG character to alive I got a noticeable seams on lighting between joint skeletal meshes (pls take a look on the picture, you can see seams between body-to-chest and chest-to-legs parts). Compare multi-part dude (at left) with a single-mesh dude (at right).
I studied all the documentation about lightings including lighting troubleshooting, tried to use two-side shadow casting, working around with world settings and lightmass setting, created physic-assets for every skeletal part - no results.
Please, if someone can point me out where to put attention to solve this issue on multi-part skeletal? Thank you per advance!
Thank you Achilleon for pointing me in right direction, the problem really lies on the side of 3D-application (Blender in my case) and it’s transforming of vertex normals while splitting the mesh on several parts. Unfortunally I can’t find a proper way to fix normals in Blender, so after several hours I came with a horrible work around for multi-part characters:
Make your hi-poly character;
Make a copy of hi-poly and transfer it to low-poly mesh;
Split your low-poly into several meshes you want. At this point you’ll notice ugly seams between them;
4)Select all separated low-poly parts and simply join them into one mesh (Ctrl+J in Blender)
Bake Normal Map for this ugly low-poly mesh from your nice smooth hi-poly character.
Split back your low-poly mesh into parts and use baked normal map to hide seams between separated parts.
Doing this with new Normal Map I came to the result you can see on the picture. They are the same dudes - multi-part and a sigle-mesh, but due to new tricky Normal Map they have inversed the appearence of seams.
Unfortunately I can’t be any of assistance if it’s not 3ds max. What is the reason for having multi-part mesh anyway? Maybe we can figure out something else incase someone that worked with Blender does not help you.
After surfing through internet around generic approaches for customizable characters I found out that there is no an “out of box” solution. It’s up to character designe to how you would like to change its appearence. If you want to use a singl-mesh character and simply add for example a jacket mesh → you have to take care about every single frame in every possible animation to be sure that character’s skin doesn’t shows up through jacket on shoulders and elbows. If you want to use multi-part character and replace “naked chest mesh” by “jacket chest mesh” → you should take care about how to deal with vertex seams :-/ I choosea multi-part approche cause I can’t struggle anymore with animations.
Finally I ended up with a bit different approach from my previous comment: I took a regular high-poly normal map, but in order to leave all vertex normals on the seam untouched I cutted mu dude’s neck one loop below the seam loop and scaled that cut loop a bit down so this extra loop was hidden by the chest mesh. To create the chest mesh I cutted the neck on the loop above the seam loop, and again scaled cut loop a bit down. As the final result, dude’s head mesh is penetrating a bit inside the chest below the seam, and the chest is penetrating inside the head mesh above the seam, which is actually bringing a quite acceptable result regarding the lighting
I’ll post some description pics a bit later.
Personally I found this work around quite usefull cause it not depends on 3D application you’re using → they all use vertex normals the same way. Well… latest version of Blender DOES has normals manipulation tool, but it’s still too rough and lack of control.
Hey! Here is how I solved it in Blender, without horrible work arounds:
I used a Data Transfer Modifier to transfer the Custom Normals data from the body to the head mesh. I’ve limited the modifier to a vertex group, that is only the boundary edges of the head mesh.
Normals before and after:
Hey, I was able to make the seams disappear in blender using the data transfer modifier, but when I export the fbx into unreal, there’s still a seam like before. I tried applying the modifier but it doesn’t help.
Did you have this problem?
For anyone who has it looking good in blender, but as soon as you import to UE the seams are back. make sure you have your Normal Import Method in Import Settings set to “import normals and tangents”. (they are set to calculate normals by default) Then reimport your meshes.
