How to blend smoothly two meshes with different UV maps and shaders?

Question

Good day everybody!

I tried to look for the answer to my Q everywhere and tried few things, still can't understand how to do it. Will be grateful for your help.

To the things I've done:

1. I got a 3D head+neck model (with UV map, textures) that was exported from the game.
2. I need to merge the head to the body. So I created the right-shaped body with MB-Lab (and I'm not sure if it's the best choice 'cause of its different shading).
3. Next thing - I made just a simple mesh from this body (applyed all modifiers MB-Lab had created), deleted this body's head and somewhat mached the colors of the needed head and the body. But the MB-Lab body has more complex (different) shading mechanism than the head from the game.

Now to the problem:

I'm not sure if I have to to create one object from the head and the body (union the meshes/connect their edges) to make it work BUT the thing I need is to create smooth transition between those meshes(their textures). There are different UV maps, textures and different types of shading. Is it even real to do it with blender without complete unwrap or redrawing the textures? May be MB-Lab is not the best option for this (I needed to create realistic body for free)? Or what is the general way to do it properly?

If I need to change texture files (in Photoshop, for example) - I'm not sure how to match them exactly. Besides, MB-Lab modifications (nodes? like Vein amount) in Shading make the final rusult color different from it's original (base color) texture color. I tried CTRL+J and do something with MixRGB (mixing different UV maps with different textures), but it doesn't work properly in my case - the transition is not smooth, I can't match the same texture on the different meshes.

So, I need the transition to be smooth if the character wears only swimming trunks, for example.

I use blender 3, eevee.

Thanks for any help! Can provide the link to .blend if you can solve this problem.

Answer 1

Okay, I found the okay solution myself. My way of doing things will suit you if blender is your hobby and you just want to render images with characters from the game, for example. The final model also could be rigged and looks just fine. If you are an experienced blender user (or it’s your work) - you may find my ways of doing things offensive. I’ve warned you (=

Get a body with the simular shading as the head

Smooth, sacle, subdivide if needed and shape the body as you like (edit + sculpt)

Delete the head from the body, match the head and the body position, in edit mode change vertexes position so they may be connected later smoothly

Ctrl + J head and body. Connect the vertexes to get one mesh. Make transition between them as smoothly as you can. Sculpt if needed

Match specular and roughness in shading. Match colors by editing texture files. Create new UV map. Unwrap the part of neck and the body (the transition - new meshes - is in between). Scale the unwrapped items on the body-base-color texture (the neck-body part)

Create Vertex color - now paint the smooth transition. New meshes you created must be black, then black smoothly shades into gray and white.

In shader you need apply this thing to the head shading AND to the body shading: UV map node (select new map) goes into image (body texture), which goes into RGB mix shader. The other image that goes into RGB shader is your basic texture (body or head). Factor for RGB shader is Vertex color.

Basicaly, you use third texture (which is you body texture) to blend it with body and neck textures to create smooth transition. You may want to merge vertexes by distance and relax them (there’s addon for relaxing).

Copy the texture for the body and use it for the transition area insted of original in shading, so you can edit this copy image and fix seams (edit texture so seams aren’t visible).