not quite sure what your wanting.
the pic looks like it uses an additive/translucent unlit material for the walls/ceiling with a grid that was either applied using a texture or mathematically derived. not sure what ur talking about with the mat function layer blend as you can just ‘lerp’ or ‘if’ between blue and white.
the ceiling lights/blinds/heaters are an opaque unlit material with just a solid blue in the emmisive.
then a post process outline effect is applied so you can see the light/blinds/heaters.
the picture wouldn’t change much if the wall/ceiling was opaque, for example you can currently see through the ceiling and see the top of the light fixture and you just wouldn’t be able to see that.
Check out this tutorial, you should be able to easily modify this to get the look or are trying to get. Your blue would simply be a blue unlit material. If your entire scene is looking like this you could also look into doing a custom shader or post process effect.
This should get you that exact effect. If you want something like in the photo (squares) you would need to use a texture to make sure the lines are mapped correctly, this is because all meshes in UE4 are turned to triangles and no quads. If you want squares and are not concerned with the lines matching up to look like an accurate wire-frame, you could procedurally generate the lines in your material, create a material function that generates the lines and then use blend to add them to the base blue material.
I have tried all your suggestions but haven´t found an easy solution. So at the moment the work around is to duplicate the mesh and choose one with blue color and the other one with white wireframe. I was hoping to create one material that is drag and drop to the material slot and no more.
Wireframe material was the only one that could get correct lines. I haven´t tried Vertexpainting because my mesh is quit big.
Do you think a duplicated mesh with wireframe will affect my fps a lot?
If you are doing this effect for your whole level then yes, could be problematic. Not really any issue if you are using this effect to highlight a selectable object or a few objects. All depends on your scen and needs.
I tried setting up a materia lusing material layers, however there is no option for wireframe in a material function
I found this link which explains some various methods, but they are from simple texture map to advanced options: Wireframe material part1: The "not so manly" way - Community Content, Tools and Tutorials - Unreal Engine Forums
Thanks, that was an interesting link. For the moment I will go for two meshes one with a base color and one with wireframe. But this is something I would like to resolve in the future. Will get back to you if I succeed
