blender model materials got messed up during import

two screenshots…

Has nothing to do with that. Its in the materials themselves. Unity has updated things and Smears textures. I wasn’t having any issues til their recent updates. This is a case of someone not considering this and assuming it “must be a mistake done in blender.”

What is being assumed is when you made the model and applied the textures in Blender, that while in Edit you did not use the Unwrap while having the whole object selected, or added another UV layer, etc. and then dragged object into Unity.

They are not considering the fact that Unity during one of their “needless Fixes” while focusing on one element of “latest new bells and whistles” forgot to make certain some of thew most basic elements of the engine were still working correctly.

Ultimately the problem is indeed which version of Unity you are using and which one has the problem with the materials conversion upon import from Blender into Unity or from Blender, to the Desktop, to Unity.

You are going to have to play around a bit to figure out which version wont mess up that you can use and make certain to check your models in a preview “material view” in Blender next to the option for Object, Editing, Sculpting, etc. That white little ball, and put it in Material view.

For example if you are using a square shape texture, you will use while in edit mode for Shading/UVS the Unwrap and go to the part that says Cube Unwrap. In any case if it looks the way you want in Blender and goes to hell in Unity, you can bet its the way Unity is reading the Material or the Texture or a combination of Both.

Second is also being assumed without getting more information that you simply duplicated another part of the structure causing a transparency problem in Unity as a mistake in Blender.
This happens a lot on Blender’s part. But its a simple fix.

Again you can have all that Backface culling checked and whatever, but its in Material view that will show you if one of the faces is “transparent” where in while having that duplicate highlighted, under the same “Shading/UVS” tab you use Flip Direction and not “Recalculate” as Recalculate often does more damage than anything.

If you already know how to apply a texture onto a material and assign it to the mesh itself, then you know that is also the area you scroll down to and will find a setting by default set to UV, under that MAP and under that Projection. That is the area on Blender being talked about. This is NOT a feature in Unity. At least as I have seen in the Personal version for Indie projects. I don’t know what the deal it in the “leased or paid version.”

Move your directional light and apply a suitable shader to the material.

I’ve recently faced a similar issue with materials in 5.3.1. Unity was messing up the material ID indices; we had to manually tweak every affected model (basically reassign same materials to different meshes). No biggie, but still annoying knowing that we’ve prepared a neat export.

Might as well fix them yourself in the editor, you won’t die.

Cheers!