Normally when I get this issue, it's either because:

1) The prefab is using multiple materials, and clothing prefabs can only use one material. So, some parts of the model will appear invisible. In this case, you will need to combine all the materials into one by joining the textures of the different materials.

2) Some issue with the model itself. I always make sure that I've applied all the model transforms in Blender and that its origin is snapped to the World Origin. (Ctrl+A Apply > All Transforms). I actually don't know if this serves any purpose, but for consistency alone it's a good idea.

I'm pretty much a newbie using Blender and Unity, so there might another reason..

Does it look right in the Unity Model Preview Window?

引用自 SweetCaptn：

Normally when I get this issue, it's either because:

1) The prefab is using multiple materials, and clothing prefabs can only use one material. So, some parts of the model will appear invisible. In this case, you will need to combine all the materials into one by joining the textures of the different materials.

2) Some issue with the model itself. I always make sure that I've applied all the model transforms in Blender and that its origin is snapped to the World Origin. (Ctrl+A Apply > All Transforms). I actually don't know if this serves any purpose, but for consistency alone it's a good idea.

I'm pretty much a newbie using Blender and Unity, so there might another reason..

Does it look right in the Unity Model Preview Window?

♥♥♥♥, i checked them again and both cases seems pretty clear. It's only one material and the transform is applied. Maybe it has something to do with the software version? What version of unity and blender are you using?

Hmm that's odd, the only other thing I could think of is maybe because of the bone weights ? I'm using Blender v2.78 and Unity 2021.1.22f1.

Have you tried it with another model? If the same happens with a different one then we could kind of assume that the models aren't at fault and it's something else.

引用自 SweetCaptn：

Hmm that's odd, the only other thing I could think of is maybe because of the bone weights ? I'm using Blender v2.78 and Unity 2021.1.22f1.

Have you tried it with another model? If the same happens with a different one then we could kind of assume that the models aren't at fault and it's something else.

Yeah, it also doesn't work too. I even brough the trillby model from the assetbundletest.

Hey, i think i figured it out, turns out your blender version was correct! And i found this post https://discussions.unity.com/t/can-we-control-which-version-copy-of-blender-imports-blend-files-for-unity-ideally-per-file/226102.

In case that thread gets deleted, basically Unity will use the version blender used to open the files from the "Open with..." functionality. And knowing that, i set the Open With .exe default to blender 2.78, and reimport it again. Which seems to do the trick!

Nice!!