Materials with normal map look strange

[pschuster]

I have tried for hours but I don’t get it to work. I try to replicate a metallic surface for a watch body. It’s brushed Aluminum. It has a metallic and a roughness map (combined into one map). The model is loaded using the ObjectLoader and the LegacyJSONLoader for loading the geometry from JSON.

The material also has a normal map, which currently is just plain (128,128,255) for testing purposes. It has that standard blueish/purple tone to it. From my understanding, this normal map should do nothing, as all normals are poiting up. I did not change the normal type (so its Tangent space).

However, if I set the normal map, it does look really strange. The object does not have any depth or form, it looks like the object cuts out the environment, like a refraction map. But the environment is reflection type.

If I remove the normal map via the Browser console (Chrome) it looks immediately good. So there is something fishy about the normal map or the way I use it, but I cannot figure it out.

I have attached a view screenshots so you can see what I mean.

[EliasHasle]

This may be a stupid question, but are you 100% sure that you have applied the normal map that you are describing? The file name says “BumpMap”. Applying a bump map as a normal map would be expected to produce strange results.

If yes, is there a chance that the texture format specifier does not match the format of the texture? E.g. interpreting BGR as RGB.

[pschuster]

Thanks so much for thinking about that. Actually, just after you responded it suddenly worked. First, I think I had the normal map flipped (it’s been green, that is b has been 0 instead of 1). Then, to fix the issue, I changed the materials to use ObjectSpaceNormalMaps. Then, I noticed my normal map is not correct and flipped it, but I forgot to remove this setting:

materialInstance.normalMapType = THREE.ObjectSpaceNormalMap;

Once I removed that setting again, it looked good.

So, everyone having strange issues with Normal Maps, have a look at the normalMapType.

Thanks so much for looking into that.

Now, this looks better :-).