Materials don't appear the same way in different faces

Hi,

I’m still learning - currently my topic is Vertex Groups and material assignment. I got this model in DAE format:


Loaded it in MeshLab and exported it as PLY. Then imported in Blender. I started creating vertex groups and assigning materials. So far so good. But in rendered view, the separate face appear differently although they have the same material. I was thinking, maybe it’s the normals but as far as I can tell, they look OK. If I recalculate normals for a set of faces, it looks even worse… Any hints on what I should look at?




Check the correct material is applied to the correct faces.
I see no link to your blend file
The bottom image indicates that you have inverted face normals.
You should also be applying the object scale to prevent any further issues

@Richard:
Thanks for your reply! I intentionally didn’t include any blend file because the current file is pretty huge and I wanted to avoid people being too nice and fixing the file for me :). I was just after some hints where to go further. I learn best by figuring stuff out myself - just need a hint to the right direction every once in a while.
In the meanwhile I was working on making the lightbar transparent and noticed that it had 2 outer walls. After removing the inner one and splitting it into a separate object, the lightbar, which had the same problem as the chassis, looks good. So I suppose, the chassis also has 2 walls whose normals might have gone haywire. Will continue working and report back :).

  1. Did you UV unwrap the doors?
  2. Did you UV unwrap the doors?

Now, I know that’s the same question, but it’s so important, I felt I should ask it twice. :slight_smile:

One other thing…

Working with a triangulated mesh may be tricky. (I’ve never done it, so I can’t even begin to guess at the problems you may face.) I’m mentioning it because this could be part of the problem.

But with all that said…

I think the problem is that the doors are not the same size, so once you’ve UV unwrapped them, you’ll have to play around with the UV maps to get that image to show up as being the same size on both.

@rontarrant:
Thanks! Actually, I’m not using textures. I’m creating vertex groups and assigning Cycles materials to the groups. That’s the main learning point for me in this project - get experience and practice with vertex groups and materials :).

Can’t help you there. Good luck. :slight_smile:

Indeed the model seems to have every face double and the normals point inside… I’m in the process of removing all redundant faces and it starts looking good.

Yes, sounds like a side-effect of the model having been built with software other than Blender.

If you’d rather play around with a native Blender model, you could check out the list of car models on BlendSwap.com (free). If you aren’t registered, you’ll have to do so before you can download, but that’s free, too. The only Volvo I saw was the P1800, but there are plenty of late-model touring cars (or station wagons or estate wagons depending on which part of the world you in).