How do I fix this weird lighting (normals?) problem?

So I made this fork.

The middle two spikes have a sudden difference in lighting normals it would appear at their base (top of pictures). There was a large quad making up the area underneath the four vertices (seen in the top right image), so I thought maybe breaking that face into multiple would help. Instead I get these weird lighting triangles (bottom left picture).

This problem seems to persist in same way regardless of how I breakup the face.

To make it weirder I am positive that the 8 vertices at the base of the fork spikes have the same x & z coordinates, they only differ in the y axis.

What is causing this problem and how can I fix it?

If anyhow relevant, the left images are taken in Unity game engine.

• Does the weird shading also appear in Blender 3D view? I can't see it clearly in your images – Carlo Jun 11 '17 at 8:55
• it's likely because vertices composing those tris on the last screenshot aren't on the same imaginary plane while that wasn't quad on the first image, it was a big nice Ngon, likely non-planar. If really using lazy solution try selecting all tris composing base of the spikes and scaling them down by normal axis. As it might be not enough the best would be to remake that part. Related tutorial wiki.blender.org/index.php/Doc:2.6/Tutorials/Modifiers/Lattice/… – Mr Zak Jun 11 '17 at 9:34
• Carlo - yes it does, but it's very light. – danglingPointer Jun 23 '17 at 17:39

2 Answers

As others have mentioned, Unity is probably getting confused about what direction the normals should be in. You need to change the topology of the large area that causes trouble. I think this would be the most logical choice:

Have you tried this combination?
To get to it, simply delete all the "wrong" faces, insert a face (F) in their place, and cut it up using the knife tool (K).

If this doesn't work, or if you're too lazy :), try adding a Bevel modifier with a small Width.

you need to add edged from where the tines split up through the handle of the fork. The renderer is just making it's best guess at shading them without sufficient vertex data.

• I'm pretty sure I know where you are talking about and those edges are already marked sharp. Granted it's really hard to see in the image. You mean in the three spaces between tines, that little edge? Also, the top of the skinny triangles second most from the sides of the fork in the bottom right image? Yes, those edges were already marked sharp. – danglingPointer Jun 23 '17 at 17:30
• I do not mean marking anything sharp, I mean adding actual edges between each 'finger' running up to the handle.. – JustinBarrett Jun 24 '17 at 22:12
• @danglingPointer: What the image show can only be caused by tiny duplicate edges(aka, bad topology). On the second image, you have already solved your problem on the outer 2 forks. Why not adding the same support loop for the middle 2? And, plus, if you want absolutely perfect shading/blending from the forks to the palm, you'll have to not only add the support edge, but also make sure the face normal of the support loops are the exactly the same as the palm. – TeaCrab Jul 23 '17 at 1:57