All UV border edges = split vertex tangents along the border. Not vertex normals. They are different things. However since a vertex can only have one set of information, it must split the vertex, even if the normals for both vertices are identical - if the tangent is different, you need a new vertex.
Right, I was able to test this in xnormal and was able to see the tangents. So when you split your UV border edges you get two new verts but still retain a single vertex normal that is shared between those two verts? Or do you get two verts and two vertex normals, and the vertex normals just happen to have the exact same…
The tangents are derived from a mathematical calculation which takes inputs from the vertex normal and the connected UVs from that vertex. Therefore, when you split the UVs, even though the normal remains the same, the UVs have changed so the tangent basis must also change. And yes, you will then have two vertices with two…
Posting a lot of normal map questions today. I'm doing some documentation and need to figure some of this stuff out. This was taken from this site: http://ddnetworkofartists.net/index.php?itemid=34&catid=7 I'm really confused by what they mean when they say "the software breaks the tangency between one side of the vertex…
Exactly Eric, if you had a hard edge with non-averaged vertex normals then this would make perfect sense, but the fact that that doesn't appear to be the case is what's confusing me so much.
@Blenderhead: If you want your "smoothing groups" aka vertex normals to export from 3dsmax to Maya you shouldn't have a problem if you use a file format that supports it. Most do, in fact i'm not aware of one off the top of my head that doesn't. Just use OBJ or FBX and be mindfull of any options in the export/import…
Not necessarily. :shifty: When switching a UV border to a different mesh edge, even if the vertex normals are exactly the same, like in the middle of a planar surface, the tangents could still be very different. Two of the tangent axes are derived directly from the U and V axes, not from the vertex normal (which creates…
Thanks so much for taking the time to explain that Mop. That's one of the clearer explanations I have come across. I think this makes sense now. Normally changing the UVs and thus changing the tangents isn't an issue because the baker takes this change into account and changes the baked data in the normal map to…
Right, sorry, that was a poor explanation. So, at this point im back to not understanding this. Moveing that border edge could result in tangents that are still different. It seams like the article is suggesting that a break in the tangents will reult in the z axis (up axis) of the tangents pointing in a different…
Okay, I took some more time to think about this and I have attempted to formulate what I'm not understanding: I understand that anytime you break your UVs your doubling the vertices along the resulting UV border edge so you can hold the two UV coordinates. I also understand that the tangents are derived, in part, from the…