http://en.wikipedia.org/wiki/Defect_(geometry)

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

P.s. that 1st link is mangled, sorry. Just search for "defect geometry" on Wikipedia, I guess. Basically you need to get all triangles associated with a vertex, then loop through them and add up the total angle at that vertex. If the angle is 2pi, then there is no "curvature" at that vertex (the triangles are all coplanar)... If not, then it's "curved" at that vertex. Repeat for all vertices.

### Show differencesHistory of post edits

### #5taby

Posted 05 November 2012 - 08:55 AM

http://en.wikipedia.org/wiki/Defect_(geometry)

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

P.s. that 1st link is mangled, sorry. Just search for "defect geometry" on Wikipedia, I guess. Basically you need to get all triangles associated with a vertex, then loop through them and add up the total angle at that vertex. If the angle is 2pi, then there is no curvature at that vertex (the triangles are all coplanar)... If not, then it's "curved" at that vertex. Repeat for all vertices.

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

P.s. that 1st link is mangled, sorry. Just search for "defect geometry" on Wikipedia, I guess. Basically you need to get all triangles associated with a vertex, then loop through them and add up the total angle at that vertex. If the angle is 2pi, then there is no curvature at that vertex (the triangles are all coplanar)... If not, then it's "curved" at that vertex. Repeat for all vertices.

### #4taby

Posted 05 November 2012 - 08:55 AM

http://en.wikipedia.org/wiki/Defect_(geometry)

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

P.s. that 1st link is mangled, sorry. Just search for "defect geometry" on Wikipedia, I guess. Basically you need to get all triangles associated with a vertex, then loop through them and add up the total angle. If the angle is 2pi, then there is no curvature (the triangles are all coplanar)... If not, then it's "curved" at that vertex. Repeat for all vertices.

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

P.s. that 1st link is mangled, sorry. Just search for "defect geometry" on Wikipedia, I guess. Basically you need to get all triangles associated with a vertex, then loop through them and add up the total angle. If the angle is 2pi, then there is no curvature (the triangles are all coplanar)... If not, then it's "curved" at that vertex. Repeat for all vertices.

### #3taby

Posted 05 November 2012 - 08:54 AM

http://en.wikipedia.org/wiki/Defect_(geometry)

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

P.s. that 1st link is mangled, sorry. Just search for "defect geometry" on Wikipedia, I guess. Basically you need to get all triangles associated with a vertex, then loop through them and add up the total angle. If the angle is 2pi, then there is no curvature (the triangles are all coplanar)... If not, then it's "curved".

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

P.s. that 1st link is mangled, sorry. Just search for "defect geometry" on Wikipedia, I guess. Basically you need to get all triangles associated with a vertex, then loop through them and add up the total angle. If the angle is 2pi, then there is no curvature (the triangles are all coplanar)... If not, then it's "curved".

### #2taby

Posted 04 November 2012 - 09:48 PM

http://en.wikipedia.org/wiki/Defect_(geometry)

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own. In order to figure out the curvature at a vertex you'll need to have the adjacency data for your mesh, which I'm pretty sure is not something that an OBJ file contains, so you'd have to do that yourself. Once you do that, and know how to calculate the curvature, you'll be pretty knowledgable and you'll be able to figure out all kinds of other cool things. It's tough the first time around, but there are lots of people here who can help if you get stuck.

### #1taby

Posted 04 November 2012 - 08:56 PM

http://en.wikipedia.org/wiki/Defect_(geometry)

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own.

http://en.wikipedia.org/wiki/Gauss-Bonnet_theorem

If you feel like getting to the heart of it on your own.