Highly n00bish question

[Pilchard123]

What exactly is a convex mesh? THIS video (around 12:00) says that it involves the mesh going "inwards" - however the example that is given I find rather confusing because just a couple of vertices along the mesh...it goes inwards. Why could the part the speaker highlights not just be an extension of the curve to the lower-left? I would post over there, but they aren't too great at replying after a couple of months, and that video was posted in February.

EDIT: I know the difference between convex and concave in other contexts - lenses and stuff, but have never got the hang of it with CG.

EDIT AGAIN: After watching that part of the video again...Is the criteria (criterion?) for a mesh being convex that you can connect any vertex to any other vertex with a straight line that DOES NOT leave the "inside" of the geometry?

[Lord Crc]

After watching that part of the video again...Is the criteria (criterion?) for a mesh being convex that you can connect any vertex to any other vertex with a straight line that DOES NOT leave the "inside" of the geometry?

Pretty much yes. A convex polygon is one where you can connect any two vertices without crossing an edge. So for a mesh it means you can connect any two vertexes without crossing a face.

[jeanphi]

EDIT AGAIN: After watching that part of the video again...Is the criteria (criterion?) for a mesh being convex that you can connect any vertex to any other vertex with a straight line that DOES NOT leave the "inside" of the geometry?

Actually since the inside of a mesh sometimes doesn't exist, the definition is that you can connect any 2 points on the surface without intersecting the surface.

Jeanphi

[Pilchard123]

Okay, thanks.