[x3d-public] Extrusions, take 3

[Alekseyev, Vsevolod (NIH/NIAID) [E]]

>> 1) When the spine goes (0,0,0)-(0,-1,0), what is the CSP?

> I'm not seeing where the specification defines the spine-aligned cross-section plane (SCP) when only 2 unique points are provided.

It does: " If the entire spine is collinear, the SCP is computed by finding the rotation of a vector along the positive Y-axis (v1) to the vector formed by the spine points (v2). The Y=0 plane is then rotated by this value." The problem is that the rotation of the +Y vector to the -Y direction is not uniquely defined.