Parametric coordinates of surface are not normalized to 1 (C API)
Hi,
There seems to be a problem with the parametrization on surfaces within the C API. I am unsure whether this is also the case in the other API's. Although the function gmshModelGetParametrizationBounds states that the minimal and maximal values are 0 and 1 for both surface coordinates [u,v], the coordinates that one receives with gmshModelGetValue lie outside the surface for any u = 1 or v = 1 (for tutorial t1).
Apparently, there is no normalization between surface coordinates [u,v] and global coordinates [x,y,z]. For example, [u,v]=[1,1] yields [x,y,z] = [1,1,0] for the tutorial. Similarly, when I give the plane of tutorial t1 an incline of 0.2 (i.e. on one side of the plane z=0.2), [x,y,z] = [1,0.832,0.555] for [u,v]=[1,1]. This confirms that the surface coordinates [u,v] are not normalized, given that hypot(0.832,0.555) = 1.
I attached a modified version of tutorial t1, where this problem is demonstrated. I hope you can help out and thanks in advance!
Best regards, Ruben