[GRASS-dev] TIN with desired structure?

[Markus Neteler]

How to make a defined TIN which looks like

*-----*------*
|    /   |   \     |
| /      |      \  |
*-----*------*
| \      |      /  |
|     \  |   /     |
*-----*------*

out of the following point set?

cat tin.asc
x,y,z
0,0,0
0,10,1
0,20,2
10,0,1
10,10,3
10,20,4
20,0,1
20,10,4
20,20,5

v.in.ascii -z tin.asc out=tinpoints z=3 fs=',' skip=1

The output from
  v.delaunay tinpoints out=tin
  g.region vect=tinpoints
  d.mon x0
  d.vect tin

looks quite different... I wonder if there is a trick using
centroids or just fixing the order (left hand rules?).

Markus