Examples: connect 2D
The objective is to connect a set of random points into a triangle mesh.
| Input Random Points | Output Triangle Mesh (boundary nodes red) |
|---|---|
 |
 |
- Create a mesh object named mo_tri and create a set of random points within a box.
- Connect and Set node itp to mark boundary nodes.
- Check mesh quality and write mesh file.
Input Commands
# create a 2D mesh object
# triplane has ndimensions_topo=2 and ndimensions_geom=2
cmo / create / mo_tri / / / triplane
# Make some points at the four corners
createpts / xyz / 5 5 1 / 0. 0. 0. / 1. 1. 0. / 1 1 1
# Add some random points and delete duplicate points
createpts / random / xyz / 0.4 / 0.1 0.1 0. / 0.9 0.9 0.
filter / 1 0 0
rmpoint / compress
# set some defaults for the connect routine
# imt material set to 1 and itp boundaries set to 0
cmo / setatt / mo_tri / imt / 1 0 0 / 1
cmo / setatt / mo_tri / itp / 1 0 0 / 0
connect
# set default materials and boundary tags
cmo / setatt / mo_tri / itetclr / 1 0 0 / 1
resetpts / itp
# check areas and write an AVS format file of the mesh
quality
dump / avs / tri.inp / mo_tri
Output from quality command
This quality report confirms all areas are positive and the triangles do not have small aspect ratios.
epsilonl, epsilonaspect: 3.1401849E-13 3.0964614E-38
--------------------------------------------
elements with aspect ratio < .01: 0
elements with aspect ratio b/w .01 and .02: 0
elements with aspect ratio b/w .02 and .05: 0
elements with aspect ratio b/w .05 and .1 : 0
elements with aspect ratio b/w .1 and .2 : 0
elements with aspect ratio b/w .2 and .5 : 1
elements with aspect ratio b/w .5 and 1. : 51
min aspect ratio = 0.4160E+00 max aspect ratio = 0.9885E+00
epsilonvol: 4.4408921E-13
---------------------------------------
element volumes b/w 0.6647E-02 and 0.9188E-02: 2
element volumes b/w 0.9188E-02 and 0.1270E-01: 18
element volumes b/w 0.1270E-01 and 0.1756E-01: 3
element volumes b/w 0.1756E-01 and 0.2427E-01: 16
element volumes b/w 0.2427E-01 and 0.3354E-01: 13
min volume = 6.6465893E-03 max volume = 3.3543824E-02
-----------------------------------------------------------
52 total elements evaluated.
Old Example Antler Ridge
Note this old example is non-convex and has long tets outside the boundary that need to be removed.