[[ FEMESH.TXT : 2891 in FEMESH.TXT ]]
The attached ASCII text file has been cut as single block of text and not
edited in any way and taken from a shell mesh .UNV file output, SDRC Ideas
version 2.1 CAD object.
The object for simplicity and small file size was a single rectangular
planar surface. The surface meshed with 18 triangular elements this gives 16
nodes.
This can be seen in the file FEMESH.TXT as the first word of the 1st, 3rd,
and 5th lines are 1, 2, and 3.
The 1st, 2nd and 3rd words of the 2nd, 4th and 6th lines are the values of
X Y and Z.
This repeats for all 16 nodes. ( therefore a program would need to store 16
variables )
The next range of numerics
1 91 1 1 7 3 *
1 2 5
2 91 1 1 7 3 *
2 6 5
3 91 1 1 7 *
2 3 6
The 1st word of each odd line ( Highlighted with * ) denotes the element (
Facet ) and
the 1st, 2nd and 3rd word of each even line denotes the node values that
belong to that facet.
eg
element 1
node 1
node 2
node 5
element 2
node 2
node 6
node 5
element 3
node 2
node 3
node 6
or in co ordinate terms
element 1
node 3.7567994054971329D+01 -2.9616542319360086D+01 0.0
node 3.7567994054971329D+01 -8.8576936497491090D+00 0.0
node 1.6160060049852451D+01 -2.9616542319360089D+01 0.0
element 2
node 3.7567994054971329D+01 -8.8576936497491090D+00 0.0
node 1.6160060049852451D+01 -8.8576936497491090D+00 0.0
node 1.6160060049852451D+01 -2.9616542319360089D+01 0.0
element 3
node 3.7567994054971329D+01 -8.8576936497491090D+00 0.0
node 3.7567994054971329D+01 1.1901155019861873D+01 0.0
node 1.6160060049852451D+01 -8.8576936497491090D+00 0.0
this in STL terms will be
solid
facet normal 0 0 -1
outer loop
vertex 3.7567994054971329D+01 -2.9616542319360086D+01 0.0
vertex 3.7567994054971329D+01 -8.8576936497491090D+00 0.0
vertex 1.6160060049852451D+01 -2.9616542319360089D+01 0.0
endloop
endfacet
facet normal 0 0 -1
outer loop
vertex 3.7567994054971329D+01 -8.8576936497491090D+00 0.0
vertex 1.6160060049852451D+01 -8.8576936497491090D+00 0.0
vertex 1.6160060049852451D+01 -2.9616542319360089D+01 0.0
endloop
endfacet
facet normal 0 0 -1
outer loop
vertex 3.7567994054971329D+01 -8.8576936497491090D+00 0.0
vertex 3.7567994054971329D+01 1.1901155019861873D+01 0.0
vertex 1.6160060049852451D+01 -8.8576936497491090D+00 0.0
endloop
endfacet
That seems to be the way the .UNV may be converted to STL if there is a
IDEAS expert that can describe the reasoning of the .UNV shell mesh format I
would like to find out more.
I hope that Greg Morwood finds this assumption of some use.
Jan Andrzejewski
Pera
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
This archive was generated by hypermail 2.1.2 : Tue Jun 05 2001 - 22:45:57 EEST