Re: importing GDSII files ?

[Kevin Thomas <kjt@sgi.com>]

A few notes on the GDS-II translator:

1. It's the newest translator, so it isn't highly refined or tested.

2. There is a very crude mapping from GDS-II 2-D outlines into LC 3-D
primatives (cube or cylinder).  The rules are based on the number of
points in the outline:
  1 point maps to a infinitesmally small cube
  2 points map to a thin wire
  3 or 4 points are an error flagged as a red bounding box
  5 points map to a regular cube (most outlines have 5 points)
  more than 5 points are mapped into a cylinder if the bounding box
    is square (i.e., the cylinder must be round).
  if none of these apply, the geometry is flagged as a red bounding box
  (more rules could be added, if you tell me a good heuristic)

3. Rotation and scaling (which are allowed in GDS) are not supported
(these could be added pretty easily, but I didn't bother in the
initial translator because I didn't find any files using these
features).

4. If you build up several layers by reading several GDS-II files,
you'll
probably need a drill file to connect them all together.

After importing a GDS-II file, you might want to try selecting all red
blocks, to see if there were any translation errors.  You might be able
to manually repair these blocks, or you might just delete them.  Often
these might be extraneous items like annotations.

-- 
Kevin Thomas    kjt@sgi.com    tel 1-651-683-3624
http://reality.sgi.com/kjt/     or 1-800-284-2729 x33624