In the process of playing with this idea;
http://www.cambam.co.uk/forum/index.php?topic=7047.msg57413#msg57413I found or rediscovered that issues exist when using Edit->Offset on an entity that is not at Z=zero.
What happens is, the created offset entity always sits at zero on the Z plane regardless of where the original entity was placed.
This plugin, offset2.dll
1. is found at menu position, Edit->Offset+Z
2. e.g. if a circle is at Z = -10 then the created offset polyline will also be at Z = -10
3. entites must be flat in the Z plane, i.e. all their points must have the same Z value.
4. works with CamBam 0.9.8 and 1.0
5. works with , polyline, polyrectangle, line, arc, spline, circle
The image shows an example where the Red lines were offset by 1/4" resulting in the Cyan lines.
This is handly when using slices in the Z plane and offsets are required.