gcode generation randomized?

[siva]

I was trying to compare the changes to gcode with different settings and noticed a lot of changes. Then I saved the file twice for the same settings and was expecting only the timestamp line to change. However, I noticed a lot of changes. So, is the gcode generation slightly randomized?

[dsegel]

Yes, it's non-deterministic for some reason. I asked about this before (http://forum.simplify3d.com/viewtopic.php?f=9&t=1530) but never got a good answer. The changes seem to be in both the positioning in the X-Y coordinate and the extrusion amount, and are fairly small, e.g.:

< G1 X90.376 Y86.411 E0.0167 F1350
< G1 X91.287 Y87.383 E0.0579
< G1 X91.995 Y88.226 E0.0919
< G1 X92.533 Y88.945 E0.1197
< G1 X92.884 Y89.473 E0.1393
---
> G1 X90.376 Y86.41 E0.0167 F1350
> G1 X91.298 Y87.396 E0.0584
> G1 X92.003 Y88.237 E0.0923
> G1 X92.539 Y88.954 E0.12
> G1 X92.884 Y89.474 E0.1393

It probably has no effect on the print, but it's annoying nonetheless because it makes it very difficult to see exactly what small settings changes are doing.

[JoeJ]

Yes, it will be different if you have things turned on that randomize positioning - like random infill placement, random start points, etc.

[dsegel]

I don't have any of those turned on, but still get different gcode every time. Very slightly different, but different nonetheless. Look at the code snippet I posted. The differences are in the thousandths.

[siva]

Same for me. No random settings and still get slight changes. This makes it hard to do any kind of analysis on what's going wrong with my tweaks to the settings.