Re: gEDA-user: Dead Copper

[joeft <joeft@xxxxxxxxxxxxx>]

Dan McMahill wrote:

> kmk wrote:
>
> > ST de Feber wrote:
> >
> >
> > > Can PCB remove dead copper ?
> >
> >
> >
> > No.
> > This is a feature still missing in pcb.
>
> If anyone wants to contribute this, I'm sure it would be welcomed.  
> I'd recommend having an option that sets some area threshold so the 
> user can specify "remove islands less than X mil^2 in area".
>
> I think the challenge is going to be that the copper fill is 
> implemented as a polygon with clearances drawn on top of it so island 
> removal will entail drawing more clears.  This is as opposed to a fill 
> which is done with lots of line segments where you simply delete those 
> which don't connect anywhere.
>
> It may be useful to look into the ability to specify that a copper 
> fill is done with lines vs a polygon, but I haven't really put much 
> thought into that.


Dan,

Please don't do it with lines!  Every implementation I've seen where the 
fill was done with lines was very error prone.  The current 
implementation is much better.

If lines are used:
The line width used for filling must be user controllable to get good 
results on complicated fill/plane boundaries.  It is hard for the user 
to specify an exact width for fill copper or cutouts.
"Healing" around a fill intrusion ("plow") can be tricky.
The ends of the lines leave a lot of "bumps".
Calculating connectivity can get very tricky.

Joe T

> -Dan