kicad-developers team mailing list archive

[Cirilo Bernardo <cirilo_bernardo@xxxxxxxxx>]

----- Original Message -----

> From: Lorenzo Marcantonio <l.marcantonio@xxxxxxxxxxxx>
> To: Kicad Developers <kicad-developers@xxxxxxxxxxxxxxxxxxx>
> Cc: 
> Sent: Thursday, December 5, 2013 2:23 AM
> Subject: Re: [Kicad-developers] Development of IDFv3 export
> 
> On Wed, Dec 04, 2013 at 09:24:15AM -0500, Wayne Stambaugh wrote:
>>  What is missing from the board file format that is required to export to
>>  IDFv3?  None the the other exporters required any changes to the board
>>  file format.  I'm not thrilled about the idea of changing the board 
> file
>>  format just to satisfy exporting to another file format.
> 
> I already did some feasibility study a while ago, nothing is needed
> (except some way to convey height information for the modules, if
> wanted). Also if he picks the segment in the board instead of taking the
> bounding box he will a) handle the more-common-than-you-think case of
> nonrectangular boards and b) not need the 0.1mm reduction hack.
> 


That's a good idea. If we could extrude a courtyard rather than the silkscreen outline then we would meet all the functional mechanical requirements of IDF3 by simply adding a height to each component. Extruding an outline of the silkscreen won't quite work though since in many cases it won't serve the purpose of the mechanical fit check. On the other hand, maintaining component outline files in the manner that we maintain VRML files would be a royal pain in the ass - so much so that, in the absence of courtyard outlines, I am tempted to simply extrude the silkscreen outlines simply to provide some sort of markers and give the users a general idea of the component locations. I see the IDF exchange with MCAD as good enough for many purposes, but things will be much better when/if I get around to doing proper 3D modeling.

> Every structure in the IDF3 is defined by wound polylines (board
> counterclockwise, cutouts clockwise), each segment can be a line or
> a circular arc segment. So nothing in pcbnew can't be represented in
> IDF3 (some math required:D)
> 
> A better work could be done for holes, since IDF distinguish between
> mechanical, tooling, via and pins... since an NPTH hole is definitely
> a mounting hole, the only doubt is the plated hole (can be a pin or
> a 'grounded' mounted). Heuristics could help, maybe. Or maybe simply
> nobody cares about the difference (like for some things in gencad).
> 
> 


Ultimately the MCAD doesn't care about the holes; with SolidWorks I simply have a cut outline named "PTH" which contains the location and size of all PTH and the same goes for NPTH. Even the mounting holes which happen to be plated go into PTH, so I can't even distinguish mounting holes from others based on the name or grouping within SolidWorks.

- Cirilo