Re: gEDA-user: a different approach to 3D modeling
Hi Kai-Martin, > -Original Message- > From: geda-user-boun...@moria.seul.org > [mailto:geda-user-boun...@moria.seul.org] On Behalf Of > kai-martin knaak > Sent: Friday, November 19, 2010 4:01 AM > To: geda-u...@seul.org > Subject: gEDA-user: a different approach to 3D modeling > > > Looks like there is no open 3D exchange format that fits the > need of pcb: > > a) render a beautiful image of a populated board > > b) integrate pcb in a 3D work-flow to fit the board into some > tight space. > > The existing formats are either limited to surfaces rather > than objects (STL, VRML). This prevents efficient processing > of the 3D geometry. > Or they lack attributes for eye candy (IGES). Or they are > overly complex and geared to completely different use cases (STEP) > > It might be easier to do 3D in a different way: > Teach the 3D CAD application how to read pcb files. Then, let > the CAD app retrieve 3D models that correspond to the > footprints mentioned in the layout. Use the 3D engine to > render images, or do mechanical engineering. Also teach the > CAD app to export pcb layout data from 2D shapes. > > The pcb file format contains all information needed to > reproduce the geometry of the board in a concise form. Given > the ability of general python scripting within the 3D CAD, it > shouldn't be that hard to write a *.pcb parser. Once the > geometry is known to the CAD app, it can export it to > whatever format its engine supports. > If the CAD app can be driven completely by scripting, the > conversion could be triggered from within a pcb menu. > > Benefits: > > * no need to write import/export functions for general 3D > data exchange formats. > > * only deal with well known file formats (*.pcb) > > * efficient file transfer to a 3D CAD which keeps names > objects rather anonymous shapes > > > Drawbacks: > > * no fancy 3D images in a stand-alone binary of pcb > > * beautiful images might need blender as a third major component. > > * ties to a specific 3D CAD app, which may not be everybodies > favorite choice > > Just an idea from my way home... > > ---<)kaimartin(>--- > -- > Kai-Martin Knaak > Öffentlicher PGP-Schlüssel: > http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x6C0B9F53 > > Have a look at: http://openscad.org/ And the beginning of an OpenSCAD exporter for pcb, on top of a recent (current) clone of the pcb git repository: https://github.com/bert/pcb-openscad Please give me your thoughts and opinions on both. Kind regards, Bert Timmerman ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: a different approach to 3D modeling
Looks like there is no open 3D exchange format that fits the need of pcb: a) render a beautiful image of a populated board b) integrate pcb in a 3D work-flow to fit the board into some tight space. The existing formats are either limited to surfaces rather than objects (STL, VRML). This prevents efficient processing of the 3D geometry. Or they lack attributes for eye candy (IGES). Or they are overly complex and geared to completely different use cases (STEP) It might be easier to do 3D in a different way: Teach the 3D CAD application how to read pcb files. Then, let the CAD app retrieve 3D models that correspond to the footprints mentioned in the layout. Use the 3D engine to render images, or do mechanical engineering. Also teach the CAD app to export pcb layout data from 2D shapes. The pcb file format contains all information needed to reproduce the geometry of the board in a concise form. Given the ability of general python scripting within the 3D CAD, it shouldn't be that hard to write a *.pcb parser. Once the geometry is known to the CAD app, it can export it to whatever format its engine supports. If the CAD app can be driven completely by scripting, the conversion could be triggered from within a pcb menu. Benefits: * no need to write import/export functions for general 3D data exchange formats. * only deal with well known file formats (*.pcb) * efficient file transfer to a 3D CAD which keeps names objects rather anonymous shapes Drawbacks: * no fancy 3D images in a stand-alone binary of pcb * beautiful images might need blender as a third major component. * ties to a specific 3D CAD app, which may not be everybodies favorite choice Just an idea from my way home... ---<)kaimartin(>--- -- Kai-Martin Knaak Öffentlicher PGP-Schlüssel: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x6C0B9F53 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: PCB+GL+3D Packages??
John Griessen wrote: > Here's an example of a python script that can be launched from > a python interpreter window of HeeksCAD. FreeCAD is using python for user scripting, too: http://sourceforge.net/apps/mediawiki/free-cad/index.php?title=Topological_data_scripting Note, that boolean operations are included. The application can be driven completely GUI-less. http://sourceforge.net/apps/mediawiki/free-cad/index.php?title=Scripted_objects In addition, there is a python API to the whole application. (I'd love to see this kind of scripting in pcb and/or gschem) > I don't see exactly how it would benefit the pcb project, but the > code is BSD licensed and in C++ The core of the geometry engine is Open Cascade, which is licensed in a "LGPL-like" way. http://www.opencascade.org/getocc/license/ The BSD licensed part of HeeksCAD won't get you very far. > Freecad is going to be great, but last I tried doing booleans it slowed > to a crawl and was unusable. If I cut a torus from a filleted cube, I still get three digit FPS. You may have been missing the COIN library. In this case, FreeCAD falls back to the slower Open Cascade routines. ---<)kaimartin(>--- -- Kai-Martin Knaak Öffentlicher PGP-Schlüssel: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x6C0B9F53 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: STEP Format? [WAS: Re: PCB+GL+3D Packages??]
Peter Clifton wrote: > stl (very nice) IMHO, stl is a mesh only format. That is, everything is made of triangles -- no squares, no circles, no real curvatures. There are no macros, no loops, or repetitions. A decent pcb would make for a pretty large stl file if all the vias and pin holes were to be modeled realistically. Named objects are unknown to stl. This renders stl a one way format for most construction purposes. Vital information like the diameter of holes or boolean operations of solids cannot be included. In original stl there is no way to give color or texture information. There are color extensions, though. Their color depth is confined to 15 bit. So shades tend to look like a zebra. Most of the above is true for vrml, too. Due to its ability to associate textures with surfaces, it may be the format of choice for good looking pictures. For construction purpose, it is a dead, though. > iges (simple format, but I have no clue what the syntax is ;)) syntax description is supposed to be available here: http://www.uspro.org/documents/IGES5-3_forDownload.pdf/view My browser is unable to connect, though. This format is more CAD friendly in that it allows for cylindrical, spherical and even spline defined surfaces. In addition, it knows about objects. Because of this, iges can capture the exact dimensions of engineered parts. For most CAD applications there is still loss of information on export. Surfaces are contained as is, not as rendered by construction points. Color is added by object. There is no way to attach textures to surfaces. So unfortunately, iges does not lend itself to efficient production of eye candy > STEP (_utterly_ evil format). This standard is supposed to cover every aspect in production of every industrial product, dismantling and recycling included. Even with thousands of pages, it can only scratch on the breadth of this goal. Most CAD vendors seem to have gravitated to the automotive subsection. In addition, step exports seem to limit itself to about the rage of features that iges can provide. That is, a geometrical description of the surface. The specification of the format is kept almost as a secret. I wasn't able to get a glimpse on it for free. For 3D features in pcb, all of the above suffer from some kind of deficiency. ---<)kaimartin(>--- -- Kai-Martin Knaak Öffentlicher PGP-Schlüssel: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x6C0B9F53 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: [PATCH] Fix so symbol directories cannot be loaded twice
(Apologies for top-posting, but I'm doing this from my phone) Does adding something like the following to your $HOME/.gEDA/gschemrc work? (define %component-library component-library) (define %reset-component-library reset-component-library) (define loaded-dir-libs '()) (define (component-library dir . rst) (if (member loaded-dir-libs dir) #f (begin (apply %component-library dir rst) (set! loaded-dir-libs (cons dir loaded-dir-libs) (define (reset-component-library) (set! loaded-dir-libs' ()) (%reset-component-library)) I haven't actually run it, but it might solve your problem. ;-) Peter -- Peter Brett Remote Sensing Research Group Surrey Space Centre - Original message - > Dear Peter, > > Commands of the form "(component-library )" I had placed in a gafrc > were getting called multiple times, so a lot of copies of the same > directories started appearing in my symbols dialogue box. > > The attached patch fixes that bug by preventing the same symbol > directory to be loaded twice. > > ~Matt check.patch ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: solderpaste on pads for BGAs
On Thu, 2010-11-18 at 18:40 +0100, Stefan Salewski wrote: > whenever I need to do soldering BGA myself I will do > some more research.) Maybe I will read this paper: http://www.lrr.in.tum.de/~acher/bga/motorola_bga.pdf ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: solderpaste on pads for BGAs
On Thu, 2010-11-18 at 09:17 -0500, Rick Collins wrote: > Specifically, the solder balls on the part are to provide some space > between the part and the board. The solder paste is as large as the > pad and makes sure the full pad is wet with solder and completes the > connection. > > Rick > > > At 04:23 AM 11/18/2010, you wrote: > >Hi all, > > > > > >I'd like to ask if solder-paste is necessary for BGAs. The BGA already has > >some tin, so the solder-paste on the pad wold be a bad idea. > > > >Do I miss something? > > I have never soldered BGA myself, but I have read that for new BGA parts and PCB boards made by professionals (gold or tin plated pads, solder mask) only flux is used, no paste containing tin. The tin on the BGA balls should be sufficient. For repairing/rework or home made boards solder paste may be necessary. (That may be wrong, whenever I need to do soldering BGA myself I will do some more research.) I think, if the BGA device is only available green/ROHS/leadfree then paste with lead may be helpful indeed? ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: STEP Format? [WAS: Re: PCB+GL+3D Packages??]
On 11/17/2010 09:41 PM, Peter Clifton wrote: I'm not sure there is any colour information in any of the files, I don't think STL export preserves color, and maybe not IGES either. The Heekscad original had two colors JG ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: solderpaste on pads for BGAs
Specifically, the solder balls on the part are to provide some space between the part and the board. The solder paste is as large as the pad and makes sure the full pad is wet with solder and completes the connection. Rick At 04:23 AM 11/18/2010, you wrote: Hi all, I'd like to ask if solder-paste is necessary for BGAs. The BGA already has some tin, so the solder-paste on the pad wold be a bad idea. Do I miss something? Thanks, Levente -- Kovacs Levente Voice: +36705071002 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: solderpaste on pads for BGAs
Hi Levente, Yes, solder paste is needed. Plus, it helps to fix the component so it doesn't move before the reflow process. Best regards, Carlos 2010/11/18 Kovacs Levente <[1]leventel...@gmail.com> Hi all, I'd like to ask if solder-paste is necessary for BGAs. The BGA already has some tin, so the solder-paste on the pad wold be a bad idea. Do I miss something? Thanks, Levente -- Kovacs Levente <[2]leventel...@gmail.com> Voice: +36705071002 ___ geda-user mailing list [3]geda-u...@moria.seul.org [4]http://www.seul.org/cgi-bin/mailman/listinfo/geda-user References 1. mailto:leventel...@gmail.com 2. mailto:leventel...@gmail.com 3. mailto:geda-user@moria.seul.org 4. http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: solderpaste on pads for BGAs
Hi all, I'd like to ask if solder-paste is necessary for BGAs. The BGA already has some tin, so the solder-paste on the pad wold be a bad idea. Do I miss something? Thanks, Levente -- Kovacs Levente Voice: +36705071002 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
