At 10:13 AM 1/19/2002 -0800, Brian Sherer wrote: >It seems that Polygons are handled as a multiplicity of primitives, while >Split Planes are handled as >single entities. Database size seems to grow exponentially if Polygon >Pours are used.
This is not just an appearance? Pours, by definition, consist of a pile of tracks and arcs filling an area. The size of the pour depends on the pour parameters, but, inherently, a pour involves many more primitives than a negative plane. This is the reason I have recommended so many times that Protel move away from pours and toward positive/negative merges for filling areas. The only reason for using pours is that the copper is explicit, making checking possible without any additional special programming. But this leaves negative planes without explicit checking, which is an undesireable situation by itself. In other words, the negative plane checking problem should be solved, and if it is solved, it then becomes practical to use negative merges to accomplish what pours now accomplish, with the benefits of reduction of database size, elimination of pour anomalies -- which can be quite a nuisance --, and, to boot, substantial reduction of plot sizes. But I want to emphasize that this problem is not a special Protel problem. Most CAD systems don't check negative planes, it is not a trivial problem. But it is soluble, and I presume that Protel's programmers know how to solve it, since they haven't asked me! :-) >2) For a design that has been heavily edited, there may be Polygons or Split >Planes that exist in the database but are not displayed, or that duplicate >existing objects. Some methods were given for locating and eliminating such objects. A generic technique for dealing with suspected persistent database corruption is to chop the file into pieces and find out if the problem exists in all the pieces. The spreadsheet might be useful for keeping pieces distinct.... This technique can be useful when all else fails.... The current Protel router, while quite serviceable for many applications, is not considered state-of-the-art. It will be *very* interesting to see what we get in the next few months! [EMAIL PROTECTED] Abdulrahman Lomax Easthampton, Massachusetts USA * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
