Polygon topology exports extra records to shape file

[jim.dahl]

I can create polygon topology of lakes with a centroid that is a unique ID and export it to a shape file. However, the shape file has extra records in it without any features. I have to just delete the extra records. Any one ever heard of this? You might need ACAD 2004 level at least for the topology export feature.

Thanks for all of your help.

Jim

[hingles]

Jim are you running a drawing cleanup on that data prior to creating the topology? If not, I would suggest this. Also, exactly what extra data records are you getting on export? They might point to a clue as to inhibit getting them.

[jim.dahl]

Yes, I have tried everything I can think of to purge this DWG of the persistent evil spirit - a ghost record. I have cleaned and Cleaned and exploded and cleaned and purged and cleaned some more. I have attached a drawing of one polygon with the topology built. When I export the topo it shows up with two records. Of course when I import back to ACAD, only one records shows in OD table. The only way to rid the ghost is to re-import, but that is my last resort. Of course I can delete the extra records in the shape file and do this every time I edit and re-create topology.

Hope this helps.

Jim

[hingles]

Jim, I will look at the attached DWG, however it could be that the extra record is in the source file, or does this data start in MAP, or is it coming from some other source, i.e., ArcMAP, ESRI theme, Tiger Line Graphis files, etc?

[MHultgren]

Jim & Hingles,
Do you think that extra data may be coming from the infamous ACADD_ZZ block? It also carries such things as the $ModelSpace and $PaperSpace block info in it. When you try to revert DWGS from later releases back, in order to get rid of the pesky Drawing Created in a Future Version and all the ARX_Error messages, I have had to erase and purge this block, then purge the $ blocks as well. Sometimes I can get them out and sometimes I cannot.

[jim.dahl]

I forgot to mention that it follows the entity, such as when I copy and paste it into a new drawing as was attached. Does the block follow the entity? I do not remember ever using blocks. This drawing originally came into being when I imported Shape file polys, and cleaned them and brought them into shape files to add more vertices and then imported back into CAD to smooth and simplify. Then they were cleaned and cleaned again.

Thanks for the suggestion. But I copied this entity into a new drawing and exploded it and re cleaned it back into one entity again. I noticed that when I bring into other GIS software as a shape file, the extra records do not appear. Could it be an ESRI thing??

Jim

[MHultgren]

Hello Jim,
The ADCADD_ZZ block is automatically generated by LDT ( and possibly ACAD itself I believe) but it sounds like ESRI may be picking it up. In your drawing that you import after cleaning, switch to PaperSpace and run Qselect and search for Blocks with the name of ADCADD_ZZ. Even if you only have a basic vport in the drawing, Qselect should show Multiple as your default selection option. You have to TELL it that you want to search for blocks in order to find it.

[jim.dahl]

I have tried the qselect and never have found anything other than LWPOLYLINE.

Attached screen shot of example. When I export poly on the right, the ghost poly on the left follows. When I export the poly on the left, only its record comes through, not the entity. When I export topology for the poly on the left, It imports to Arc View as two records; one as an entity that appears as a poly but the attributes say it is a point; and two as a blank record, but its attribute says it is a poly.

I am sure that sounds confusing.

I also tried exporting to DXF- it appears to strip the ghost, and I will have to see if this is feasible. I tried cleaning the DXF file and killed it after half an hour.

Jim

[hingles]

those extra records are coming from a temp table that is created at the same time you create your topology, experiment a little with your export options and you can exclude them from the exported shape file

[jim.dahl]

Hi and thanks for response. Just curious about this table. The problem is still there even if no topology is in the drawing. For example, if I export the line as a polygon you will not see it but the record exports, even though the poly next to it comes across as visible.

It is strange that the line shows when exporting the line as a line instead of a poly. Also if I export another line as a poly in this drawing, the problematic one still comes with with its correct area, handle centroid and everyother property.

Jim