Cannot get rid of the grid lines after splitting shapefile into grid

[Jonas]

I am trying to optimize map rendering performance by splitting a shapefile with large complex polygons into a grid.

I am using your sample implementation that I found here: http://wiki.thinkgeo.com/wiki/map_suite_services_edition_spatial_functions_samples#split_polygon_based_on_grid

After running the polygon splitter, two new shapefiles are created: AreaSplit and LineSplit. When I load the AreaSplit shapefile into the map, it works great, except that I can see all the new lines where the polygons have been split.

I want to get rid of these lines, so that the shapefile appears to the user as if it has not been split into a grid.

I follow this video guide: http://download.thinkgeo.com/Videos/Wiki/IncreasingPolygonPerformance.wmv
where I learn I can set the Outline color of the AreaStyle to transparent, and the grid lines should become invisible (05:10 into the video).

Unfortunately, this leaves a thin gap between the polygons, through which the underlying layer is visible - in effect the grid lines are still visible. This does not happen in the video.

I have tried everything I can think of to get rid of this gap:
Setting OutlinePen to null,
Setting OutlinePen.Width to 0,
etc.
Nothing seems to help.

Can you point me in the right direction?

[Ethan]

Hi Jonas,

Thanks for your detail information, I tried to reproduce that with our cntry02 shape file but it looks i failed complete that, I even cannot split the data succeed.

If possible could you please upload the modified sample with data so I can quickly reproduce it?

And do you have some special requirement for render that just like you need modify the style frequently? Because I think open tile cache can make the performance get better just like split them.

Regards,

Don

[Jonas]

I had to make a little change to the sample to make it work.

In the SplitPolygons.cs code behind, these lines causes the exception:

if (areaIntersection != null)
{
	Feature newFeature = new Feature(areaIntersection);
	newFeature.ColumnValues.Add("RECID", feature.ColumnValues["RECID"].ToString());
	targetAreaShapeFile.AddFeature(newFeature);
}
if (lineIntersection != null)
{
	Feature newFeature = new Feature(lineIntersection);
	newFeature.ColumnValues.Add("RECID", feature.ColumnValues["RECID"].ToString());
	targetLineShapeFile.AddFeature(newFeature);
}

Add a check like this:

if (areaIntersection != null)
{
	Feature newFeature = new Feature(areaIntersection);
	if (feature.ColumnValues.Count > 0)
	{
		newFeature.ColumnValues.Add("RECID", feature.ColumnValues["RECID"].ToString());
	}
	targetAreaShapeFile.AddFeature(newFeature);
}
if (lineIntersection != null)
{
	Feature newFeature = new Feature(lineIntersection);
	if (feature.ColumnValues.Count > 0)
	{
		newFeature.ColumnValues.Add("RECID", feature.ColumnValues["RECID"].ToString());
	}
	targetLineShapeFile.AddFeature(newFeature);
}

Then it should run fine.

I have tried with the countries02.shp from the SampleData folder and it seems ok.

Jonas

[Ethan]

Hi Jonas,

Thanks for your share!

That’s helpful to me and I think it also will be helpful if someone else met the same issue.

Regards,

Don

[Jonas]

So… back to my original question, how do I get rid of those gaps?

[Ethan]

Hi Jonas,

Please just set the style of Outline Color equal to the style of fill color, which will works just like my screen capture as below:

Regards,

Don