Hi,
On 2019-12-17 6:09 p.m., Lee Eddington wrote:
So for the first question I asked below, I was referring to your statement that "When
you cross 360 degrees, some projections have difficulty dealing with that.” My lines
don’t technically cross 360 deg, but they cross 0 deg, as the data values for the line
positions are all > -360 and < 360 deg. So they cross at 0 deg with values like
-0.345, 33.00 to 0.231, 32.94.
If line cross a 0 deg, this could be a problem for some projects. Can
you zip a project folder and send it?
I was able to save the densification layer to a file as you suggested, but when
I do that the lines in the densified file will only display when the zoom is
for the full extent of the layer like the original file. Only if the densified
lines are in a temporary scratch layer will they display at other zoom levels.
Regarding the other suggestion "It's likely a corrupt spatial index on the
file. Try removing and recreating it.”. I don’t know how to find, remove and
recreate a corrupt spatial index. Any instructions on how to do this would be
appreciated.
You can right click on the layer, select Source, Create Spatial Index.
Thanks,
Lee
On Dec 17, 2019, at 1:54 PM, Nicolas Cadieux <nicolas.cadi...@archeotec.ca>
wrote:
Hi,
Not sure for question one. Have you tried creating a spatial index as others
have suggested? When you run the densify tool, If you don't specify the name,
the output will be a temporary layer. You should be able to do a save as for
the layer. Remember to close the temporary file after exporting it or else you
will get that message.
Nicolas
On 2019-12-17 12:51 p.m., Lee Eddington wrote:
If my layer extent is > -360 and < 360 am I really crossing 360? I’m crossing
0 from negative values to positive values. Is that the same?
Also, regarding not being able to save the layer I created with densification,
when I try to close QGIS it says I have a ’scratch’ layer that will be lost,
which would be this layer created by densification. How do you save a scratch
layer?
Best,
Lee
On Dec 16, 2019, at 7:43 PM, Nicolas Cadieux <nicolas.cadi...@archeotec.ca>
wrote:
Hi,
When you cross 360 degrees, some projections have difficulty dealing with that.
Try not crossing that or try splitting the shapes that cross it.
Nicolas
Le 16 déc. 2019 à 22:32, Lee Eddington <lee.w.edding...@gmail.com> a écrit :
I’m not sure that’s the reason as I have plenty of points in my lines. Also,
I saved the densified layer to disk, but the saved layer has the same display
problem as the original layer.
Lee
On Dec 16, 2019, at 8:35 AM, Nicolas Cadieux <nicolas.cadi...@archeotec.ca>
wrote:
Hi,
If you have a very long straight line represented by only two point,
reprojection operates only on those two points (called vertices or nodes). The
lines just represent a straight connections between two point. The problem is
that the earth is round (contrary to some popular belief :) and those long
straight lines need to be bent depending on the projection being used. Since
reprojection and zooming only operates on vertices or nodes, densification adds
nodes to the line giving more points to calculate and thus, less errors.
Cheer!
Nicolas
Le 16 déc. 2019 à 10:23, Lee Eddington <lee.w.edding...@gmail.com> a écrit :
Hi Nicolas,
Vector densification worked. I went with the default 1 vertices to add and it
created a new layer that now displays at any zoom level. Can you explain why
my original layer doesn’t display?
Thanks,
Lee
On Dec 14, 2019, at 3:13 PM, Nicolas Cadieux <nicolas.cadi...@archeotec..ca>
wrote:
.
.
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