Why are two parts created when a reshape line must have only one part in it?

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07-24-2012 12:31 AM
TimLangner
Occasional Contributor III
Hi there

I do a lot of tracing and reshaping of digitised polygons in ArcMap 10.0.5. However semi-regularly I come across the following and can probably make it happen everytime if I wish. Is the following a bug or is it work as ESRI intended it to?

1. I  digitised a polygon.
2. Snapping is switched on and is on the tolerance is 4 pixels.
3. Next I choose reshape because I need to reshape a small section of it.
4. Now I add 3 points using the right angle tool.
5. Now I switch to the tracing tool
6. I click on the final point I previously added. Before doing so the point snapping box appears, to show I am close enough to the point itself for it to snap to it.
7. Now I start tracing and shortly stop.
8. Finally I finish the sketch
9. Now instead of the sketch finishing I get an error message:
"The reshape line must have only one part in it"

Why are two parts being created when all I wish to do is carry on from the existing sketch line? Of course at this point my sketch is deleted and I must start again.

Of course it always takes up to 10 seconds for a sketch to be deleted after an error, where as if you delete a sketch yourself normally, it's far far quicker. Less than a second. In fact this extended waiting also occurs when you get an error message when trying to save your edits. If they save OK it is far quicker than if they don't. It must be due to the way ArcMap handles error messages. Is this the same in 10.1?

UPDATE: I've found another quirk as follows.

1. If I select a polygon and then move the layer into a background mapping layer, it will rightly no longer be selectable.
2. Next I start a reshape session on another polygon which I have selected.
3. Now I move the first layer out of the background mapping layr
4. Now I trace a reshape
5. I finish the sketch
6. Now I get an error message saying:
"The reshape task could not be completed."

However instead of it then taking 10 seconds or so to allow me to continue, it simply goes straight back to the editing window within less than a second. The same amount of time it would take if it had finalised the sketch and reshaped the feature. Why the after effects of the other error messages can't be this quick I don't know.

Kind regards
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6 Replies
VincasDundzys
New Contributor
Hi all,

I am getting the same error message while working with 10.1 ArcMap version:
1. Snapping is on and I start digitzing a feature with selecting Reshape feature tool, called Straight segment;
2. After I finish my digitizing actions I double-click to end the line and get the Error message "Reshape: Reshape task could not completed.".
3. After I press ok, my newly added polyline dissapears.

Can someone give me a solution or a workaround for this issue?

B.R.
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VincasDundzys
New Contributor
Hi all,

I am getting the same error message while working with 10.1 ArcMap version:
1. Snapping is on and I start digitzing a feature with selecting Reshape feature tool, called Straight segment;
2. After I finish my digitizing actions I double-click to end the line and get the Error message "Reshape: Reshape task could not completed.".
3. After I press ok, my newly added polyline dissapears.

Can someone give me a solution or a workaround for this issue?

B.R.


Never mind. I've found a solution.
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TimLangner
Occasional Contributor III
What was your solution B.R.?
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JohnNiles
New Contributor III
What was the solution?!?!?
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TimLangner
Occasional Contributor III
Never did find out and the problem still occurs even with 10.1.1.

Tim
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TimLangner
Occasional Contributor III
I have no update to this in case it is of help to anyone else. It may be the solution user vdundzys had come across, I don't know.

Today I was tracing and I got the error message, a reshape line must only have one part in it. However I got it twice in succession, so I did the same tracing again and then zoomed in to see what was happening. See attached picture.

What is happening is that there are two vertices very close together but not along the same line I wish to trace. When I trace ArcMap is choosing to trace both of them. However it doesn't go from one directly to the other. As you can see in the attached image, there is a gap between the two.

It may be that the tracing line is doubling back on itself but I wouldn't have thought that would cause an error. Therefore it may simply be creating a spur line and then carrying on from the vertex the spur line came off, without actually going back to it before carrying on, if that makes sense.

Now the attachment shows I have really zoomed in to see this and you may be wondering why I have two points so close together. Well they are actually different data sets.

I am tracing off existing road data, which is a series of polygons. At the end of each road I trace, I need have it split from the road it joins. Although the roads are already split in the existing data, they do not follow the same convention I have to follow for the work I am doing, so sometimes I end up with points very close together. Hence the conditions for this error to occur then exist.

When I deleted the vertex that I did not require at the end of the spur line just now, I was able to finish the sketch without any errors.

What compounds the error badly, when it occurs, is the fact that ESRI have designed ArcMap so that after the error and any other sketch error occurs, the sketch disappears making it very heard to locate the cause of the error and it also makes one have to do the work again, which is most annoying. It may not seem like much but when your doing large amounts of digitising, the last thing you want is to have to repeat your steps because of such things. It's not as if the software is cheap.

Anyway I'm not sure what I would gain by taking this up with ESRI technical support but at least it is here in case it is of help to someone else.
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