Unnecessary Concern of the Day: Snapping Beyond a 1:1 Scale

An ongoing head-scratcher for me has been why my points/lines/polygons look "off" in ArcMap when zoomed in beyond a 1:1 scale. Today, I found the answer to my question! A question, it turns out, that I didn't need to worry about in the first place.

The explanation I found for this issue is summed up as follows:
"Viewing linework at a viewing scale of less than 1:1 will show apparent offsets that are not real - i.e. they are not really what is going on. The polygons could be totally coincident, but below 1:1 look off. So some visually-seen disconcerting gaps/overlaps are actually not issues."

Here's ESRI Supports explanation:
"As per our phone interaction, a map scale past 1:1 is a known limitation of our software because at a scale of 1:1, the screen display is equal to the actual distance of objects on the earth's surface (i.e. an inch on your screen is equal to an inch on the ground). When you go past that scale, it may appear that features are overlapping (when in reality) what you are seeing is the actual software resolution tolerance pushed past it's maximum threshold. In essence, the entire screen is only one point (at a map scale of 1:0), which is why your work flow is producing inaccurate results."

Original Thread Here: https://community.esri.com/thread/180322

In other words, don't be fooled by the illusion beyond a 1:1 scale! Everything is Fine.....probably. Maybe set up a few topology rules to ease your worries for good?

Using ModelBuilder to Streamline Editing in ArcMap

Recently I was tasked with creating section lines (from township dimensions and attributes contained in legal descriptions) for several counties in Minnesota.

Existing data was deemed insufficient for our project's purposes, so the lines would need to be manually created, on a case by case basis, in order to accurately plot data.

Maintaining the integrity of the section line feature class was very important, and would dictate the accuracy of other steps in the process.  Thus, creating section lines that were both accurate and topologically sound became my primary concern.  Creating sections without overshoots, dangles, or extraneous points was the primary goal here, and I wanted to ensure I streamlined the process to remove human error during the editing process.  The section lines themselves didn't need to be perfect, but we needed to be consistent in our approach.

The first step in the process involved close examination of aerial imagery, and unfortunately could not be modeled.  The mapper would need to carefully draw a centerline along a road, fence, or other visible use-line in order to establish the boundary of each section.  Next, the Copy Parallel tool was utilized to offset each line by 1320 feet.  The result of this manual operation is a grid, as depicted in the image below.

Image 1 - Section lines before running custom tool

As you can see, the grid contains a number of errors including line overshoots, dangles, and extraneous vertices.

The tool below, is aimed at correcting these issues without manual edits.



Image 2 - "Finalize Section Lines" tool developed in ModelBuilder



Image 3 - "Finalize Section Lines" tool

The end result of the model, should look something like the image below.  Nice, clean lines, with 2 vertices per edge.

Image 4 - End Result