I am using the Multiple Ring Buffer and noticed that my output buffers (in this case, 10 miles) are much more generalized than I would get using the regular buffer tool with defaults for the same distance. I have tried to tweak xy resolution and I cannot get a finer resolution than below (approx 3,500 feet between points).
I get the same thing with geographic coordinates and projected (us_foot) coordinates.
Is this a known issue with the Multiple Ring Buffer?
Thank you,
Randy McGregor
Solved! Go to Solution.
So I tested a few workflows that proved to be interesting.
So what I'm seeing is all the tools/workflows except the multi-ring buffer tool creates a true curve for output. Not sure why but that seems to be what's happening. Depending on how my multi-ring buffers you need to create, you might look at some other GP tools/editing to create the smoother polygons of the true curve variety. Perhaps Esri Support Services has a good answer why the multi-ring buffer tool does not create true curves?
Buffers are represented by an "ngon" ( a n-sided polygon) historically done using 36 or 72 sides representing 1 or 1/2 degree increments. You can see this if you buffer a point, then convert the buffer to points and do a quick count of the number of points along the buffer's perimeter
Thanks Dan. When I just do a straight buffer with the buffer tool at 10 miles, the output is much smoother. Is there any way to control this? xy resolution doesn't affect it (and ESRI recommends not tampering with it).
I failed to add "historically"
True curves for simple polygons in a geodatabase, but certainly not for shapefiles.
I haven't seen true curves for multiring buffers before, but I really wasn't looking. I can only surmise that an ngon would be the default.
As a test, make 2 single buffers around a point... then do an intersect/union or one of the other overlay tools and see whether true curves are maintained or ngons geometry results.
Test 2. use the append polygon tool to a buffer and append some randomly shaped polygon... is the true curve for the buffer retained? or does it get changed...
lots of questions... most won't even notice 😉
Thanks. The features will be used for spatial analysis, but yes it is very unlikely this would be noticed.
So I tested a few workflows that proved to be interesting.
So what I'm seeing is all the tools/workflows except the multi-ring buffer tool creates a true curve for output. Not sure why but that seems to be what's happening. Depending on how my multi-ring buffers you need to create, you might look at some other GP tools/editing to create the smoother polygons of the true curve variety. Perhaps Esri Support Services has a good answer why the multi-ring buffer tool does not create true curves?
Thank you! That squares with my experience and is what I suspected. I actually have a multiring buffer tool I made, but it is clunky and time consuming (buffer,update,merge,repeat...). Running 'smooth polygon' with the bezier options on the multi ring buffer output works but it's an extra step. You answered my question. It might work ok as is, but now I know what I need to do if it isn't.
Thanks!
'Difference between Multi Ring Buffer output ('Original') and after running Smooth Polygon tool with bezier option.
Another interesting feature of this tool is that if you expose the 'Distances' input as a parameter, it will NOT work in a model. I've tried several times. It fails to recognize the input. If you remove the parameter, it works.
This is a bug that is resolved in our current 2.9 daily builds, which will likely be backported to a 2.7.x and 2.8.x patch.