Scale conformity between FT3 and CC3+?
kmunoz
Newcomer
I use FT3 to create world maps and export chunks of them into CC3+. I'm noticing that the correct scale doesn't seem to be retained, so that all the distances are wildly off. Is this just a function of the way the exporter works (i.e., it doesn't worry about scale) or is there something I can do in a setting to fix this?
FWIW, the scaling issue goes both ways. Sometimes, an FT3 map will show a body of land being 100 miles across but CC3+ makes it 400 miles across. Other times, an FT3 map will show a body of land being 3,000 miles across but CC3+ makes it 500 miles across.
FWIW, the scaling issue goes both ways. Sometimes, an FT3 map will show a body of land being 100 miles across but CC3+ makes it 400 miles across. Other times, an FT3 map will show a body of land being 3,000 miles across but CC3+ makes it 500 miles across.
Comments
I don't think there is an actual relationship, but if its important to you that the export should be a certain size in CC3 you can always show all sheets, select all, and scale it larger, once you have it in CC3.
Not sure I've ever tried going the other way...
Another thing that throws a spanner into the works is map projection. FT3 does provide measurements correctly over a globe, while any export to CC3+ will be projected to a flat plane, which does cause some inaccuracies for the scale, since a sphere cannot be correctly represented on a flat plane.
That's because FT3 works (most usually) on a spheroid world and all the alternative projections, which distort distances in every direction and to different degrees depending on the projection, while CC3 makes no allowances for the curvature of a spheroid world and shows constant scale in all directions - as you would find on a flat world.
I'll try out your files when you attach them to see what I experience there. Will probably be tomorrow though, midnight is fast approaching.
(Don't know how to make the attachments feature work.)
FT3 file: go to the Nations: Seven Kingdoms view, get the N/S distance of the top middle body of water. Comes to around 600.
CC3+ file "Seven Kingdoms": The distance is around 90.
CC3+ file "raw test": The distance is around 900.
Maybe I did something in the "Seven Kingdoms" file to make it 10% the distance of the raw test (I made the map a year ago, I don't remember), but the raw test file shouldn't be producing distances 150% the size of the FT3 file. If anything the distances should be shorter, since it's not measuring along a curve.
So! The answer to the conundrum is to switch to a flat projection in FT3 *before* exporting to CC3+. You were of course right in your original comment!
Carry on.
http://desktop.arcgis.com/en/arcmap/10.3/tools/coverage-toolbox/choosing-a-map-projection.htm offers some suggestions for picking a map projection which will be a good compromise between the different kinds of distortions.
EDIT: and that's what I get for taking a long time to compose a message...
I was led astray because my original, worked-up map is *severely* off in scale, far more than would be explained by the differences in projections. But it looks like I must have done something to that one that scaled it down to 10% of its original scale, since the raw test map is 10x bigger in scale. But before I realized that problem it really did look like the scale was off, since even a switch from orthographic to a flat CC3+ map wouldn't have resulted in a change from 600 miles to 90.
Once I fixed that problem, the scale discrepancy got better, and then I noticed that my FT3 map was in orthographic.
Edit: and that's what I get for doing exactly the same thing, just now.
You can move the center of projection on your map by using the hand tool and holding down the Shift key (but I suspect that you already know that).