Create a route based on 2 points, does BaseCamp add a 3rd point? Can someone verify?

Thanks for the reply. I can understand on the confusion. I am working with someone that uses BaseCamp to input routes into their Garmin GPS and typically uses routes. We are looking to verify a few new coordinates, so yes the main thing I want is a straight line between two waypoints to visualize in BaseCamp how this new coordinate aligns to existing boundaries.

I've done as you said created routes based on 2 points, but while the routes are created I'm observing strange behavior and believe the software adds an additional point to the route when it is created.

For example, I create a route and then I invert the route and now the route is different or moves about 30 feet either east or west from the original route I created. If a route is between two points shouldn't it be the same whether it starts at point 1 or point 2?

I've also noticed that if I create a track from my route, the track then shows an extra mid-point inserted between the two original waypoints. I've attached screenshots. This is misleading on the route and comparing with existing boundaries because if I remove the middle point inserted by the software this impacts the line and its path/relationship to adjacent boundaries. 

Lastly there is a window if you try and create a route that shows up. Can someone clarify on what this asking? To me its asking how many additional points I want to create in the route between my original 2 points. I only want a start and end point. This will be input for a GPS for flying over the boundary. However if the software is adding in a 3rd point when it creates a route, this is not something I want but I do want to verify.

I do not understand why the route between two points would be different based on its direction (inverted). I also do not understand on that additional point that shows up.

You're making life difficult for yourself and as I'm not looking over your shoulder it's difficult to follow exactly what you're doing, and there are too many variables to make a guess.  If you simply want a straight track or route then a track will go where you want it, as will a route if you select direct activity. Now, the real point is how this will work when you transfer it to your device, but as you don't mention which device I can't advise further until I know.

I've selected direct activity for the route. I'm just trying to troubleshoot the issues we are seeing in the software itself and different routes that are showing. My work is not difficult, I'm trying to create a direct line between two waypoints. So why is that route different depending which starting point I use or invert it. The route moves 30 feet to the east or west? 

The 30 feet might not seem like a big deal but if the software is adding a 3rd point when it creates a route this could be what is causing a 60 foot shift in the line compared with the other mapping software I use. (Esri desktop software).

I don't what know what GPS unit the field crew is using, I'm just trying to help understand these differences we are seeing in the BaseCamp software.

Currently I do not understand the differences on the lines the software is creating. For instance if anybody else created a route between two points convert it to a track, there will likely be an extra point as I showed earlier. This is actually really important because the trajectory of the line will be different over a 17 mile distance we are looking at.

I'm not trying to make it difficult but I need to understand what the software is doing. A route if it truly consisted of only two points when inverted shouldn't move east or west of the original route. I appreciate your insights.

Seeing the initial Route Properties window would be helpful.  When you made the initial Route with the Direct profile you should have seen only two points in listed in the Route Properties window (ignore the summary area).  If you click on the Directions tab, you should only two points.  Is this what you see?

The creation of a track from this route will add a point between the start and finish.  The middle point can be deleted from the Track Properties window by selecting it and pressing the delete key or using the eraser tool on the map.  Or you could click on the filter key and set a maximum number of points to 2.

I'm not clear on what you are seeing when you mention the shift.  When Garmin devices or BaseCamp calculates a distance or course it is using a Great Ellipse calculation.  I would not be surprised that when they added the point to the Track that this point is somewhere along the Great Ellipse arc between the start and finish points you provided.  To put it another way, the added point is not on a direct compass heading between the start and finish point.

I am guessing the shift you mentioned refers to the three point tracks made from two routes where the start and finish points were reversed.  Since the point added during Route to Track conversion is not midway between the start and finish, if the point is on the Great Ellipse arc, you might see a shift in the two 3-point tracks.  But, as I wrote earlier, just delete the middle point and you will be fine.

Regarding the Track Conversion options, recorded tracks can contain up to 10,000 points.  Routes on Garmin devices are limited to far fewer points, so culling is necessary if you wish to use the converted route on a Garmin device.

Thanks so much for the great info. A little more info for why the difference matters, is I'm trying to see how close a route/track line is to an existing line that includes the point.

My process, I create a new route based on the lat/long shown in the route properties in the screenshot below. The properties do show only 2 points and the new route displays.

Without converting the new route to tracks, I click 'Invert' and this moves the route approximately 30 feet to the west. The original route is shown in pink.

Next I create a track from that inverted route. You are correct I do see now 3 points with the new one in the middle. But the track shows the same as the inverted route.

I delete the middle point from the tracks and you would think this would look now like one of the routes? The track properties show only two points, but now my track line shifts another 30 feet and actually is where I would have thought it should align based on the other GIS mapping software I use.

Now when I click to invert the track line, the track line does not shift, but just the direction as you would expect from a line based on only 2 points.

Now the track line properties and route properties look the same with only those 2 points showing, but based on what I see here I would only trust the track line. The route even though it does not show an extra point must have it which would explain the offset routes depending on which starting point of the route. The original route and is ~60 feet east of the track line. The yellow line is the inverted route and is ~ 30 feet from the track line.

Thanks so much again and this has definitely been a learning process. I look forward to any other insights/findings you have.

While this is no doubt an interesting discussion about what is happening when you take certain steps I do feel you're overcomplicating it. It would also help if you said which device you want to use it on, as some can't even accept tracks so you would need to stick to routes. 

I will find out on the device. All I know is we are trying to figure out differences in the how the software creates the routes since this is a typical/desired workflow to use for field work planning/navigation. When verifying features on the ground the software showing differences of being of ~30 - 60 feet is important to understand why. For instance, why should there be any difference in a route depending on which direction it is created. This would be really good info to relay to the field crew. I will follow up on the device, but I would appreciate further info on differences we are seeingin the software itself and route/track accuracies, this is really important as well.