I have two shapes, in this case red and dark blue circles (for clarity), that I want smoothly connected by a tangent line and eventually united into a single, monocolor shape path.
I am using the 'Tangent Line Tool' from the Astute Graphics SubScribe v2 plugin to create my tangent line between my two shapes (I've also tried this manually and using another free Common Tangents plugin, and I run into the same issue.)
So, I create my tangent line (green with thick stroke for illustrative purposes) between the red circle and dark blue circle. I've highlighted the endpoints of the line in light blue. So far so good, outline looks pretty precise to the naked eye and is the tangent I want.
In order to unite the shapes using the pathfinder, I'll need to turn the tangent line into a shape, it can't just be a line, so I do that. Leaving the original endpoints of the tangent line exactly where they were, I connect the end points of the tangent line by making two new points, thereby creating an arbitrary square shape with the Pen Tool.
I zoom in as much as I can on the tangent line point that overlaps with the red circle; so far all the points are where I left them and look OK.
Now here's where my problem arises. I hit Unite in the pathfinder to join the red circle with my green square, expecting Illustrator to make a nice clean monocolored shape leaving my points exactly where they were, then BAM, the shapes unite but Illustrator has for some reason shifted the shapes before uniting/created two points and nudged them away from the original point position, dirtying up my nice clean shape path. See the issue highlighted below in light blue circle.
Using the Shape Builder Tool also results in the same problem.
Snap to grid, snap to pixel grid, snap to point, etc. are all off, and it doesn't seem to matter whether I'm working in a web or print doc, or in pixels, points, or otherwise.
I know I could just fill in the tangent shape the same color as the entire shape I'm making and leave things overlapping, but I won't have a nice single, clean shape path.
Is there any way to get around this? Any insight is highly appreciated.