I'm currently designing a transit diagram in Illustrator CC, but I'm having some trouble with snapping. I'm working on a grid with snapping on, with 10px stroke paths. An example of my problem is as follows: I have a 90 degree path laid out and I go to make a 45 degree diagonal off it using the shift key, but the end of that new diagonal ends up on a half pixel. See the picture below:
You'll see the end of the path on the right is at X 630.5 and Y 185.5. I'm working on a 10px grid with 10 subdivisions. How can I make it so it snaps to whole pixels only, this is really infuriating!
You said you created it using the shift key - now when you take geometry into account, is it even possible that the path is at a whole pixel in this position?
I mean: if you force it onto the whole pixel, will the path segment still be at 45° angle?
Have you tried moving the endpoints (instead of grabbing the center of the line)? It seems like Illustrator doesn't know how to act when you move an entire line (instead of a single endpoint).