Ok, so I am drawing a spline with the "create line", and I want it to be on a single X-Z plane. I am drawing from ortho front view, and so my viewport is aligned in an X-Z plane.
I am snapping to something in my model space to determine the Y depth. Let's say I want my Y depth to be 10 units. I hold shift, after snapping the first starting point off of pre-existing model geometry known to be at Y depth 10 units, and I want to draw a vertical line down. I do so by holding shift to constrain the line to the vertical Z axis on screen. In front view ortho, all looks well. When I enter perpective, everything is fine, except that I have actually drawn the second point with every correct coordinate, except its Y is now 0- it has snapped to the X-Z plane who's Y depth is 0, instead of 10, and effectively I have a diagonal line instead of a vertical one. This is a very annoying functionality to me so far. Every point that I draw after that on that line will be in the same plane, but with a Y value of 0 now.
How do I set things so that when I am in that front view, I don't snap to the Y-origin 0 plane? The axial and plane snaps don't seem to have an effect of this tendency.
If there is no direct work-around, can I temporarily reset my origin so that my new Y-0 is on the plane I want to work on?
Thanks in advance, and I think there will be many more questions as I transition to 2014 from a much earlier interface (Viz). I have of course searched the help materials, and no obvious direct answer to this issue jumped out to me.
Depends, at least in part, on how your Snaps are set.
2D - will only snap to existing objects (or sub-objects) which are at 0 i.e. on the construction plane, based on the current view. All objects are created on the construction plane i.e. at 0.
2.5D - will snap to objects not at 0 but will still create new objects on the construction plane.
3D - will snap to objects not at 0 and will create new objects at that snapped-to location.
Your best bet would probably be to create a Grid Helper, position and rotate it as necessary. Right-click with the grid selected and Activate it. Click the "Front" viewport label > Extended Viewports > Grid > Top. Then create your line - it will be created flat on that grid object.
It took me a couple minutes to figure out what helper grids were, but I think it is a pretty solid answer to the question.
Those grids allow me to snap my 2D drawing splines to a plane other than the 0 construction plane, which is what the original issue was.
This link explains the concept to anyone who has the problem in the future: