Persistent spline width? (3D Rendering Q)

[Sketchasaurus]

It's similar, but I want objects to be capable of being projected in perspective, but for splines to have a consistent width when rendered.

Here's a mock-up of what I mean. (animated in flash to illustrate what I'm trying to say)

Notice how the lines remain the same width regardless of the distance to the "camera" while still retaining the ability to show things in perspective.