One particular feature of the Curve SOP that I CONSTANTLY find myself to require is an ability of the curve to adhere to some projection surface. In other words, I'd like to be able to pipe a projection surface to Curve SOP's, currently nonexistent, second input in order to have its points to be immediately projected on the surface, along with the curve itself.

I am fully aware that I can project the curve on the surface with the Ray SOP downstream, or draw a curve with Draw Curve SOP and then resample it, but it's not the same as creating points of the curve and have the curve to be immediately projected on-the-fly.

Here's a demo of the behavior that I'm looking for, from a video that I created some time ago for other software. Ignore the polygons created from the curves as they're irrelevant to this subject. Note how the curve between the points nicely follows the projection surface in real-time.

0:15 to 0:24
https://youtu.be/wyqukJQPFU8?t=14 [youtu.be]

Of course, the projection should also apply not only for the Curve SOP in Draw Mode, but also in Select/Edit Mode.

Has someone perhaps already came up with an HDA that addresses this (maybe via modification of the Draw Curve SOP)? Are there any existing tools that implement it? Is this planned for the future?