This plugin allows you to add new points just like the LW builtin '+' except the points are placed directly on the polygons you have in your BG layers. You can place them in any viewport, including the perspective viewport, and the point will appear directly under your mouse pointer, but snapped in depth to BG polygons. Just like with the '+' builtin, you can move the points around with the left mouse button and clone more off with the right. It works best if the BG layer contains planar polys (so to be safe, triangulate everything first).
Download here (LW7.5, PC) (12k)
How to use
This plugin lets you move points around like the LW builtin 't' except the points stay on the surface of the polygons you have in your BG layers. Again, you can move them in any viewport, and they will roughly follow your mouse pointer around, but snapped to the surfaces you have in your BG layer. The points drift a little in perspective mode, but not enough to affect performance, in my opinion. Obviously dragging points on and off of surfaces very oblique to your view angle can move them closer to or further from each other in world space, even though they may look the same in screen space. Like addPointOnBG, it works best if the BG layer contains planar polys (so to be safe, triangulate everything first).
Download here (LW7.5, PC) (13k)
How to use
Dario used my plugin in a tire modeling tutorial. He lathes out a smooth tire, throws it in the BG layer, draws the tread pattern on a plane and then snaps it to the smooth tire shape with this plugin.