In Bryce, while nothing is selected go to the menu and under “Objects” select “Create Path” or simply press “Alt + P” (Windowz). This will create a standard sign curve path for you. While the path is selected you can add vertices to it by holding down the “Alt” key and clicking on the path where you want the new vertex to go. Hovering your mouse cursor over the individual vertex and moving it to where you need it can reposition these vertices. Don’t forget that you can view and move the vertices in 3D depending on which screen view you choose. The same can be done with the preset paths.

Quest