I need to create a 3d datum curve, but one of my curves is created through an equation. Before, I just used a 2 Projection datum curve and sketched the independent curves to form the 3d curve. I can't figure out how to do this with equations instead. When I use this 2 projection feature, it automatically asks me to pick a sketching plane and there is no option for an equation. Does anyone know how to do this?