Lofting surfaces from cross sections

- At this stage, we have a series…of circular cross-sections,…representing this rear-triangle element.…We now need to move them up…in the z direction to various heights…to represent the 3D curvature of this element.…You see, this part of the frame…has to start at the seat-tube,…and it has to bend up around the rear-tire,…and go over here to some height above the ground.…So, to help us visualize…this rather complex 3D situation,…let's draw in a few lines.…

Zoom in here and draw a line…at the end-point of the yellow, curved path.…Draw it straight up, 70 mm in height.…Type "70", "enter", "enter",…then continue drawing the line.…So just press "enter", "enter", to continue,…then come over here and snap it…to the opposite end of the curved path.…And then, complete the picture by snapping…another line back to where you started from.…

So now we have a triangle.…Let's go ahead and change the UCS to match up…with this triangle, which defines a plane.…Type "UCS", "enter",…click the origin point right here,…click the second point right here,…