Hi KMercier,
Thank you for your recommendation and I had also made reference to your previous reply (the BlockWall.zip)
https://forums.autodesk.com/t5/civil-3d-forum/sac-marked-points/td-p/3188240
Agreed that number of “Decision” should be added for creating the Shape. In actual, the total number of Shape was affected by the Height of Fill [L2], Slope Surface [AL3] and Inclination [AL4]. The pkt revised and worked fine!
Right now, in C3D, error “Object reference not set to an instance of an object” appeared for several chainage if 0.05m was input for Height L2, but free of error for Height larger than 0.05m. How could I solve this issue?