So I want make a mortar in Bl1, who can tell me how to calculate the parabola? (Means how to calculate by mortar it self) Pls give a calculation process to me Thank you!

Does your projectile have to be a non-physics object? I would go with the easier physics route The equation for a parabola is the quadratic formula, you can search that up... Should you desire to attempt this, realize

Oh,I think I already got how to make a mortar.i just have to try a right angle. Thank you.. ...Also your lever Dropbox also very good! Just the spiked is used from others lever, so I hope you can create your own group to make lever better.