How to draw an aspheric curve How to draw an aspheric curve Sag equation 𝑧= 𝑥2 𝑅 + 𝑅2 − (1 + 𝑘)𝑥 2 R : Radius of curvature k : Conic constant Example (R=100, k=-0.9) x^2/(100+sqrt(100^2-(1-0.9)*x^2)) Starting point to draw aspheric curve in local coordinate of the curve End point to draw aspheric curve in local coordinate of the curve Blue color curve!! This is local coordinate Local coordinate for the curve !! Local coordinate of the sketch plane Global coordinate Global coordinate How to draw an aspheric curve Cautions!! • Please check all coordinates after you draw. • Please make your curve be fully defined in dimension. In other words, make it be black!! Use ‘fix’!!