Adjust normal length with ramp, extrude along normal in Houdini

Adjust normal length with ramp, extrude along normal

(to create an arc with different diameters) add circle primitive type: polygon arc type: open arc divisions: 50 add clip node (to clip the circle in half) direction: 0 1 0 (make sure points numbers start from 0 at beginning of curve) add resample node check curve u attribute curveu add polyframe node uncheck normal name uncheck tangent name check bitangent name N check make frame orthogonal (to make the normals points inwards) add attribute wrangle node @scale = chramp("z_scale", @curveu); @N *= @scale; then click spare parameters icon add poly extrude node extrusion mode: point normal existing distance: 0.15