Linear Extrude with Twist as an interpolated function

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OpenScad Linear_Extrude Extended Use Example Module and Function Example to Make Linear_extrude Twisting Functionality Follow a Function It Is a Piecewise Union of Linear_extrudes The Example Uses a Sine Function as a Twisting Function Scaling by a Scalar Is Incorporated and Can Also Be Passed to the Module. How I Designed This In an Attempt to Emulate a Propeller Blade with an Aerofoil Profile, I Wanted to Define a Progressive Increment and Decrement of the Blade Width, Maintaining the Profile As Moving from Root to Tip of the Blade. The Twist Part Was a Follow Up Once I Managed to Get the Scaling Section Done. Main Code Module Linear_extrude_ft(height=1,isteps=20,scale=1,slices=0){ Union(){ For(i = [ 0: 1: isteps-1]){ Translate([0,0,iheight/isteps]) Linear_extrude( height=height/isteps, twist=f_left((i+1)/isteps)-f_left((i)/isteps), scale=(1-(1-scale)(i+1)/isteps)/(1-(1-scale)i/isteps), slices=slices ) Rotate([0,0,-f_left(i/isteps)]) Scale(1-(1-scale)(i/isteps)) Obj2D_left(); }}} User Must Implement a Function with the Name function f_left(x) =...; Which Returns the Value of the Twist with an Expected Input Ranging from 0 to 1 Along the Extruded Height. User Must Also Implement a Module Named module obj2D_left(){...} to Define the 2 Dimensional Object to Extrude.