# Sagrada Familia Schools Roof

```d p = Point.ByCoordinates (Math.DegreesToRadians((0..(180*8)..10)),(-10..10..#9)<1>,(Math.Sin((-90..(180*8)..10)+(0..90..10)<1>)*(-1.25..1.25..#10))<1>); GeometryColor.ByGeometryColor(NurbsSurface.ByPoints(Point.ByCoordinates (p.X,(p.Z<-0.6 ? p.Y+(-p.Y*(p.Z)*0.08) : p.Y),p.Z)).Thicken(0.25).Translate(0,0,1.5),Color.ByARGB(255,255,250,200)); ``` While the code required to create this geometry can be packed into a couple of lines of Design, below is a stepwise elaboration of the process.

```d // Sine Wave r = 0..360; x = Math.DegreesToRadians(r); y = 0; z = Math.Sin(r); p = Point.ByCoordinates (x,y,z); ```

Step 2 : Decrease the point count, increase the wave frequency and amplitude

```d // Decrease point count r = 0..360..10; // Increase Frequency r = (0..360..10) * 4; // Increase Amplitude z = Math.Sin(r) * 1.5; ```

Step 3 : Multiple similar waves along the Y-axis

```d // A range of values along the Y-axis y = -10..10..#9; // Repeat waves along the Y-axis p = Point.ByCoordinates (x,y<1>,z); ```

```d // Nurbs Surface s = NurbsSurface.ByPoints(p); ```

Step 5 : Crest (from trough) at start of last wave

```d // Increase Z incrementally z = Math.Sin(r +(0..90..#9)<1>) * 1.5; // Apply to wave profiles p = Point.ByCoordinates (x,y<1>,z<1>); ```

Step 6 : Flattening amplitude towards the middle

```d // Incrementally minimizing amplitude of waves towards the middle a = List.Flatten([1.5..0..#4,0,0..1.5..#4],-1); z = Math.Sin(r +(0..90..#9)<1>) * a; ```

```d // Trough Protrusion tp = p.Z < -1.4 ? p.Y+(-p.Y*(p.Z)*0.1) : p.Y; pp = Point.ByCoordinates(p.X,tp,p.Z); ```

```d // Sine Wave r = (0..360..10) * 4; x = Math.DegreesToRadians(r); y = -10..10..#9; a = List.Flatten([1.5..0..#4,0,0..1.5..#4],-1); z = Math.Sin(r +(0..90..#9)<1>) * a; p = Point.ByCoordinates (x,y<1>,z<1>); // Trough Protrusion tp = p.Z<-1.4 ? p.Y+(-p.Y*(p.Z)*0.1) : p.Y; pp = Point.ByCoordinates(p.X,tp,p.Z); // Nurbs Surface s = NurbsSurface.ByPoints(pp).Thicken(0.25); ```