Reference:Spiral1 Pattern

The spiral1 pattern creates a spiral that winds around the z-axis similar to a screw. When viewed sliced in the x-y plane, it looks like the spiral arms of a galaxy. Its syntax is:

pigment {
  spiral1 Number_of_Arms
  [PIGMENT_MODIFIERS...]
  }

The Number_of_Arms value determines how may arms are winding around the z-axis.

As a normal pattern, the syntax is

normal {
  spiral1 Number_of_Arms [, Bump_Size]
  [NORMAL_MODIFIERS...]
  }

where the Number_of_Arms value is a required parameter but the float Bump_Size which follows is optional.

Note: The comma is required especially if Bump_Size is negative.

The pattern uses the triangle_wave wave type by default but may use any wave type.