Abusing spirals

Toplogical Anomaly

Hello, I decided to mess around with some spirals now that my script is working.

Here it is again

module Spiral

  def self.make_circle_face(entities, circle_edges)
    pts = []
    circle_edges.each { |e|
      pts << e.vertices[0]
    face = entities.add_face(pts)
    return face

  def self.make_circle(entities, point, radius, normal)
    # make a circle face at the point with the given radius
    circ = entities.add_circle(point, normal, radius)
    circ_face = self.make_circle_face(entities, circ)
    return circ_face

  def self.draw_turns(entities, segments, radius, taper_amount, 
                        z, z_increment, facet_size, last_point, num_turns)
    (facet_size..(360 * num_turns)).step(facet_size).each do |angle|
      theta = angle.degrees
      radius -= taper_amount
      x = radius * Math.cos(theta)
      y = radius * Math.sin(theta)
      point = Geom::Point3d.new(x, y, z)
      line = entities.add_line(last_point, point)
      segments << line
      last_point = point
      z += z_increment

  def self.draw(radius, taper_amount, z_increment, num_turns, facet_size, segments)
    model = Sketchup.active_model
    entities = model.active_entities
    z = 0
    endpoint = Geom::Point3d.new(radius, 0, z)
    spiral_group = entities.add_group
    spiral_entities = spiral_group.entities
    self.draw_turns(spiral_entities, segments, radius, 
          taper_amount, z, z_increment, facet_size, endpoint, num_turns)
    return spiral_group
  end # method draw

end # module Spiral

radius = 100
taper_amount = 0.3
z_increment = 1
num_turns = 3
facet_size = 6
segments = []
wire_thickness = 20

model = Sketchup.active_model
model.start_operation('spiral', true)

  spiral_group = Spiral.draw(radius, taper_amount, z_increment, num_turns, facet_size, segments)
  entities = spiral_group.entities

  start_point = Geom::Point3d.new(radius, 0, 0)
  normal = [0,-1,0]
  face = Spiral.make_circle(entities, start_point, wire_thickness, normal)


  # begin abusing spiral
  stuff = spiral_group.explode
  curves = stuff.grep(Sketchup::Curve)
  curves.each { |c|
    points = c.vertices.map(&:position)
    points.each_with_index { |pt,i| 
      pt.z = pt.z * i
      pt.x = pt.x * i
      pt.y = pt.y * i

I decided to iterate through the curves and mess with the position of the vertices, resulting in this interesting shape here.

However I’m not sure why the faces became so patchy. (My husband immediately remembered a similar shape from Star Trek - pictured above.)

Is there a way to programmatically heal the faces so the object looks smooth again?

Thanks for any thoughts

1 Like

SketchUp does not like small faces. (It’s meant for modeling buildings.)
Try doing it at a larger scale.

Also, if interested in Spirals, @jimhami42 has spirixcode (google.com) available to learn from.

P.S. - That looks like the mobius / Tyken’s Rift episode from StarTrek:TNG.

Also, as you go deeper into coding for SketchUp, please realize that all of you modules should be inside one unique top-level namespace module. This separates all of your code and extensions from everyone else’s.