GetUVs.rb

require 'stringio'

output = StringIO.new
model = Sketchup.active_model
tw = Sketchup.create_texture_writer
model.selection.grep(Sketchup::Face) { |face|
  tw.load(face, true)
  uvh = face.get_UVHelper(true, true)
  uvh_tw = face.get_UVHelper(true, true, tw)
  output.puts ""
  output.puts face
  face.vertices.each { |vertex|
    uvq = uvh.get_front_UVQ(vertex.position)
    uvq_tw = uvh_tw.get_front_UVQ(vertex.position)
    uv = Geom::Point3d.new(uvq.x / uvq.z, uvq.y / uvq.z, 1.0)
    output.puts "> #{vertex} (#{vertex.position.inspect})"
    output.puts "  > UV:  #{uv.inspect}"
    output.puts "  > UVQ: #{uvq.inspect}"
    output.puts "  > UVQ (TW): #{uvq_tw.inspect}"
  }
}
puts output.string
nil

Result.txt

#<Sketchup::Face:0x0000000ad31008>
> #<Sketchup::Vertex:0x0000000c423a40> (Point3d(21.1805, 25.7197, 15.0663))
  > UV:  Point3d(0.761389, 0.618252, 1)
  > UVQ: Point3d(-7.19346, -5.84112, -9.44781)
  > UVQ (TW): Point3d(1, 0, 1)
> #<Sketchup::Vertex:0x0000000c423ab8> (Point3d(27.2152, 19.685, 27.8389))
  > UV:  Point3d(0.76863, 0.530675, 1)
  > UVQ: Point3d(-7.26189, -5.01373, -9.44783)
  > UVQ (TW): Point3d(0.882683, 1, 1)
> #<Sketchup::Vertex:0x0000000c43ad08> (Point3d(36.2468, 25.7197, 27.8389))
  > UV:  Point3d(0.832569, 0.527163, 1)
  > UVQ: Point3d(-7.86597, -4.98055, -9.44783)
  > UVQ (TW): Point3d(0.117317, 1, 1)
> #<Sketchup::Vertex:0x0000000c459910> (Point3d(32.9808, 33.6045, 15.0663))
  > UV:  Point3d(0.844929, 0.613663, 1)
  > UVQ: Point3d(-7.98273, -5.79778, -9.44781)
  > UVQ (TW): Point3d(0, 2.1476e-008, 1)