Randomly position textures on faces in SketchUp

random_texture_pos.rb

# Randomly position textures on faces
# To begin, select ungrouped faces and/or grouped objects, not components

mod = Sketchup.active_model # Open model
ent = mod.entities # All entities in model
sel = mod.selection # Current selection

# Get all ungrouped faces and those that are inside groups (from selection)
all_faces = []

  # Ungrouped faces first
  all_faces.push( *sel.grep( Sketchup::Face ) )
  
  # Grouped faces next
  sel.grep( Sketchup::Group ).each { |g|
    g.make_unique  # Need to do this, otherwise group copies share same definition
    all_faces.push( *g.entities.grep( Sketchup::Face ) )
  }

# Iterate through all faces and randomly arrange the textures
all_faces.each { |f|

  pt_array = []
  pt_array[0] = f.vertices[0].position
  
  # Radomly scale based on face size
  pt_array[1] = Geom::Point3d.new(rand * f.bounds.width,rand * f.bounds.height,0)
  
  # Arrange both the front and the back face textures
  f.position_material(f.material, pt_array, true)
  f.position_material(f.back_material, pt_array, false)
  
}