sub simple_properties {
  my %properties = %{ shift() };
  my ($emissive, $diffuse, $shininess, $specular, $transp);
  foreach my $property (keys %properties) {
    if ($property eq "emissive") {
      $emissive = "emissiveColor  @{$properties{ $property }} ";
    }
    elsif ($property eq "diffuse") {
      $diffuse = "diffuseColor  @{$properties{ $property }} ";
    }
    elsif ($property eq "shininess") {
      $shininess = "shininess  @{$properties{ $property }} ";
    }
    elsif ($property eq "specular") {
      $specular = "specularColor  @{$properties{ $property }} ";
    }
    elsif ($property eq "transparency") {
      $transp = "transparency  @{$properties{ $property }} ";
    }
  }
  return <<"EOR";
appearance Appearance {
  material Material {
    $emissive
    $diffuse
    $shininess
    $specular
    $transp
  }
}
EOR
}