Turning a selection into a face?

tomot

the code snippet below asks the user to make a selection

model=Sketchup.active_model
	ents=model.active_entities
	sel=model.selection
    
    if sel.empty? 
      UI.messagebox("No selection !")
      return nil
    end

what code do I require to turn that selection into a face?

_____________ == Sketchup::Face

TIG

There are many ways, e.g.
sel.grep(Sketchup::Edge).each{|e|e.find_faces}
adds all possible faces edges in the selection...

tomot

@tig said:

There are many ways, e.g.
sel.grep(Sketchup::Edge).each{|e|e.find_faces}
adds all possible faces edges in the selection...

If I use the following statement:
$newface1=sel.grep(Sketchup::Edge).each{|e|e.find_faces}
the ruby console respond is:
%(#FF0000)[$newface1
[]]
I was expecting something like:
#Sketchup::Face:0xb3cb350

TIG

That method doesn't return faces, it just makes them !
To find them try...
` edges=sel.grep(Sketchup::Edge)
ofaces=[]
edges.each{|e|ofaces << e.faces}
ofaces.flatten!
ofaces.uniq!

edges.each{|e|e.find_faces}
nfaces=[]
edges.each{|e|nfaces << e.faces}
nfaces.flatten!
nfaces.uniq!The array 'nfaces' is all of the faces that are now attached to the edges - old and new. To find just the new faces try... faces=nfaces-ofaces`
Where 'faces' is the array of those...

tomot

I did not know that this is a 2 stage process, 1: find & 2: return

$newface1=sel.grep(Sketchup;;Face) #finds face only!
$newface1.pushpull $inset

So How do I implement a pushpull of $newface1?

TIG

First off...
Don't use $ variables !
If the vars are spread across different methods in the same class/module use @.
Otherwise why use them at all...
Try
newface1.pushpull(inset)
or
@newface1.pushpull(@inset)
Depending on the +/-ve value of the face it dictates the extrusion relative to the face.normal.
Note that the face.normal can be determined prior to the pushpull and then face.reverse! if it's the 'wrong orientation', for example you want the face to be 'down' so a +ve inset moves the pushpull down too then test face.normal.z<0, and if not you can use face.reverse! before the pushpull is done...

thomthom

@tomot said:

I did not know that this is a 2 stage process, 1: find & 2: return

$newface1=sel.grep(Sketchup;;Face) #finds face only!
> $newface1.pushpull $inset

So How do I implement a pushpull of $newface1?

sel.grep(Sketchup::Face)
This returns an array of all faces in the colletion (in this case selection)

<span class="syntaxdefault"><br />faces&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">sel</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">grep</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)&nbsp;}<br /></span><span class="syntaxcomment">#&nbsp;Push/pull&nbsp;all&nbsp;faces<br /></span><span class="syntaxdefault">faces</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">each&nbsp;</span><span class="syntaxkeyword">{&nbsp;|</span><span class="syntaxdefault">face</span><span class="syntaxkeyword">|&nbsp;</span><span class="syntaxdefault">face</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">pushpull</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">distance&nbsp;</span><span class="syntaxkeyword">)&nbsp;}<br />&nbsp;</span><span class="syntaxdefault"></span>

If you want only one entity, use find():

<span class="syntaxdefault"><br />face&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">sel</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">find&nbsp;</span><span class="syntaxkeyword">{&nbsp;|</span><span class="syntaxdefault">e</span><span class="syntaxkeyword">|&nbsp;</span><span class="syntaxdefault">e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)&nbsp;}<br /></span><span class="syntaxdefault">face</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">pushpull</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">distance&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;</span><span class="syntaxdefault"></span>

tomot

@tig said:

First off...
Don't use $ variables !
snip

I was using $ variables only to check what my face code was actually being selecting in the Ruby Console. I still trying to resolved this issue.

tomot

@thomthom said:

sel.grep(Sketchup::Face)
This returns an array of all faces in the colletion (in this case selection)

<span class="syntaxdefault"><br />faces </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> sel</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">grep</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">}<br /></span><span class="syntaxcomment"># Push/pull all faces<br /></span><span class="syntaxdefault">faces</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">each </span><span class="syntaxkeyword">{</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">|</span><span class="syntaxdefault">face</span><span class="syntaxkeyword">|</span><span class="syntaxdefault"> face</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">pushpull</span><span class="syntaxkeyword">(</span><span class="syntaxdefault"> distance </span><span class="syntaxkeyword">)</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">}<br /></span><span class="syntaxdefault"></span>

If you want only one entity, use find():

<span class="syntaxdefault"><br />face </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> sel</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">find </span><span class="syntaxkeyword">{</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">|</span><span class="syntaxdefault">e</span><span class="syntaxkeyword">|</span><span class="syntaxdefault"> e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">}<br /></span><span class="syntaxdefault">face</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">pushpull</span><span class="syntaxkeyword">(</span><span class="syntaxdefault"> distance </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault"></span>

That's precisely my problem in a larger nutshell , I'm trying to use RickW's offset.rb which draws a 2nd offset on the initial "sel" selected face. Since there now 2 faces I'm having difficulty selecting the offset face for pushpull that the offset.rb created, and NOT the initial "sel" selected face for pushpull. (I can post a pic if my description falls short)

Dan Rathbun

@tomot said:

I'm trying to use RickW's offset.rb which draws a 2nd offset on the initial "sel" selected face.

Please do not use that script AS IS. We need to put it on the Quarantine List.

It overrides the API Array#offset method, and adds methods to both API and Ruby Core base classes.

You can use ideas from the methods that do not change base classes (by re-writing them and putting them inside your own namespace.)

So... anyway Rick's offset method should have returned a reference to the added face, because it uses Entities#add_face()

To use that method inside youir OWN namespace, you need to pass a reference to the original face into the method, and replace all self references within the method to the reference name of the passed face argument.

Example 1 (The internals have not been changed much, but an undo operation has been added):

module Tomot
  module SomePlugin
    class << self

      def offset_a_face( face, dist )

        unless face.is_a?(Sketchup;;Face)
          fail(TypeError,"Sketchup;;Face instance expected for 1st argument",caller)
        end

        unless dist.is_a?(Numeric)
          fail(TypeError,"Numeric subclass expected for 2nd argument",caller)
        else
          if dist.zero?
            unless $VERBOSE.nil?
              puts("Tomot;;SomePlugin;WARNING; offset_a_face(); Offset distance was zero.")
            end
            return nil
          end
        end

        new_face = nil # this method's return value

        pi = Math;;PI
        verts = face.outer_loop.vertices
        pts   = []
        
        # CREATE ARRAY pts OF OFFSET POINTS FROM FACE
        
        0.upto(verts.length-1) do |a|
          vec1 = (verts[a].position-verts[a-(verts.length-1)].position).normalize
          vec2 = (verts[a].position-verts[a-1].position).normalize
          vec3 = (vec1+vec2).normalize
          if vec3.valid?
            ang = vec1.angle_between(vec2)/2
            ang = pi/2 if vec1.parallel?(vec2)
            vec3.length = dist/Math;;sin(ang)
            t = Geom;;Transformation.new(vec3)
            if pts.length > 0
              vec4 = pts.last.vector_to(verts[a].position.transform(t))
              if vec4.valid?
                unless (vec2.parallel?(vec4))
                  t = Geom;;Transformation.new(vec3.reverse)
                end
              end
            end
            
            pts.push(verts[a].position.transform(t))
          end
        end

        # CHECK FOR DUPLICATE POINTS IN pts ARRAY
        #
        duplicates = []
        pts.each_index do |a|
          pts.each_index do |b|
            next if b==a
            duplicates<<b if pts[a]===pts[b]
          end
          break if a==pts.length-1
        end
        duplicates.reverse.each{|a| pts.delete(pts[a])}

        # CREATE FACE FROM POINTS IN pts ARRAY
        #
        if pts.length > 2
          begin
            #
            if Sketchup.version.to_i > 6
              face.model.start_operation('Offset Face',true)
            else
              face.model.start_operation('Offset Face')
            end
              #
              new_face = face.parent.entities.add_face(pts)
              #
            face.model.commit_operation()
            #
          rescue
            face.model.abort_operation()
            raise() # to outer rescue clause
          end # begin
        end # if

      rescue TypeError

        raise() # just re-raise the Exception

      rescue => e # any other Exceptions;

        unless $VERBOSE.nil?
          puts("Tomot;;SomePlugin;WARNING; offset_a_face(); #{face.inspect} did not offset; #{pts}")
          puts("Error; #<#{e.class.name}; #{e.message}>")
          puts(e.backtrace) if $VERBOSE
        end
        raise() # re-raise to any debugger in use

      else # when no errors;

        return new_face

      end # offset_a_face()

    end # proxy class
  end # module SomePlugin
end # module Tomot

Dan Rathbun

Example 2 : Here is a shorter edition that uses a vector or an array as the 2nd argument, and leverages the API's built-in Geom::Point3d#offset! method.

You can create a vector to pass as the 2nd argument, or call the method with an array literal, to say, offset the face by 10 units in the positive Z direction:
offset_a_face( @face, [0,0,10.0] )

module Tomot
  module SomePlugin
    class << self

      def offset_a_face( face, vect )

        unless face.is_a?(Sketchup;;Face)
          fail(TypeError,"Sketchup;;Face instance expected for 1st argument",caller)
        end
 
        unless vect.is_a?(Geom;;Vector3d) || vect.is_a?(Array)
          fail(TypeError,"Geom;;Vector3d or Array expected for 2nd argument",caller)
        else
          vect = Geom;;Vector3d.new(*vect) if vect.is_a?(Array)
          if vect.length.zero?
            unless $VERBOSE.nil?
              puts("Tomot;;SomePlugin;WARNING; offset_a_face(); Offset vector length was zero.")
            end
            return nil
          end
        end

        new_face = nil # this method's return value

        verts = face.vertices

        # CREATE ARRAY pts OF OFFSET POINTS FROM FACE
        pts = verts.map {|v| v.position.offset!(vect) }

        # CREATE FACE FROM POINTS IN pts ARRAY
        #
        if pts.length > 2
          begin
            #
            if Sketchup.version.to_i > 6
              face.model.start_operation('Offset Face',true)
            else
              face.model.start_operation('Offset Face')
            end
              #
              new_face = face.parent.entities.add_face(pts)
              #
            face.model.commit_operation()
            #
          rescue
            face.model.abort_operation()
            raise() # to outer rescue clause
          end # begin
        end # if

      rescue TypeError
 
        raise() # just re-raise the Exception

      rescue => e # any other Exceptions;

        unless $VERBOSE.nil?
          puts("Tomot;;SomePlugin;WARNING; offset_a_face(); #{face.inspect} did not offset; #{pts}")
          puts("Error; #<#{e.class.name}; #{e.message}>")
          puts(e.backtrace) if $VERBOSE
        end
        raise() # re-raise to any debugger in use

      else # when no errors;

        return new_face

      end # offset_a_face()

    end # proxy class
  end # module SomePlugin
end # module Tomot

Dan Rathbun

Example 3 : a one-liner (with no error trapping, etc.)

Assume @vect is either an Array or a Geom::Vector3d instance:

@nface = @oface.parent.entities.add_face(@oface.vertices.map {|v| v.position.offset!(@vect) })

thomthom

@tomot said:

That's precisely my problem in a larger nutshell , I'm trying to use RickW's offset.rb which draws a 2nd offset on the initial "sel" selected face. Since there now 2 faces I'm having difficulty selecting the offset face for pushpull that the offset.rb created, and NOT the initial "sel" selected face for pushpull. (I can post a pic if my description falls short)

<span class="syntaxdefault"><br />model&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_model<br />entities&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">model</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_entities<br />sel&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">model</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">selection<br /><br /></span><span class="syntaxcomment">#&nbsp;Grab&nbsp;a&nbsp;list&nbsp;of&nbsp;existing&nbsp;faces<br /></span><span class="syntaxdefault">original_faces&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">entities</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">grep</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)<br /><br /></span><span class="syntaxcomment">#&nbsp;First&nbsp;offset&nbsp;face<br /></span><span class="syntaxdefault">face&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">sel</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">find&nbsp;</span><span class="syntaxkeyword">{&nbsp;|</span><span class="syntaxdefault">e</span><span class="syntaxkeyword">|&nbsp;</span><span class="syntaxdefault">e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)&nbsp;}<br /></span><span class="syntaxdefault">offset</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">face</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">20.mm&nbsp;</span><span class="syntaxkeyword">)&nbsp;</span><span class="syntaxcomment">#&nbsp;I&nbsp;don't&nbsp;know&nbsp;what&nbsp;the&nbsp;real&nbsp;method&nbsp;is&nbsp;there.<br /><br />#&nbsp;Then&nbsp;Push-pull&nbsp;inner&nbsp;face<br /></span><span class="syntaxdefault">faces&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">entities</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">grep</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)&nbsp;-&nbsp;</span><span class="syntaxdefault">original_faces<br />inner_face_from_offset&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">faces</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">first&nbsp;</span><span class="syntaxcomment">#&nbsp;*should*&nbsp;be&nbsp;just&nbsp;one&nbsp;face<br /></span><span class="syntaxdefault">inner_face_from_offset</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">pushpull</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">500.mm&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;</span><span class="syntaxdefault"></span>

Untested

Dan Rathbun

@thomthom said:

I don't know what the real method is there.

It was my Example 1 (above) but Rick's edition was an instance method added to the Sketchup::Face class. (I re-wrote it to pass the face instance into the method.)

As shown in my one-liner (Example 3) a method is not really even needed.
@oface is the old face in the selection.
The new face will be @nface, and then just do the push-pull on it.

thomthom

@dan rathbun said:

Example 3 : a one-liner (with no error trapping, etc.)

Assume @vect is either an Array or a Geom::Vector3d instance:

@nface = @oface.parent.entities.add_face(@oface.vertices.map {|v| v.position.offset!(@vect) })

That just offsets in an direction - we're talking about offsetting in terms of what the Offset tool does.

tomot

Tig, thomthom and Dan, thanks for your input it will take me a few days to digest your input, and try putting your input into use.
but thomthom is right, I'm looking for the statement that allows me to offset the face the offset.rb creates.

I was hoping a simple Boolean expression in the API would have served a very useful purpose, in this particular instance.

Dan Rathbun

@tomot said:

... but thomthom is right, I'm looking for the statement that allows me to offset the face the offset.rb creates.

OK... then first of all the Example 1 re-write of Rick's method mimics the native offset tool, and returns the newly created offset face.

(Just ignore Examples 2 & 3, as I did not understand what was needed and may have misunderstood what Rick's code was doing.)

If you wish to AGAIN apply an offset, pass the newly created face and a new offset distance (or whatever distance,) into the method a second time.

If you wish to move it or something else ... do whatever by using the returned reference as needed.

Here is test script wrapped as Tomot::Offset, that adds right-click mouse "Offset Face" commands to the popup menu, but differs in result from the native tool by setting the selection to the new face. (The native tool does not change the selection set.) It also uses an inputbox to get the distance, ... but in practice you would bypass that and your code would supply the needed distance value.

module Tomot
  module Offset
    class << self

      def offset_a_face( face, dist )

        unless face.is_a?(Sketchup;;Face)
          fail(TypeError,"Sketchup;;Face instance expected for 1st argument",caller)
        end

        unless dist.is_a?(Numeric)
          fail(TypeError,"Numeric subclass expected for 2nd argument",caller)
        else
          if dist.zero?
            unless $VERBOSE.nil?
              puts("Tomot;;Offset;WARNING; offset_a_face(); Offset distance was zero.")
            end
            return nil
          end
        end

        new_face = nil # this method's return value

        pi = Math;;PI
        verts = face.outer_loop.vertices
        pts   = []

        # CREATE ARRAY pts OF OFFSET POINTS FROM FACE

        0.upto(verts.length-1) do |a|
          vec1 = (verts[a].position-verts[a-(verts.length-1)].position).normalize
          vec2 = (verts[a].position-verts[a-1].position).normalize
          vec3 = (vec1+vec2).normalize
          if vec3.valid?
            ang = vec1.angle_between(vec2)/2
            ang = pi/2 if vec1.parallel?(vec2)
            vec3.length = dist/Math;;sin(ang)
            t = Geom;;Transformation.new(vec3)
            if pts.length > 0
              vec4 = pts.last.vector_to(verts[a].position.transform(t))
              if vec4.valid?
                unless (vec2.parallel?(vec4))
                  t = Geom;;Transformation.new(vec3.reverse)
                end
              end
            end

            pts.push(verts[a].position.transform(t))
          end
        end

        # CHECK FOR DUPLICATE POINTS IN pts ARRAY
        #
        duplicates = []
        pts.each_index do |a|
          pts.each_index do |b|
            next if b==a
            duplicates<<b if pts[a]===pts[b]
          end
          break if a==pts.length-1
        end
        duplicates.reverse.each{|a| pts.delete(pts[a])}

        # CREATE FACE FROM POINTS IN pts ARRAY
        #
        if pts.length > 2
          begin
            #
            if Sketchup.version.to_i > 6
              face.model.start_operation('Offset Face',true)
            else
              face.model.start_operation('Offset Face')
            end
              #
              new_face = face.parent.entities.add_face(pts)
              #
            face.model.commit_operation()
            #
          rescue
            face.model.abort_operation()
            raise() # to outer rescue clause
          end # begin
        end # if

      rescue TypeError

        raise() # just re-raise the Exception

      rescue => e # any other Exceptions;

        unless $VERBOSE.nil?
          puts("Tomot;;Offset;WARNING; offset_a_face(); #{face.inspect} did not offset; #{pts}")
          puts("Error; #<#{e.class.name}; #{e.message}>")
          puts(e.backtrace) if $VERBOSE
        end
        raise() # re-raise to any debugger in use

      else # when no errors;

        return new_face

      end # offset_a_face()
      
      #{ get_dist(face)
      #
      #  Prompts for a distance, then calls offset_a_face()
      #  If a new offset face is created, it will be set as
      #    a single object of the current model's selection.
      #
      def get_dist(face)
        result = UI.inputbox(['Offset distance ;   '],[0],'Offset a Face')
        if result
          ret = offset_a_face(face,result[0])
          if ret
            sel = Sketchup.active_model.selection
            sel.clear
            sel.add(ret)
          else
            return nil
          end
        else
          return nil
        end
      end #}

    end # proxy class

    unless file_loaded?(File.basename(__FILE__))

      UI.add_context_menu_handler {|popup|
        unless Sketchup.active_model.selection.empty?
          sel = Sketchup.active_model.selection
          if sel.single_object? && sel[0].is_a?(Sketchup;;Face)
            face = sel[0]
            popup.add_item('Offset Face',10) { get_dist(face) }
          else
            face = sel.find {|o| o.is_a?(Sketchup;;Face) }
            if face # (nil if no face was selected)
              popup.add_item('Offset First Face',11) { get_dist(face) }
            end
          end
        end
      }

      file_loaded(File.basename(__FILE__))

    end

  end # module Offset
end # module Tomot

Question to the room at large: Regarding line 137, which is faster for large selection sets ?
face = sel.find {|o| o.is_a?(Sketchup::Face) }
OR
face = sel.grep(Sketchup::Face)[0]

Keep in mind both need to be fololowed by a nil test conditional, viz:
if face

tomot

Dan thanks for your code, however regarding your last piece of code.
I'm unclear as to how to use it.

If I save your code as as offset.rb and replace it with the original offset.rb then load it in the console, I get an error in the console when I right click on selected face.

Is this the way you intended it to be used? Please explain further!
and just to make sure, please see the attachment regarding the face in question.

Dan Rathbun

YES, make a selection, then right-click the selection (or a single face,) and an inputbox should pop up to enter a distance.

IF you get an error, it would help if you paste the error message into a post.

tomot

@dan rathbun said:

IF you get an error, it would help if you paste the error message into a post.

there is also no "offset" reference in the context menu