Move points to a '3D grid'

rossthompson · 26 Mar 2012, 11:10

Hi,

I am trying to write a script for cleaning up geometery created from another program (IES VE). Essentially what I want to achieve is to move each vertex so it sits on a '3D grid'. I believe this could be achieved by applying a rounding function to the X,Y and Z coordinates of each point.

The attached image hopefully illustrates what I am trying to achieve. Ideally the degree of rounding would be a user input variable.

Any help on this would be greatly appreciated.

Ross

gilles · 26 Mar 2012, 11:51

You can use the scale tool: begin to scale then type 400mm;400mm;400mm + enter.

Note that the separator may be "," for you .

thomthom · 26 Mar 2012, 11:57

@gilles said:

You can use the scale tool:

@rossthompson said:

I am trying to write a script

thomthom · 26 Mar 2012, 12:01

This is a nice idea - I might implement such a feature in Vertex Tools.

Of the top of my head, something like this:

pt = Geom::Point3d.new( 3.976879, 3.970209, 1.002568 ) grid_pt = pt.to_a.map { |n| n.round() } v = pt.vector_to( grid_pt )

You can do something like that - iterate the vertices of a mesh, for each vertex find the nearest grid position to the vertex, collect the vertex and adjustment vector to each their array and use Entities.transform_by_vectors https://developers.google.com/sketchup/docs/ourdoc/entities#transform_by_vectors

Note that this simple example rounded to nearest whole number. Modifications is needed to account for grids fitted to decimal precision.

thomthom · 26 Mar 2012, 12:01

Actually, that example will round to nearest inch - which is SketchUp's internal unit...

thomthom · 26 Mar 2012, 12:15

<span class="syntaxdefault">pt </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> Geom</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Point3d</span><span class="syntaxkeyword">.new(</span><span class="syntaxdefault"> 3.976879</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m</span><span class="syntaxkeyword">,</span><span class="syntaxdefault"> 3.760209</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m</span><span class="syntaxkeyword">,</span><span class="syntaxdefault"> 1.002568</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">tolerance </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> 0.25</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m<br />grid_pt </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> pt</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">to_a</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">map </span><span class="syntaxkeyword">{</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">|</span><span class="syntaxdefault">n</span><span class="syntaxkeyword">|<br /></span><span class="syntaxdefault">  b </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">(</span><span class="syntaxdefault"> n </span><span class="syntaxkeyword">/</span><span class="syntaxdefault"> tolerance </span><span class="syntaxkeyword">).</span><span class="syntaxdefault">to_i </span><span class="syntaxkeyword">*</span><span class="syntaxdefault"> tolerance<br />  r </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> n </span><span class="syntaxkeyword">%</span><span class="syntaxdefault"> tolerance<br />  </span><span class="syntaxkeyword">(</span><span class="syntaxdefault">r </span><span class="syntaxkeyword">></span><span class="syntaxdefault"> tolerance </span><span class="syntaxkeyword">/</span><span class="syntaxdefault"> 2</span><span class="syntaxkeyword">)</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">?</span><span class="syntaxdefault"> b </span><span class="syntaxkeyword">+</span><span class="syntaxdefault"> tolerance </span><span class="syntaxkeyword">;</span><span class="syntaxdefault"> b<br /></span><span class="syntaxkeyword">}<br /></span><span class="syntaxdefault">grid_pt </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> Geom</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Point3d</span><span class="syntaxkeyword">.new(</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">*</span><span class="syntaxdefault">grid_pt </span><span class="syntaxkeyword">)<br /><br /></span><span class="syntaxdefault">puts </span><span class="syntaxstring">"Original; #{pt}"<br /></span><span class="syntaxdefault">puts </span><span class="syntaxstring">"Tolerance; #{tolerance}"<br /></span><span class="syntaxdefault">puts </span><span class="syntaxstring">"Grid Point; #{grid_pt}"&nbsp;</span><span class="syntaxdefault"></span>

Output:
Original: (3976,879mm, 3760,209mm, 1002,568mm) Tolerance: 250mm Grid Point: (4000mm, 3750mm, 1000mm)

thomthom · 26 Mar 2012, 12:35

Test module - adjust the vertices in the active context to grid.

<span class="syntaxdefault">module&nbsp;GridSnap<br /><br />&nbsp;&nbsp;def&nbsp;self</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">round_point</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">point</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">grid_pt&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">point</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">to_a</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">map&nbsp;</span><span class="syntaxkeyword">{&nbsp;|</span><span class="syntaxdefault">n</span><span class="syntaxkeyword">|<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">b&nbsp;</span><span class="syntaxkeyword">=&nbsp;(&nbsp;</span><span class="syntaxdefault">n&nbsp;</span><span class="syntaxkeyword">/&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">).</span><span class="syntaxdefault">to_i&nbsp;</span><span class="syntaxkeyword">*&nbsp;</span><span class="syntaxdefault">tolerance<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;r&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">n&nbsp;</span><span class="syntaxkeyword">%&nbsp;</span><span class="syntaxdefault">tolerance<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">r&nbsp;</span><span class="syntaxkeyword">>&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">/&nbsp;</span><span class="syntaxdefault">2</span><span class="syntaxkeyword">)&nbsp;?&nbsp;</span><span class="syntaxdefault">b&nbsp;</span><span class="syntaxkeyword">+&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">;&nbsp;</span><span class="syntaxdefault">b<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxkeyword">}<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">Geom</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Point3d</span><span class="syntaxkeyword">.new(&nbsp;*</span><span class="syntaxdefault">grid_pt&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;</span><span class="syntaxdefault">end<br />&nbsp;&nbsp;<br />&nbsp;&nbsp;def&nbsp;self</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">test_it<br />&nbsp;&nbsp;&nbsp;&nbsp;pt&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">Geom</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Point3d</span><span class="syntaxkeyword">.new(&nbsp;</span><span class="syntaxdefault">3.976879</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">3.760209</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">1.002568</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">0.25</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m<br />&nbsp;&nbsp;&nbsp;&nbsp;grid_pt&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">self</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">round_point</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">pt</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">puts&nbsp;</span><span class="syntaxstring">"Original;&nbsp;#{pt}"<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">puts&nbsp;</span><span class="syntaxstring">"Tolerance;&nbsp;#{tolerance}"<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">puts&nbsp;</span><span class="syntaxstring">"Grid&nbsp;Point;&nbsp;#{grid_pt}"<br />&nbsp;&nbsp;</span><span class="syntaxdefault">end<br />&nbsp;&nbsp;<br />&nbsp;&nbsp;def&nbsp;self</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">adjust_vertices</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">0.25</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">m&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">model&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_model<br />&nbsp;&nbsp;&nbsp;&nbsp;vertices&nbsp;</span><span class="syntaxkeyword">=&nbsp;[]<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxcomment">#&nbsp;Collect&nbsp;vertices.<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxkeyword">for&nbsp;</span><span class="syntaxdefault">e&nbsp;in&nbsp;model</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_entities<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;vertices&nbsp;</span><span class="syntaxkeyword"><<&nbsp;</span><span class="syntaxdefault">e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">vertices&nbsp;</span><span class="syntaxkeyword">if&nbsp;</span><span class="syntaxdefault">e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(&nbsp;</span><span class="syntaxdefault">Sketchup</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Edge&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">end<br />&nbsp;&nbsp;&nbsp;&nbsp;vertices</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">flatten</span><span class="syntaxkeyword">!<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">vertices</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">uniq</span><span class="syntaxkeyword">!<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxcomment">#&nbsp;Calculate&nbsp;grid&nbsp;adjustments.<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">vectors&nbsp;</span><span class="syntaxkeyword">=&nbsp;[]<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">entities&nbsp;</span><span class="syntaxkeyword">=&nbsp;[]<br />&nbsp;&nbsp;&nbsp;&nbsp;for&nbsp;</span><span class="syntaxdefault">vertex&nbsp;in&nbsp;vertices<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;pt&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">vertex</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">position<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;grid_pt&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">self</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">round_point</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">pt</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">tolerance&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">vector&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">pt</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">vector_to</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">grid_pt&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">next&nbsp;unless&nbsp;vector</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">valid</span><span class="syntaxkeyword">?<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">entities&nbsp;</span><span class="syntaxkeyword"><<&nbsp;</span><span class="syntaxdefault">vertex<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;vectors&nbsp;</span><span class="syntaxkeyword"><<&nbsp;</span><span class="syntaxdefault">vector<br />&nbsp;&nbsp;&nbsp;&nbsp;end<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxcomment">#&nbsp;Apply&nbsp;transformations<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">model</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_entities</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">transform_by_vectors</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">entities</span><span class="syntaxkeyword">,&nbsp;</span><span class="syntaxdefault">vectors&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">puts&nbsp;</span><span class="syntaxstring">"#{entities.size}&nbsp;adjusted&nbsp;to&nbsp;grid."<br />&nbsp;&nbsp;</span><span class="syntaxdefault">end<br /><br />end<br /></span>

Dan Rathbun · 26 Mar 2012, 12:54

How about that ??

... from concept to module in under a hour.

TIG · 26 Mar 2012, 13:02

Could this then be a tiny step towards a poly-reducer?
As the vertices are 'rationalized' onto a 'grid' some faces could become coplanar and therefore the superfluous shared edges could be removed.
The fineness/coarseness of this 'grid' removes less/more 'detailing'...

thomthom · 26 Mar 2012, 13:09

Cubificator?

I was thinking it might be usable to repair troublesome model imported from CAD drawings. Occasionally I run into models where splitting a face with an edge results in duplicate faces. I suspect its due to some precision errors. Maybe if the vertices where adjusted to fit to a finely grained 3D grid the troubles would go away... ?

rossthompson · 26 Mar 2012, 14:13

ThomThom thanks so much for your support! I have had a go at running your test module. My understanding is that it should shift the points in the active selection to a 0.25m grid as specified in the code.

However I am having problems running the module. I have attempted to add it to the tools menu as below, but I am not 100% sure how to 'call' the routine. Appologies if I'm being an idiot - I am new to ruby scripting!


    module GridSnap

      def self.round_point( point, tolerance )
        grid_pt = point.to_a.map { |n|
          b = ( n / tolerance ).to_i * tolerance
          r = n % tolerance
          (r > tolerance / 2) ? b + tolerance ; b
        }
        Geom;;Point3d.new( *grid_pt )
      end
      
      def self.test_it
        pt = Geom;;Point3d.new( 3.976879.m, 3.760209.m, 1.002568.m )
        tolerance = 0.25.m
        grid_pt = self.round_point( pt, tolerance )
        
        puts "Original; #{pt}"
        puts "Tolerance; #{tolerance}"
        puts "Grid Point; #{grid_pt}"
      end
      
      def self.adjust_vertices( tolerance = 0.25.m )
        model = Sketchup.active_model
        vertices = []
        # Collect vertices.
        for e in model.active_entities
          vertices << e.vertices if e.is_a?( Sketchup;;Edge )
        end
        vertices.flatten!
        vertices.uniq!
        # Calculate grid adjustments.
        vectors = []
        entities = []
        for vertex in vertices
          pt = vertex.position
          grid_pt = self.round_point( pt, tolerance )
          vector = pt.vector_to( grid_pt )
          next unless vector.valid?
          entities << vertex
          vectors << vector
        end
        # Apply transformations
        model.active_entities.transform_by_vectors( entities, vectors )
        puts "#{entities.size} adjusted to grid."
      end

    end

# Menu Entry;

UI.menu("Tools").add_item("GridSnap") { GridSnap } if not file_loaded?("GridSnap.rb") 
file_loaded("GridSnap.rb")

I think this could be a very useful tool for cleaning many types of imported geometry.

Ross

Dan Rathbun · 26 Mar 2012, 14:21

@thomthom said:

Cubificator?

Polyhedronizer ?

Orthogonizer ?

Orthographizer ?

OrthograFixer ?

TIG · 26 Mar 2012, 14:24

In case TT is away...
Inside the code making the menu use
{GridSnap**.adjust_vertices(1.cm)**}
It affects the whole model.
This example uses 1cm grid
Use another 'tolerance' if desired...
If you use () it defaults to 0.25m anyway...
It's only some example code and could be better assembled into something working on a selection with warnings and an 'undo' ???

TIG · 26 Mar 2012, 14:43

Not sure this reduced poly rock is so good ?'Cuboidalizer' is another name idea too... that or 'Discombobulizer'

Dan Rathbun · 26 Mar 2012, 14:49

Here's a beta version with an inputbox and undo operation...

It seemed to only change a cubes vertices in the Z axis ??

module GridSnap

  @@last_tolerance = 0.25.m

  class << self # PROXY CLASS

    def round_point( point, tolerance )
      grid_pt = point.to_a.map { |n|
        b = ( n / tolerance ).to_i * tolerance
        r = n % tolerance
        (r > tolerance / 2) ? b + tolerance ; b
      }
      Geom;;Point3d.new( *grid_pt )
    end
   
    def test_it
      pt = Geom;;Point3d.new( 3.976879.m, 3.760209.m, 1.002568.m )
      tolerance = @@last_tolerance
      grid_pt = round_point( pt, tolerance )
     
      puts "Original; #{pt}"
      puts "Tolerance; #{tolerance}"
      puts "Grid Point; #{grid_pt}"
    end
   
    def adjust_vertices( tolerance = @@last_tolerance )
      model = Sketchup.active_model
      vertices = []
      # Collect vertices.
      for e in model.active_entities
        vertices << e.vertices if e.is_a?( Sketchup;;Edge )
      end
      vertices.flatten!
      vertices.uniq!
      # Calculate grid adjustments.
      vectors = []
      entities = []
      for vertex in vertices
        pt = vertex.position
        grid_pt = round_point( pt, tolerance )
        vector = pt.vector_to( grid_pt )
        next unless vector.valid?
        entities << vertex
        vectors << vector
      end
      # Apply transformations
      model.active_entities.transform_by_vectors( entities, vectors )
      puts "#{entities.size} adjusted to grid."
    end
    
    def menu_command()
      title   = 'Adjust Vertices'
      prompt  = 'Tolerance'
      default = @@last_tolerance
      
      result = UI.inputbox([prompt],[@@last_tolerance],title) rescue @@last_tolerance
      if result
        begin
          ###
          Sketchup.active_model.start_operation("#{title} (#{Sketchup.format_length(result[0])})")
          #
          adjust_vertices( result[0] )
          #
          ###
          Sketchup.active_model.commit_operation()
        rescue
          Sketchup.active_model.abort_operation()
        else
          @@last_tolerance = result[0]
        end
      end
    end

  end # PROXY CLASS
  
  #{# RUN ONCE
  #
  unless file_loaded?("GridSnap.rb")
   
    # Menu Entry;
    UI.menu("Tools").add_item("GridSnap") { menu_command() }
    
    file_loaded("GridSnap.rb")
  
  end #}

end # module

thomthom · 26 Mar 2012, 18:53

@dan rathbun said:

It seemed to only change a cubes vertices in the Z axis ??

Should apply to X,Y and Z... Seemed to work correctly in my quick test...

daiku · 27 Mar 2012, 13:47

@dan rathbun said:

@thomthom said:

Cubificator?

Polyhedronizer ?

Orthogonizer ?

Orthographizer ?

OrthograFixer ?

It's like Autotune for cad! They can make you sound good, even if you can't sing.
If you are editing digital music, and you need to make the drum beats perfect, you can move the beats to the nearest sixteenth note, or whatever. It's call "quantizing".

Dan Rathbun · 27 Mar 2012, 15:00

@daiku said:

It's called "quantizing".

TRUE !!

Restriction to discrete values (or multiples thereof,) rather than any values in the set of possibles (real numbers, in this case.)

So.. the long term:
Vertex Positional Quantization

The short form:
Vertex to Grid

rossthompson · 28 Mar 2012, 13:30

Hi guys, I have had a play with Dan's Beta version and for me it works really well. The verticies are adjusted in X,Y and Z directions and the undo function works fine!

The only slight problem: it adjusts all the geometry in the model, rather than just the active selection. The original module just adjusted the active selection.

Any ideas?

Again thanks for the support - this script should be a realy time saver!

Ross

Dan Rathbun · 28 Mar 2012, 14:27

Well .. I did not think I changed the context of what Thomas' code did... just tried to wrap the code properly and added the menu_command() method to handle an inputbox.

I'll have a look at it.. again.

(And it's not really MY edition just because I added the inputbox.. it's still Thomas' thing.)