[Code] Print the transformation matrix

dacastror

Hi, I'm trying to print a transformation matrix, I tried the following:

pointdd = Geom::Point3d.new 11,22,33 tdd = Geom::Transformation.new pointdd a = tdd.to_a text="-------------------------------------------------------\n" 4.times do |b| 4.times do |e| if ((e+1)%4==0) text << a[e*4+b].to_s+"\n" else text << a[e*4+b].to_s+" "+" "+" "+" "+" "+" "+" "+" "+" "+" " end end end text<<"------------------------------------------------------\n" UI.messagebox( text, MB_MULTILINE)

I wanted to hear suggestions of more elegant ways to do this. (I wrote several times +" " for failure to escrbir several spaces followed here)

thank you for your attention.

danielbowring

Here's one in your format, although you should probably use one of the ones above (More info here)


def inspect_transformation_adv(t, args={})
    format = "%.#{args[;places] || 3}f"
    ta = t.to_a.map() {|i|
        format%[i]
    }
    maxlength = ta.max() {|i, j| i.length <=> j.length }.length
    ta = ta.map() {|i|
        i.ljust(maxlength)
    }
    return (0...4).map() {|i|
        (0...4).map() {|j|
            ta[j*4+i]
        }.join(args[;separator] || ', ')
    }.join("\n")
end


>>> point = Geom;;Point3d.new 11,22,33
>>> tdd = Geom;;Transformation.new pointdd
>>> puts inspect_transformation_adv(tdd)
1.000 , 0.000 , 0.000 , 11.000
0.000 , 1.000 , 0.000 , 22.000
0.000 , 0.000 , 1.000 , 33.000
0.000 , 0.000 , 0.000 , 1.000 
>>> puts inspect_transformation_adv(t, {;separator => ' '})
1.000  0.000  0.000  11.000
0.000  1.000  0.000  22.000
0.000  0.000  1.000  33.000
0.000  0.000  0.000  1.000

danielbowring


def inspect_transformation(t)
    ta = t.to_a
    return (0...4).collect() {|i|
        ta[i*4, 4].join(', ')
    }.join("\n")
end


>>> point = Geom;;Point3d.new 11,22,33
>>> tdd = Geom;;Transformation.new pointdd
>>> puts inspect_transformation(tdd)
1.0, 0.0, 0.0, 0.0
0.0, 1.0, 0.0, 0.0
0.0, 0.0, 1.0, 0.0
11.0, 22.0, 33.0, 1.0

Edit: And if you like things to line up:


def inspect_transformation_adv(t, args={})
    format = "%.#{args[;places] || 3}f"
    ta = t.to_a.map() {|i|
        format%[i]
    }
    maxlength = ta.max() {|i, j| i.length <=> j.length }.length
    ta = ta.map() {|i|
        i.ljust(maxlength)
    }
    return (0...4).collect() {|i|
        ta[i*4, 4].join(args[;separator] || ', ')
    }.join("\n")
end


>>> point = Geom;;Point3d.new 11,22,33
>>> tdd = Geom;;Transformation.new pointdd
>>> puts inspect_transformation_adv(tdd)
1.000 , 0.000 , 0.000 , 0.000 
0.000 , 1.000 , 0.000 , 0.000 
0.000 , 0.000 , 1.000 , 0.000 
11.000, 22.000, 33.000, 1.000

Edit: although that's not the orientation you use

thomthom

Is it to visually inspect the matrix of entities, if so you can use this tool: http://forums.sketchucation.com/viewtopic.php?t=44859

Dan Rathbun

Here's my simple brute force method:

  def trans_matrix_text( gt )

    return "Not a trnasformation object!" unless gt.is_a?(Geom;;Transformation)
    
    a = gt.to_a
    
    w = 3  # width
    a.each{|n| s = n.to_s.size; w = s if s>w }
    l = (w*4)+3
    
    # create a line output format string;
    fmt = "  | %#{w}s %#{w}s %#{w}s %#{w}s |\n"
    
    text = "\n"
    
    text << (32.chr*2)<<151.chr<<151.chr<<(32.chr*l)<<151.chr<<151.chr<<"\n"
    text << fmt % [  a[0].to_s,  a[1].to_s,   a[2].to_s,  a[3].to_s ]
    text << fmt % [  a[4].to_s,  a[5].to_s,   a[6].to_s,  a[7].to_s ]
    text << fmt % [  a[8].to_s,  a[9].to_s,  a[10].to_s, a[11].to_s ]
    text << fmt % [ a[12].to_s, a[13].to_s,  a[14].to_s, a[15].to_s ]
    text << (32.chr*2)<<151.chr<<151.chr<<(32.chr*l)<<151.chr<<151.chr<<"\n"
    
    return text

  end # def

  pt = Geom;;Point3d.new( 11,22,33 )
  text = trans_matrix_text( Geom;;Transformation.new(pt) )
  
  UI.messagebox( text, MB_MULTILINE, "Tranformation Matrix" )

I have tweaked my system by copying Consolas font to the font used by dialogs, so I have monospaced text output. (It was easier than tweaking the resources in the executable after each update.)

dacastror

Thanks for responding, I have helped a lot.

me a question arises about the transformations. if I need to apply a transformation to an object but not in the principal coordinate axes, but the coordinate axes of a group (rotated) what should I use?

(sorry for my bad English)

thomthom

You mean, transform an object around its own axis and not world axis?

dacastror

@thomthom said:

You mean, transform an object around its own axis and not world axis?

yes, exactly

thomthom

Create a local transformation and apply with with .transform!( tramsformation ) instead of setting the .transformation matrix manually. Or am I missing something?

dacastror

@thomthom said:

Create a local transformation and apply with with .transform!( tramsformation ) instead of setting the .transformation matrix manually. Or am I missing something?

How to create a local transformation? I would like to see some sample piece of code to guide me

dacastror

I wonder if there is any way to know the orientation of a group with respect to the axis of the world

TIG

You have the model's axes from X_AXIS etc and ORIGIN.
Then you have group.transformation.axes or group.transformation.xaxis etc... and group.transformation.origin too...
So you can find the relative locations [which are points3ds] and angles between axes [which are vector3ds] - see the methods for those types...

thomthom

@dacastror said:

@thomthom said:

Create a local transformation and apply with with .transform!( tramsformation ) instead of setting the .transformation matrix manually. Or am I missing something?

How to create a local transformation? I would like to see some sample piece of code to guide me

<span class="syntaxdefault"><br />point </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> instance</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">transformation</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">origin<br />vector </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> instance</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">transformation</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">yaxis<br />rotation </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> Geom</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Transformation</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">rotation</span><span class="syntaxkeyword">(</span><span class="syntaxdefault"> point</span><span class="syntaxkeyword">,</span><span class="syntaxdefault"> vector</span><span class="syntaxkeyword">,</span><span class="syntaxdefault"> 30</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">degrees </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">instance</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">transform</span><span class="syntaxkeyword">!(</span><span class="syntaxdefault"> rotation </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault"> </span>

dacastror

thank you very much Thomas and Tig that prompt reply!

I will try to implement your suggestions right now