Is an entity in a surface

Al Hart

There is a model.Selection function is_surface(), which is true if the current selection is a surface.

I am looking for a similar function to determine if a single entity - say a face - is part of a surface.
(and/or to get an array of all entities which are in the same surface)

Any ideas?

thomthom

@al hart said:

I am looking for a similar function to determine if a single entity - say a face - is part of a surface.

<span class="syntaxdefault">def is_part_of_surface</span><span class="syntaxkeyword">?(</span><span class="syntaxdefault"> entity </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">  if entity</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">Edge </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">    entity</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">soft</span><span class="syntaxkeyword">?<br /></span><span class="syntaxdefault">  elsif entity</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">)<br /></span><span class="syntaxdefault">    entity</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">edges</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">any</span><span class="syntaxkeyword">?</span><span class="syntaxdefault"> </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">soft</span><span class="syntaxkeyword">?</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">}<br /></span><span class="syntaxdefault">  else<br />    false<br />  end<br />end<br /></span>

@al hart said:

(and/or to get an array of all entities which are in the same surface)

I'm actually about to write such a method for my own plugin. Don't have it yet, but it's just traversing all connected faces of soft edges.

(Note that it's only the soft property that SU use in regard to what is a Surface, smooth is just used for shading.)

thomthom

<span class="syntaxdefault">def&nbsp;get_surface</span><span class="syntaxkeyword">(&nbsp;</span><span class="syntaxdefault">face&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;</span><span class="syntaxdefault">surface&nbsp;</span><span class="syntaxkeyword">=&nbsp;{}&nbsp;</span><span class="syntaxcomment">#&nbsp;Use&nbsp;hash&nbsp;for&nbsp;speedy&nbsp;lookup<br />&nbsp;&nbsp;</span><span class="syntaxdefault">stack&nbsp;</span><span class="syntaxkeyword">=&nbsp;[&nbsp;</span><span class="syntaxdefault">face&nbsp;</span><span class="syntaxkeyword">]<br />&nbsp;&nbsp;</span><span class="syntaxdefault">until&nbsp;stack</span><span class="syntaxkeyword">.empty?<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">face&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">stack</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">shift<br />&nbsp;&nbsp;&nbsp;&nbsp;edges&nbsp;</span><span class="syntaxkeyword">=&nbsp;</span><span class="syntaxdefault">face</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">edges</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">select&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">soft</span><span class="syntaxkeyword">?&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;for&nbsp;</span><span class="syntaxdefault">edge&nbsp;in&nbsp;edges<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxkeyword">for&nbsp;</span><span class="syntaxdefault">face&nbsp;in&nbsp;edge</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">faces<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;next&nbsp;</span><span class="syntaxkeyword">if&nbsp;</span><span class="syntaxdefault">surface</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">key</span><span class="syntaxkeyword">?(&nbsp;</span><span class="syntaxdefault">face&nbsp;</span><span class="syntaxkeyword">)<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="syntaxdefault">stack&nbsp;</span><span class="syntaxkeyword"><<&nbsp;</span><span class="syntaxdefault">face<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;surface</span><span class="syntaxkeyword">[&nbsp;</span><span class="syntaxdefault">face&nbsp;</span><span class="syntaxkeyword">]&nbsp;=&nbsp;</span><span class="syntaxdefault">face<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;end<br />&nbsp;&nbsp;&nbsp;&nbsp;end<br />&nbsp;&nbsp;end<br />&nbsp;&nbsp;surface</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">keys<br />end<br /></span>

Al Hart

Thanks ThomThom,

I'll give these a try.

artmusicstudio

hi,
this seems to be an interesting approach, but
what is returned by the method?

is it an array of elements, i can iterate?
i am not yet familiar with "keys" etc..... -:)

if this gives back all entities of the "surface", how could i iterate thru it?
when i try, i get errors,
thanx
stan

@thomthom said:

<span class="syntaxdefault">def get_surface</span><span class="syntaxkeyword">(</span><span class="syntaxdefault"> face </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">  surface </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">{}</span><span class="syntaxdefault"> </span><span class="syntaxcomment"># Use hash for speedy lookup<br /></span><span class="syntaxdefault">  stack </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">[</span><span class="syntaxdefault"> face </span><span class="syntaxkeyword">]<br /></span><span class="syntaxdefault">  until stack</span><span class="syntaxkeyword">.empty?<br /></span><span class="syntaxdefault">    face </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> stack</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">shift<br />    edges </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> face</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">edges</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">select </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">soft</span><span class="syntaxkeyword">?</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">}<br /></span><span class="syntaxdefault">    for edge in edges<br />      for face in edge</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">faces<br />        next if surface</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">key</span><span class="syntaxkeyword">?(</span><span class="syntaxdefault"> face </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">        stack </span><span class="syntaxkeyword"><<</span><span class="syntaxdefault"> face<br />        surface</span><span class="syntaxkeyword">[</span><span class="syntaxdefault"> face </span><span class="syntaxkeyword">]</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> face<br />      end<br />    end<br />  end<br />  surface</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">keys<br />end<br /></span>

slbaumgartner

The return is an Array of all the Faces from any surface containing the Face passed as the argument. If the Face is not in a surface, the return will be an empty array.

artmusicstudio

@slbaumgartner said:

The return is an Array of all the Faces from any surface containing the Face passed as the argument. If the Face is not in a surface, the return will be an empty array.

hello,
thanx a lot. yes,

in the mean time i renamed the array to @surface.keys and got the array back. works perfectly.

i have to find out, if there is a way to return this array without renaming (return xxxx ???)

stan

thomthom

Where did you get @surface from?

Dan Rathbun

@artmusicstudio said:

i am not yet familiar with " keys" etc..... -:)

Go to the Ruby Resources "Sticky Thread" here:
RUBY PROGRAMMING REFERENCES

Get the CHM files for whatever version Ruby your SketchUp is using.
SketchUp v8, 2013 and earlier uses Ruby 1.8.6
(some earlier version used Ruby 1.8.5 and 1.8.0, FYI)

THEN ... lookup the Hash#keys() method

artmusicstudio

@thomthom said:

Where did you get @surface from?

hi thomthom,

the method is

having a smooth mesh with any loops projected on it and intesect

selection of one or more surfaces by user and calling the method

iterating thru selected surfaces

iteration thru all elements within one of them

further operation with edges within the surface, especially the smooth ones

this peace of code for surface works super for me.

stan

artmusicstudio

@dan rathbun said:

@artmusicstudio said:

i am not yet familiar with " keys" etc..... -:)

Go to the Ruby Resources "Sticky Thread" here:
RUBY PROGRAMMING REFERENCES

Get the CHM files for whatever version Ruby your SketchUp is using.
SketchUp v8, 2013 and earlier uses Ruby 1.8.6
(some earlier version used Ruby 1.8.5 and 1.8.0, FYI)

THEN ... lookup the Hash#keys() method

hi dan, thanx,
next one to be studied (of still so many....). -:)

just to be sure of universality (ruby-versions), i run the code always in 2014 and v8 in win7, vista and xp....
stan

slbaumgartner

TT's snippet earlier in this post contains a couple of bugs: it will raise an exception if the
argument isn't a Face (or something that supports #edges), and it will find false surfaces
built where more than two Faces meet at a soft Edge. The below fixes these issues.


def get_surface( face )
  return [] unless face.is_a?(Sketchup;;Face)
  surface = {} # Use hash for speedy lookup
  stack = [ face ]
  until stack.empty?
    face = stack.shift
    edges = face.edges.select { |e| e.soft? && e.faces.length == 2}
    for edge in edges
      for face in edge.faces
        next if surface.key?( face )
        stack << face
        surface[ face ] = face
      end
    end
  end
  surface.keys
end

tt_su

That's for that revised version!