[plugin]Export arcs, circles and vertex to dxf ?

Iltis

Hello TIG,

Thank you very much , I will try to do a first sample.
If you have the time to answer :
1/ Could you look the adds in your code (below), to get the arc entities. Am I right?
2/ If circ=false, how to get the Sketchup points of the entity?

Renaud

    circles = []
		arcs = []
    Sketchup.active_model.selection.grep(Sketchup;;Edge).each{|e|
      c = e.curve ### it's nil if a non-curve edge
      if c && c.is_a?(Sketchup;;ArcCurve) ### might be a circle or an arc
        circ = true
				arc = false
        c.vertices.each{|v|
          ### vertex has at least edges, but are there at least 2 and are both in the curve
          es = 0
          v.edges.each{|ee| es += 1 if c.edges.include?(ee) }
          if es != 2 ### it's an arc
						arc = true
            break
          end
        }
      else ### it's not a curve, or if it is it's not a circle or an arc
        circ = false
        next
      end
      circles << c if circ && ! arc && ! circles.include?(c) ### only add it to list once
			arcs << c if circ && arc && ! arcs.include?(c) ### only add it to list once
    }

    circles.each{|c| ### get circle's properties here, e.g.
      p c.center
      p c.radius
      p c.normal
    }
    arcs.each{|c| ### get arcs's properties here, e.g.
      p c.center
      p c.radius
      p c.normal
			p c.start_angle
			p c.end_angle
    }

TIG

I think you have an error in collecting the circles and arcs.
if es != 2 ### it's an arc arc = true circ = false break end
later
circles << c if circ && ! circles.include?(c) ### only add it to list once arcs << c if arc && ! arcs.include?(c) ### only add it to list once

Iltis

OK, right.

Iltis

Hello TIG,

When arc=false and circle=false, I wanted to store the entity in an array, could y help me? So at the end, I will use the edges of these entities for writing the polylines.

TIG

You now have two arrays - for circles and arcs.
Process each collected 'curve' in turn.
e.g.

circles.each{|c|
  c.edges.each{|e| # the curve's edges
    # process each edge 'e'
  }
}

Do the same for the 'arcs' array...

As it stands, you have arrays of curves which define circles of edges.

Those 'collections' are pointing to their 'edges' - i.e. defining their 'segments', which can be used as you want later...

Iltis

I misspoke, sorry. I'm OK for the arc and circle. They will be writen in the DXF file as ARC entity and CIRCLE entity.
What I don't see is how to collect the edges of the vertices of other entities of the selection/loop to write polylines (it's better than just lines for selection in the CAD softwares), when it's not an arc or a circle, in the "else" section of the previous code :


  else ### it's not a curve, or if it is it's not a circle or an arc
    circ = false
    arc = false
    
    ...

    next
  end

To write as polylines the dxf entities which are not circle or arc, I will use the following functions(*). The function dxf_write_polyline must be modified, because it's based on the loops of the faces, and the loop will be broken - or ignored - by the arcs and circles.


tform=Geom;;Transformation.new()
layername=model.active_layer.name

def dxf_transform_vertex(vertex, tform)
   point = Geom;;Point3d.new(vertex.position.x, vertex.position.y, vertex.position.z)
   point.transform! tform
   point
end

def dxf_write_polyline(face, tform, layername)
 face.loops.each do |aloop|
  $dxf_file.puts("  0\nPOLYLINE\n 8\n"+layername+"\n 66\n     1")
  $dxf_file.puts("70\n    8\n 10\n0.0\n 20\n 0.0\n 30\n0.0")
  for j in 0..aloop.vertices.length do
    if (j==aloop.vertices.length)
      count = 0
    else
      count = j
    end
    point = dxf_transform_vertex(aloop.vertices[count],tform)
    $dxf_file.puts( "  0\nVERTEX\n  8\nMY3DLAYER")
    $dxf_file.puts("10\n"+(point.x.to_f * $unit_conv).to_s)
    $dxf_file.puts("20\n"+(point.y.to_f * $unit_conv).to_s)
    $dxf_file.puts("30\n"+(point.z.to_f * $unit_conv).to_s)
    $dxf_file.puts( " 70\n     32")
  end
  if (aloop.vertices.length > 0)
    $dxf_file.puts( "  0\nSEQEND")
  end
 end
end

Thank you very much.

(*)existing plugin from http://www.guitar-list.com, original authors: Nathan Bromham, Konrad Shroeder

Iltis

Hi,
In fact, there is the problem of the order of the vertices to make the polylines. I think I must follow the loops, like in the initial code of guitar-list, but I must test the ".curve" of each vertex and extract the arcs, circles, and the polylines with vertices in the order. A little tricky for me, I will take a paper and a pencil!

TIG

Look at my 'Weld' tool.
That takes selected edges, and then welds them into a curve.
It has to sort the edges out in order and also get the start/end points correctly ordered.

However, a non-arc curve has a list of ordered vertices method, so you can get their positions as points using:
points = curve.vertices.collect{|v| v.position }
then use
points.each_with_index{|p, i| model.active_entities.add_text(i.to_s, p) }
to label the points to demonstrate to yourself that they are indeed ordered...

Iltis

Thanks TIG, I will work on it.

Iltis

Hello TIG,
Like other people, I have the following problem : with the (Sketchup::ArcCurve) entities, the arcs are always rotated, with the .start_angle value equal to 0.0 (and not equal to the angle with the X axe, the API documentation is wrong on this point in my situation - working with the entities of the loops).
Do you have a clean (and 3D) workaround?
Best regards,
Renaud.

Iltis

I just saw that the .xaxis propery of the arcs are rotated => start_angle=0 is right, because the reference is wrong. OK, knowing that, I can see how to do this.