Today, I tried to elaborate that is FreeCAD capable of converting 3D drawing to 2D and at the end of the day I said that FreeCAD fully capable of converting 3D drawing to 2D drawing by using Drawing module.

The Drawing module allows you to put your 3D work on paper. That is, to put views of your models in a 2D window and to insert that window in a drawing, for example a sheet with a border, a title and your logo and finally print that sheet. The Drawing module is currently under construction and more or less a technology preview!

When I copy paste the code present on http://www.freecadweb.org/wiki/index.php?title=Drawing_Module it gave the below output.

The below is updated code:

# First of all you need the Part and the Drawing module
import FreeCAD, Part, Drawing

# Create a small sample part
Part.show(Part.makeBox(100,100,100).cut(Part.makeCylinder(80,100)).cut(Part.makeBox(90,40,100)).cut(Part.makeBox(20,85,100)))

# Direct projection. The G0 means hard edge, the G1 is tangent continuous.
Shape = App.ActiveDocument.Shape.Shape
[visibleG0,visibleG1,hiddenG0,hiddenG1] = Drawing.project(Shape)
print "visible edges:", len(visibleG0.Edges)
print "hidden edges:", len(hiddenG0.Edges)

# Everything was projected on the Z-plane:
print "Bnd Box shape: X=",Shape.BoundBox.XLength," Y=",Shape.BoundBox.YLength," Z=",Shape.BoundBox.ZLength
print "Bnd Box project: X=",visibleG0.BoundBox.XLength," Y=",visibleG0.BoundBox.YLength," Z=",visibleG0.BoundBox.ZLength

# Different projection vector
[visibleG0,visibleG1,hiddenG0,hiddenG1] = Drawing.project(Shape,App.Vector(1,1,1))

# Project to SVG
resultSVG = Drawing.projectToSVG(Shape,App.Vector(1,1,1))
print resultSVG

# Create the body
App.ActiveDocument.addObject("Part::Box","Box")
App.ActiveDocument.Box.Length=100.00
App.ActiveDocument.Box.Width=100.00
App.ActiveDocument.Box.Height=100.00
 
App.ActiveDocument.addObject("Part::Box","Box1")
App.ActiveDocument.Box1.Length=90.00
App.ActiveDocument.Box1.Width=40.00
App.ActiveDocument.Box1.Height=100.00
 
App.ActiveDocument.addObject("Part::Box","Box2")
App.ActiveDocument.Box2.Length=20.00
App.ActiveDocument.Box2.Width=85.00
App.ActiveDocument.Box2.Height=100.00
 
App.ActiveDocument.addObject("Part::Cylinder","Cylinder")
App.ActiveDocument.Cylinder.Radius=80.00
App.ActiveDocument.Cylinder.Height=100.00
App.ActiveDocument.Cylinder.Angle=360.00
# Fuse two boxes and the cylinder
App.ActiveDocument.addObject("Part::Fuse","Fusion")
App.ActiveDocument.Fusion.Base = App.ActiveDocument.Cylinder
App.ActiveDocument.Fusion.Tool = App.ActiveDocument.Box1
 
App.ActiveDocument.addObject("Part::Fuse","Fusion1")
App.ActiveDocument.Fusion1.Base = App.ActiveDocument.Box2
App.ActiveDocument.Fusion1.Tool = App.ActiveDocument.Fusion
# Cut the fused shapes from the first box
App.ActiveDocument.addObject("Part::Cut","Shape")
App.ActiveDocument.Shape.Base = App.ActiveDocument.Box 
App.ActiveDocument.Shape.Tool = App.ActiveDocument.Fusion1
# Hide all the intermediate shapes 
Gui.ActiveDocument.Box.Visibility=False
Gui.ActiveDocument.Box1.Visibility=False
Gui.ActiveDocument.Box2.Visibility=False
Gui.ActiveDocument.Cylinder.Visibility=False
Gui.ActiveDocument.Fusion.Visibility=False
Gui.ActiveDocument.Fusion1.Visibility=False

# Insert a Page object and assign a template
App.ActiveDocument.addObject('Drawing::FeaturePage','Page')
App.ActiveDocument.Page.Template = App.getResourceDir()+'Mod/Drawing/Templates/A3_Landscape.svg'

# Create a view on the "Shape" object, define the position and scale and assign it to a Page
App.ActiveDocument.addObject('Drawing::FeatureViewPart','View')
App.ActiveDocument.View.Source = App.ActiveDocument.Shape
App.ActiveDocument.View.Direction = (0.0,0.0,1.0)
App.ActiveDocument.View.X = 10.0
App.ActiveDocument.View.Y = 10.0
App.ActiveDocument.Page.addObject(App.ActiveDocument.View)


# Create a second view on the same object but this time the view will be rotated by 90 degrees.
App.ActiveDocument.addObject('Drawing::FeatureViewPart','ViewRot')
App.ActiveDocument.ViewRot.Source = App.ActiveDocument.Shape
App.ActiveDocument.ViewRot.Direction = (0.0,0.0,1.0)
App.ActiveDocument.ViewRot.X = 80.0
App.ActiveDocument.ViewRot.Y = 100.0
App.ActiveDocument.ViewRot.Scale = 1.0
App.ActiveDocument.ViewRot.Rotation = 90.0
App.ActiveDocument.Page.addObject(App.ActiveDocument.ViewRot)


# Create a third view on the same object but with an isometric view direction. The hidden lines are activated too.
App.ActiveDocument.addObject('Drawing::FeatureViewPart','ViewIso')
App.ActiveDocument.ViewIso.Source = App.ActiveDocument.Shape
App.ActiveDocument.ViewIso.Direction = (1.0,1.0,1.0)
App.ActiveDocument.ViewIso.X = 335.0
App.ActiveDocument.ViewIso.Y = 140.0
App.ActiveDocument.ViewIso.ShowHiddenLines = True
App.ActiveDocument.Page.addObject(App.ActiveDocument.ViewIso)


# Change something and update. The update process changes the view and the page.
App.ActiveDocument.View.X = 160.0
App.ActiveDocument.View.Y = 140.0
App.ActiveDocument.View.Scale = 1.0
App.ActiveDocument.recompute()

# Get the SVG fragment of a single view
ViewSVG = App.ActiveDocument.View.ViewResult
print ViewSVG

print "Resulting SVG document: ",App.ActiveDocument.Page.PageResult
file = open(App.ActiveDocument.Page.PageResult,"r")
print "Result page is ",len(file.readlines())," lines long"

del file

# Insert a view with your content
App.ActiveDocument.addObject('Drawing::FeatureView','ViewSelf')
App.ActiveDocument.ViewSelf.ViewResult = """
 
  
  """
App.ActiveDocument.Page.addObject(App.ActiveDocument.ViewSelf)
App.ActiveDocument.recompute()
 
del ViewSVG

By running the above code we have two outputs. First is 3D design of the object.

Second is the image which is converted by using Drawing module in FreeCAD.

However, I understand the code little bit and changed the code little bit because positions of object on the drawing was not very good and they overlap with eachother.

http://www.freecadweb.org/wiki/index.php?title=Drawing_Module

There are many templates of drawing sheet present in FreeCAD are
http://www.freecadweb.org/wiki/index.php?title=Drawing_templates