Preventing add_curve curves exploding...

driven · 14 May 2016, 16:09

or repairing...

I posted this on the 'official' site but know quite a few only visit here...

Using entities.add_curve(points_array) will return a continuous selectable curve...

If you add this curve to a surface it remains a continuous selectable curve...

if you add a 'surface' to the curve it becomes a series of disconnected edges, but each edge still reports as being a curve...

this occurs for surfaces formed from the curve to a centre point or between two curves...

the gif shows a demo from the script attached...

I have tried many ways of grouping, moving, exploding in different sequences, but they all result exactly the same as this one...

I looked at many welding scripts, but they either fail to work, are buggy or spend a lot of effort 'looking' for an edge array...

As already have original point arrays, is there a way to remedy this splitting of the curses highlighted in the gif...

# script to aid in disscussion of welding surface edges...
model = Sketchup.active_model
sel   = model.selection
ents  =  model.active_entities
view  = model.active_view
mats  = model.materials

# cylindrical sine wave pair on a unit radius with 24 sides...
wave = [[1.0, 0.0, 0.0], [0.9659258262890683, 0.25881904510252074, 0.050799999999999984], [0.8660254037844387, 0.49999999999999994, 0.08798818102449896], [0.7071067811865476, 0.7071067811865475, 0.1016], [0.5000000000000001, 0.8660254037844386, 0.08798818102449898], [0.25881904510252096, 0.9659258262890682, 0.05080000000000003], [6.123233995736766e-17, 1.0, 1.2442411479337108e-17], [-0.25881904510252063, 0.9659258262890683, -0.05079999999999998], [-0.4999999999999998, 0.8660254037844388, -0.08798818102449893], [-0.7071067811865475, 0.7071067811865476, -0.1016], [-0.8660254037844385, 0.5000000000000003, -0.087988181024499], [-0.9659258262890682, 0.258819045102521, -0.050800000000000047], [-1.0, 1.2246467991473532e-16, -2.4884822958674216e-17], [-0.9659258262890684, -0.25881904510252035, 0.05079999999999989], [-0.8660254037844388, -0.4999999999999998, 0.08798818102449892], [-0.7071067811865479, -0.7071067811865471, 0.1016], [-0.5000000000000004, -0.8660254037844384, 0.08798818102449903], [-0.25881904510252146, -0.9659258262890681, 0.05080000000000014], [-1.8369701987210297e-16, -1.0, 3.267705224142925e-17], [0.2588190451025203, -0.9659258262890684, -0.050799999999999915], [0.4999999999999993, -0.866025403784439, -0.08798818102449889], [0.7071067811865475, -0.7071067811865477, -0.1016], [0.8660254037844384, -0.5000000000000004, -0.08798818102449901], [0.9659258262890681, -0.2588190451025215, -0.05080000000000014], [1.0, 0.0, -0.0]]
rev_wave = wave.reverse
#
outer_wave = []
rev_wave.each{|pt| outer_wave << [pt[0], pt[1], pt[2] + 0.1]}
#
inner_wave = []
outer_wave.each{|pt| inner_wave << [pt[0] * 0.5, pt[1] * 0.5, pt[2]]}

# single undo
model.start_operation('Wave', false, false, false)

# add colors to watch the order of construction...
mat_names = []
mats.each{|n| mat_names << n.name}
	mats.add('inner').color   = 'skyblue'    unless mat_names.include?('inner')
	mats.add('outer').color   = 'seashell' unless  mat_names.include?('outer')

# Make the empty 'wave' group.
wave_grp = ents.add_group()

# Make array to hold entities...
wave_ents = wave_grp.entities

# Add outer points to inner points for the radial pairs...
radial = outer_wave.zip(inner_wave)
radial_edges = radial.each {|pr|
  e = wave_ents.add_edges(pr)
  e[0].soft="true"
  e[0].smooth="true"
	# for watching only
  sel.add(e)
	view.refresh
}
sel.clear

# Add  outer points to offset inner points for the diagonal pairs...
diagonal = outer_wave.zip(inner_wave[0..-2].unshift(inner_wave[-1]))
diagonal_edges = diagonal.each {|pr|
  e = wave_ents.add_edges(pr)
  e[0].soft="true"
  e[0].smooth="true"
  e[0].casts_shadows = false
	# for watching only
  sel.add(e)
	view.refresh
}
sel.clear

# Add the inner 'curve' and face created between curve, radial and diagonal edges...
inner_edges = wave_ents.add_curve(inner_wave)
i = 0
inner_edges.each {|e|
	e.find_faces
	f = e.faces[0]
	i += 1
	# for watching only
	f.material = 'inner'
  sel.add(f)
	view.refresh
}
sel.clear
#
outer_edges = wave_ents.add_curve(outer_wave)
	i = 0
	outer_edges.each {|e|
	e.find_faces
	f = e.faces[0]
	i += 1
	# for watching only
	f.material = 'outer'
  sel.add(f)
	view.refresh
}
sel.clear

sel.add(inner_edges, outer_edges)

model.commit_operation

another gif...

If I run Curvisard or Reweld on the selected 'curves' after making them, they are repaired almost instantly...

However, they spend time looking for the 'edges' and I already have those...

I tried one version where I called Reweld::recurve_curve but it's quite buggy and adds geometry in a very odd fashion that can bugsplat...

I couldn't fathom how to link into Curvisard which is much more common and very reliable...

I would prefer to do it directly in the code, but can't find a way to achieve this...

john

TIG · 14 May 2016, 16:58

Here's the working example...
We have had separate PMs about this before...

The order of operations is critical.
Make the softened edges, make the facets, make a curve in a group and explode it over the facets.
If desired turn the smoothed edges back solid...

Try this code pasted into the Ruby Console, in an empty model, to make two 1" facets with a shared 'curve' edge-set which straddles an otherwise splitting cross-edge that is smoothed to stop the splitting...

out the smoothing code-line and/or the final un-smoothing code-line to see the differences.

    ### the vertices of two rectangles sharing edge b,e
    a=[0,0,0]
    b=[0,0,1]
    c=[1,0,1]
    d=[1,1,1]
    e=[0,1,1]
    f=[0,1,0]
    ###
    model=Sketchup.active_model
    aents=model.active_entities
    ###
    group=aents.add_group()
    gents=group.entities
    ### add softened edge - otherwise splitting at b.e
    edge=gents.add_line(b,e); edge.smooth=true; edge.soft=true
    ###
    gents.add_face(a,b,e,f)
    gents.add_face(b,c,d,e)
    ###
    subgp=aents.add_group()
    sents=subgp.entities
    sents.add_curve(a,b,c,d,e,f)
    ###
    group.explode
    subgp.explode
    ### reset edge b,e back solid, if desired
    edge.smooth=false; edge.soft=false
    ###

driven · 14 May 2016, 20:24

I'll post the code here, because it's where I searched for a solution first and couldn't find one...

I striped out the colouring but left the selection add, as a progress bar substitute...

# with Tig's advice from PM ...
model = Sketchup.active_model
sel   = model.selection
ents  =  model.active_entities
view  = model.active_view
mats  = model.materials

# cylindrical sine wave pair on a unit radius with 24 sides...
wave = [[1.0, 0.0, 0.0], [0.9659258262890683, 0.25881904510252074, 0.050799999999999984], [0.8660254037844387, 0.49999999999999994, 0.08798818102449896], [0.7071067811865476, 0.7071067811865475, 0.1016], [0.5000000000000001, 0.8660254037844386, 0.08798818102449898], [0.25881904510252096, 0.9659258262890682, 0.05080000000000003], [6.123233995736766e-17, 1.0, 1.2442411479337108e-17], [-0.25881904510252063, 0.9659258262890683, -0.05079999999999998], [-0.4999999999999998, 0.8660254037844388, -0.08798818102449893], [-0.7071067811865475, 0.7071067811865476, -0.1016], [-0.8660254037844385, 0.5000000000000003, -0.087988181024499], [-0.9659258262890682, 0.258819045102521, -0.050800000000000047], [-1.0, 1.2246467991473532e-16, -2.4884822958674216e-17], [-0.9659258262890684, -0.25881904510252035, 0.05079999999999989], [-0.8660254037844388, -0.4999999999999998, 0.08798818102449892], [-0.7071067811865479, -0.7071067811865471, 0.1016], [-0.5000000000000004, -0.8660254037844384, 0.08798818102449903], [-0.25881904510252146, -0.9659258262890681, 0.05080000000000014], [-1.8369701987210297e-16, -1.0, 3.267705224142925e-17], [0.2588190451025203, -0.9659258262890684, -0.050799999999999915], [0.4999999999999993, -0.866025403784439, -0.08798818102449889], [0.7071067811865475, -0.7071067811865477, -0.1016], [0.8660254037844384, -0.5000000000000004, -0.08798818102449901], [0.9659258262890681, -0.2588190451025215, -0.05080000000000014], [1.0, 0.0, -0.0]]

# waves have an additional point to complete the circle...
segments = wave.length - 1

# single undo
model.start_operation('wave')

# Make the empty 'container' group.
container = ents.add_group()
cont_ents = container.entities

# add the empty surf_grp() to cont_ents
surf_grp  = cont_ents.add_group()
surf_ents = surf_grp.entities

# Add Surface soft edges and faces using offset points...
i = 0
segments.times do
  f = surf_ents.add_face(ORIGIN, wave[i], wave[i + 1])
  view.refresh
  f.edges.each{|e|
    e.soft="true"
    e.smooth="true"
    sel.add(e)
  }
  i += 1
  view.refresh
end

# add the wave to cont_ents...
cont_ents.add_curve(wave)

# and explode the surface faces...
surf_grp.explode
sel.clear
model.commit_operation

EDIT: after getting the other working using add_face I made a few adjustment to this code...

john