Transforming an array of points

jolran

Ah you mean put result in Hash ?

start = Time.now
newHash = {}
10000.times {
for i in 0...polygonials.length
  newHash[i] = polygonials[i].collect{|p| p.transform(tr) }
end
}
puts "HASH Transforms And Collect; #{Time.now - start}"

=>2.381

Garry K

You could render the mesh after the timers to maintain benchmark validity.

Have you tried traversing your polygons?
mesh.polygon_points_at( index )
Shouldn't this give you the same results as an outer_loop on a face?
The question I would have is although you can get the points for each polygon - Is there a way to tie in a reference to the faces in the model once you have rendered the mesh?
I would hope that the entities in the group immediately after a fill_from_mesh would be in mesh polygon index order. So there should be a 1 to 1 relationship.

I haven't played with hashes yet - so my question is probably confusing to you. Although I've programmed for many years and also played with CAD for many years I've only logged 3 or so months with Sketchup since I got serious about it (guess I caught the Sketchup virus).

jolran

@unknownuser said:

You could render the mesh after the timers to maintain benchmark validity.

Yeah, for those tests that edit in Place. Otherwise it would be too intense for Sketchup.

@unknownuser said:

The question I would have is although you can get the points for each polygon - Is there a way to tie in a reference to the faces in the model once you have rendered the mesh?

I'm just moving Points in this code. I reckon you'd have to recollect faces afterwards
and do some boolean tests. There's normal_at which could be used for ex.
It all depends on (referring to your other question) if face order == polygon index order. I should test that as well unless someone else already knows..

I'm pretty new to programming, so there can be lots of holes in the logic of my tests.
But what better way to learn than trying to solve a problem, right?

Hashes in Ruby are supposed to have much faster lookup than arrays. I think that's what Thomthom tried to point out earlier.

tt_su

@garry k said:

I think that we gain performance in the actual transform but may loose it accessing the points in the mesh.

Geom::PolygonMesh.points? http://www.sketchup.com/intl/en/developer/docs/ourdoc/polygonmesh.php#points

Garry K

Sorry - bad terminology. I was talking read and write access.
the only write access we have is mesh.add_point.
I'm still thinking as a C / C++ programmer.

tt_su

@garry k said:

Sorry - bad terminology. I was talking read and write access.
the only write access we have is mesh.add_point.

PolygonMesh.set_point
http://www.sketchup.com/intl/en/developer/docs/ourdoc/polygonmesh.php#set_point

jolran

Yet Another test

Don't know how reliable this test is but it appears face get appended in the same order as indexed in Polygonmesh. But Polygonmesh Count indexes starting at 1.

Edit: Updated for adding c_point in polygonmesh index as well. But wonder how hidden edges affect the Index ordering..

The API says:

@unknownuser said:

The negative values should not be used as an index for point_at, take the positive value of the index value in the polygon array

Perhaps hidden edges will only happend if mesh is constructed from a collection of Sketchup::Face's. Not relevant in this case.
In that case maybe use index.abs or perhaps double negation: index = index<0 ? -index : index

ents = Sketchup.active_model.active_entities

def centerpoints(f)
  cx = (f[0].x + f[1].x + f[2].x + f[3].x)/4
  cy = (f[0].y + f[1].y + f[2].y + f[3].y)/4
  cz = (f[0].z + f[1].z + f[2].z + f[3].z)/4
  return Geom;;Point3d.new(cx, cy, cz)
end


face1 = [ 
  Geom;;Point3d.new(-5,-5,0), Geom;;Point3d.new(5,-5,0),
  Geom;;Point3d.new(5,5,0), Geom;;Point3d.new(-5,5,0) 
]

#create points for 4 faces
faceHash = {}
for i in (0...4) 
   faceHash[i] = face1
   face1 = face1.collect{|pt| pt.offset([20,0,0])}
end

#get refference to the center of "face"#3 Before appending to mesh.

fC = centerpoints(faceHash[2])
ents.add_cpoint(fC)

# Bit strange to loop hash this way, but they get ordered.
msh = Geom;;PolygonMesh.new
for n in (0...faceHash.length)
  msh.add_polygon(faceHash[n])
end

#Test PolygonMesh index. How does hidden edges affect indexes for this ?
# +1 index for polygons in Mesh. 2 c_points should get added at same spot
meshface3 = msh.polygon_points_at(2+1)
mc = centerpoints(meshface3)
ents.add_cpoint(mc)


group = ents.add_group
group.entities.add_faces_from_mesh(msh)
faces = group.entities.grep(Sketchup;;Face)

#Red material to face 3
faces[2].material = "red"