has anyone done this?

I want a script that takes the selected points on an object and makes a face from them. ( have i missed this new function of 3dc?)

i just wrote the script in 5 minutes to do it, but, as i knew would happen, the active points aren't in the right order toi make a proper curve (concave?) - i just loop through the active points and take them from the active object.

so i need an algorithm to sort an array of points so i can add them to the face in the right order.  i think i once saw it on the net, but now i cant even think what to look for.

ta 4 your ideas
george

What a great idea, Geo,
 I doubt if you missed it, Les_Patterson and I talked about an easier way of making the window on models. It was awhile back and no one mentioned a function. Sure like it, though.

       KB

The sample create triangle plugin does this with 3 points - an expansion of this to more points would be useful.

That so true  

shoulda made myself clear.  I didn't say "wouldnt this be a good idea?'  I said 'someone do this for me' :-)

anyway her is some code that seems to work.  lazy stream of conscious programming.  one hand typing so no comments snd shrt var nms.  hell to debug.  debug code still in if you want to uncomment.

try. let me know.  hand hurts freom one hand typing so now got no good hands.  just save as somethinf.cs in scripts dir.  then select some vaguely coplanar points and run script.
george
---next line must be first in script------------------
Language = VBScript

'*********************************************************************************
' Purpose: Creates a Face from selectedc points
'*********************************************************************************

'Option Explicit          'require variable declarations
   Dim fso,db  
   const Pi= 3.14159265358979     'a greek delicacy
   Dim PiOn2
   PiOn2=Pi/2
   Dim apc                   'ActivePointCount
   Dim info()
Sub Main (CanvasApp)

   Dim Scene            'The current active scene
   Dim SceneRootGroup   'The root Group of the scene
   Dim Group            'The Group for our object (face)
   Dim CopyGroup        'where the face comes from
   Dim Object           'The object we are creating (face)
   Dim CopyObject
   Dim Face             'The face we are creating    
 
   Dim ii               'for looping
   Dim GridOriginX      'The 3D Canvas Grid's Origin (x)
   Dim GridOriginY      'The 3D Canvas Grid's Origin (y)
   Dim GridOriginZ      'The 3D Canvas Grid's Origin (z)
   Dim GridSize         'The 3D Canvas Grid's Size
   Dim GridInterval     'The 3D Canvas Grid's Interval
   Dim Points           'The user's desired # of points
   Dim NumericPoints    'Points converted to a number
   Dim FirstPointX      'First point in face
   Dim FirstPointY      'First point in face
   Dim FirstPointZ      'First point in face
'    Dim AxisX            'Axis to rotate the start position around
'    Dim AxisY            'Axis to rotate the start position around
'    Dim AxisZ            'Axis to rotate the start position around
   Dim Point            'Point we are creating
   Dim gx        'Group position
   Dim gy        '
   Dim gz        '

   Dim BoxMinX          'The Object's Bounding Box
   Dim BoxMinY          'The Object's Bounding Box
   Dim BoxMinZ          'The Object's Bounding Box
   Dim BoxMaxX          'The Object's Bounding Box
   Dim BoxMaxY          'The Object's Bounding Box
   Dim BoxMaxZ          'The Object's Bounding Box
   Dim Material         'The Face's MaterialConst
 
 
 
'variables for file handling

'   Set fso = CreateObject("Scripting.FileSystemObject"  
'     Set db = fso.CreateTextFile("c:\Program Files\Amabilis\Scripts\db.txt",true)


       'get the scene
       Set Scene = CanvasApp.GetActiveScene
      'get the active object count
       apc = Scene.GetActivePointCount
'        msgbox  ("apc " & apc)

      If apc > 2 Then
       
       redim info(apc,3)        'x,y,z,angle
       'get the root Group
       Set SceneRootGroup = Scene.GetRootGroup
       'create a Group for the object (face)
       Set Group = Scene.CreateGroup
       'add it to the scene
       SceneRootGroup.AddChild Group
       'give the Group a name - note that we can't do this
       'until the Group is added to the scene
       Group.SetName "FaceFromPoints Group"
       'create an object
       Set Object = Scene.CreateObject()
       'add the face to the object
       Set Face = Object.CreateFace
       'add a dummy normal to the object (we need one to add the points)
       Object.AddNormal 0,0,-1

       Set CopyObject = Scene.GetActiveObject(0)
       Set CopyGroup = CopyObject.GetParentGroup
       CopyGroup.GetPosition nothing,gx,gy,gz  
       Group.SetPosition nothing,0,gx,gy,gz      

       mx=0  'means
       my=0
       mz=0
       sdx=0 'standard devs
       sdy=0
       sdz=0
       for ii=0 to apc-1      
          Point = Scene.GetActivePoint(ii)
          CopyObject.GetPoint Point, info(ii,0), info(ii,1), info(ii,2)
          mx=mx+info(ii,0)
          my=my+info(ii,1)
          mz=mz+info(ii,2)
       Next
       mx=mx/apc
       my=my/apc
       mz=mz/apc
'msgbox ("centre " & mx & " " & my & " " & mz)
       for ii=0 to apc-1      
         sdx=sdx+(info(ii,0)-mx)^2
         sdy=sdy+(info(ii,1)-my)^2
         sdz=sdz+(info(ii,2)-mz)^2          
       Next
       sdx=sdx/apc
       sdy=sdy/apc
       sdz=sdz/apc
'msgbox ("sds " & sdx & sdy & sdz)
       if ((sdx            Axis=0
       elseif ((sdy           Axis=1
       else
          Axis=2
       end if
'msgbox("axis " & axis)

'move to 000

   
       for ii=0 to apc-1
             info(ii,0)=info(ii,0)-mx
             info(ii,1)=info(ii,1)-my
             info(ii,2)=info(ii,2)-mz
       next
       for ii=0 to apc-1

          select case Axis
           Case 2     'min var in z
             if info(ii,0)=0 then
                 info(ii,3)=0
                else
                 info(ii,3)=atn(info(ii,1)/info(ii,0))
                 info(ii,3) = QuadrantFix( info(ii,3),info(ii,1),info(ii,0) )
              end if
           Case 1   'min var in y
                if info(ii,2)=0 then
                   info(ii,3)=0
                else
                   info(ii,3)=atn(info(ii,0)/info(ii,2))
                   info(ii,3) = QuadrantFix (info(ii,3),info(ii,0),info(ii,2))
                end if  
           Case 0    'min var in x
               if info(ii,2)=0 then

                 if info(ii,1)>0 then
                       info(ii,3)=Pion2
                    else info(ii,3)=Pi+Pion2
                 end if  
               else
                 info(ii,3)=atn(info(ii,1)/info(ii,2))
'                  db.writeline("opp " & info(ii,1) & " adj " & info(ii,2) & " ang " & info(ii,3))
                 info(ii,3)= QuadrantFix (info(ii,3),info(ii,1),info(ii,2))
'                  db.writeline("angle fixre " & info(ii,3))
               end if

           end select
        next
        sort info, apc
'db.writeline("sorted"
for i=0 to apc-1
'db.writeline(info(i,3))
next
       for ii=0 to apc-1
             info(ii,0)=info(ii,0)+mx
             info(ii,1)=info(ii,1)+my
             info(ii,2)=info(ii,2)+mz
       next
        for ii=0 to apc-1      
           Object.AddPoint info(ii,0),info(ii,1),info(ii,2)
           Face.AddPointAndNormal ii,0
            'add the points and the normal to the fac\\
        Next
       

        'Create an appropriate material for the face
        Set Material = Scene.CreateMaterial

        'make it a nice color
        Material.SetColor .894,.773,.788

        'set the default diffuse value
        Material.SetDiffuse 60

        'set the default ambient value
        Material.SetAmbient 20

        'apply the material to the face
        Face.SetMaterial Material

        'add the object to the created Group
        'this also triggers the update to the database
        Group.AddObject Object

       'set the object name - note that we can't do this until
       'the object is added to a Group
        Object.SetName "FaceFromPoints"

        'Now that we know the size of the object let's set the position of the Group
        'so the face is visible
       
       'get the 3D Canvs grid details
'        CanvasApp.GetGridDetails GridOriginX, GridOriginY, GridOriginZ, GridSize, GridInterval

       'get the object's dimensions
'        Object.GetBoundingBox BoxMinX, BoxMinY, BoxMinZ, BoxMaxX, BoxMaxY, BoxMaxZ

       'Center the Object's Group on the Scene and have the object sitting nicely
       'on the surface
'        Group.SetPosition SceneRootGroup, 0, GridOriginX + GridSize / 2, GridOriginY - BoxMinY, GridOriginZ + GridSize /2
   else
    msgbox "need at least three points"
   End If    
'db.close
End Sub


sub sort(a(),points)
'db.writeline("sorting" & points)
dim i
dim j
dim k
dim min
dim tempmin
dim temp()
redim temp(3)
'redim buff(ipc,3)
'for i=0 to points-1' apc-1
'  db.writeline("a" & a(i,3))
'next
tempmin=0
for i=0 to points-2
 min=i
 tempmin=a(i,3)
 for j=i+1 to points-1
   if a(j,3)      min=j  
     tempmin=a(j,3)
   end if
 next  
 for k=0 to 3
   temp(k)=a(i,k)
   a(i,k)=a(min,k)
   a(min,k)=temp(k)
 next
next
'db.writeline("sorted" & points)
'for i=0 to points-1' apc-1
'   db.writeline(ii & "," & a(i,0) & "," & a(i,1) & ","  & a(i,2) & ","&  a(i,3))
'next
end sub

function quadrantfix (ang, opp, adj)

if ((opp>0) and (adj<0)) then  
 ang=Pi+ ang
elseif((opp<0) and [adj<0)) then
 ang=ang+Pi
elseif ((opp<0) and [adj>0)) then  
  ang=ang+ 2 *  Pi
end if
quadrantfix = ang
end function
'---------------------------code ends--------------

forgot to say you may need to invert the object created to see it.

I knew what you meant    :P
and I never heard of a Greek pie.

Geo

At the risk of evoking your rath, sore hand and all, does this mean I need to adjust the script ?
Sorry, the only part that made sense to me was about the pie.
KB

line 84

hmmm.  ijust copiewd from the post and it worked for me.   the error means the variable isn't declared, whic should be ok as Option explicit is commented out at the top.

sometimes wrapped long lines from  a post muck things up too.

back in a minute.

Geo,
I re-copied the script and it works fine. If this makes sense, the very first  "  '   " was missing.
 Thanks and sorry.
KB

try this

http://users.skynet.be/gj/canvas/scripts/

bed time long ago now, so hope it works

George