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[Plugin] triangulateFaces.rb v1.2 20101120

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  • T Offline
    TIG Moderator
    last edited by 26 Nov 2009, 16:20

    This was CJP's code...
    I've messed on with your ideas but can only get the front OR back UVs to work... how do I get both ? Here's the re-jigged code so far...

    def triangulateFace(face)
        mesh=face.mesh(3)
        verts=mesh.points
        ents=Sketchup.active_model.active_entities
        mat=face.material
        bac=face.back_material
        face.erase!
        grp=ents.add_group
        grp.entities.add_faces_from_mesh(mesh)
        grp.entities.each{|e|
            if e.class==Sketchup;;Edge
                e.smooth=false
                e.soft=false           
            elsif e.class==Sketchup;;Face
              uva=verts.index(e.vertices[0].position)
              uvb=verts.index(e.vertices[1].position)
              uvc=verts.index(e.vertices[2].position)
              if mat
                uvsF=mesh.uvs(true)
                e.position_material(mat, [verts[uva],uvsF[uva], verts[uvb],uvsF[uvb], verts[uvc],uvsF[uvc]], true)
              end#if
              if bac
                uvsB=mesh.uvs(false)
                e.position_material(bac,[verts[uva],uvsB[uva], verts[uvb],uvsB[uvb], verts[uvc],uvsB[uvc]], false)
              end#if
            end#if
        }
        grp.explode
    end#def
    

    TIG

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    • T Offline
      thomthom
      last edited by 26 Nov 2009, 17:30

      That bit of code seem to work.

      Thomas Thomassen β€” SketchUp Monkey & Coding addict
      List of my plugins and link to the CookieWare fund

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      • T Offline
        TIG Moderator
        last edited by 26 Nov 2009, 18:29

        @thomthom said:

        That bit of code seem to work.

        It does work for the back_material but it doesn't map the front material's uvs...
        Try running it on a face with a hole in it and and materials front and back - both adjusted at angles/shear etc with Texture tool... Both materials are put back onto the now triangulated faces but the front material will be at its default settings...

        I can't see how to do it πŸ˜•

        TIG

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        • T Offline
          thomthom
          last edited by 26 Nov 2009, 19:13

          Holes and sheared textures seems fine.

          But, when I distort them, so the texture doesn't fit to a parallelogram, then it fails.
          And that's excatly the conversation I've been having with Whaat a couple of days ago. That in order to sample textures which are distorted you need four points. Which leads to the question of PolygonMeshes: what do you do then, because if you just sample the UV from each point in the polygon you only get tree samples.

          I wonder if PolygonMesh.uv_at(u,v) can be used though. The manual is not clear on this method. The description and example don't add up.

          Thomas Thomassen β€” SketchUp Monkey & Coding addict
          List of my plugins and link to the CookieWare fund

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          • T Offline
            TIG Moderator
            last edited by 26 Nov 2009, 22:01

            See what you mean - I had a distorted front face that failed...
            if you have 4 ubs's how do we check ? πŸ˜•

            TIG

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            • T Offline
              TIG Moderator
              last edited by 26 Nov 2009, 22:46

              I have some thoughts... πŸ’­
              The original face's mesh has a number of points - 3 or more.
              A texture usually has 3 uvs 'points'.
              A distorted texture has 4 uvs 'points'.
              How do these uvs 'points' relate to the mesh points ? If you give them the equivalent 'index' then they'll work until index=3...
              A face made from the mesh always has 3 points, these relate to the mesh points in sets of 3 - but how do these tie back to the texture uvs 'points' ? The fourth one index=3 fails ???
              How do we make an array to place the material that has this fourth pair of a 3D point and a uvs 'point' ? It must reflect the 'extra point' somehow ??

              I shall sleep on it and see if the little-grey-cells come up with anything... ➑

              TIG

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              • T Offline
                thomthom
                last edited by 26 Nov 2009, 22:54

                For my UV plugins I have used the UVHelper to sample the points. What I did then was sample four points of the face's place - completely ignoring the face's vertices.

                Maybe, for each face that's turned into a PolygonMesh, sample four points of the front and back. Then once converted into PolygonMesh, apply the sampled UV points to each of the polygon faces. That should work. All the created polygon faces are still on the old face's plane.

                Thomas Thomassen β€” SketchUp Monkey & Coding addict
                List of my plugins and link to the CookieWare fund

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                • T Offline
                  TIG Moderator
                  last edited by 26 Nov 2009, 22:56

                  More ideas... let me sleep... zzzzzzzzzzzzz x πŸ’­

                  TIG

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                  • T Offline
                    TIG Moderator
                    last edited by 30 Nov 2009, 14:41

                    def triangulateFace(face)
                    ### if already a triangle leave alone...
                     if face.vertices[3]
                      mesh=face.mesh(3)
                      ents=face.parent.entities
                      mat=face.material
                      bac=face.back_material
                      ###
                      p0=face.vertices[0].position
                      p1=face.vertices[1].position
                      p2=face.vertices[2].position
                      p3=face.vertices[3].position
                      ### get uvs
                      tw=Sketchup.create_texture_writer
                      uv_helperF=face.get_UVHelper(true,false,tw)
                      uv_helperB=face.get_UVHelper(false,true,tw)
                      uf0=uv_helperF.get_front_UVQ(p0)
                      uf1=uv_helperF.get_front_UVQ(p1)
                      uf2=uv_helperF.get_front_UVQ(p2)
                      uf3=uv_helperF.get_front_UVQ(p3)
                      ub0=uv_helperB.get_back_UVQ(p0)
                      ub1=uv_helperB.get_back_UVQ(p1)
                      ub2=uv_helperB.get_back_UVQ(p2)
                      ub3=uv_helperB.get_back_UVQ(p3)
                      ###
                      grp=ents.add_group
                      grp.entities.add_faces_from_mesh(mesh)
                      grp.entities.each{|e|
                        if e.class==Sketchup;;Edge
                          e.smooth=false
                          e.soft=false     
                        elsif e.class==Sketchup;;Face
                          if mat
                            e.position_material(mat,[p0,uf0, p1,uf1, p2,uf2, p3,uf3], true)
                          end#if
                          if bac
                            e.position_material(bac,[p0,ub0, p1,ub1, p2,ub2, p3,ub3], false)
                          end#if
                        end#if
                      }
                      face.erase!
                      grp.explode
                     end#if
                    end#def
                    

                    Seems to me that this should work... but it doesn't - Thomthom, any ideas πŸ˜•

                    TIG

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                    • T Offline
                      thomthom
                      last edited by 3 Dec 2009, 22:12

                      
                      def triangulateFace(face)
                      ### if already a triangle leave alone...
                      if face.vertices[3]
                        mesh=face.mesh(3)
                        ents=face.parent.entities
                        mat=face.material
                        bac=face.back_material
                        ###
                      	# (TT)
                      	# Instead sampling vertices we sample points of the face's plane.
                      	# This is because we need four points, and some times a face only has tree vertices.
                      	# And we also get the wrong result if any of the first four vertices are co-linear.
                      	samples = []
                      	samples << face.vertices[0].position			 # 0,0 | Origin
                      	samples << samples[0].offset(face.normal.axes.x) # 1,0 | Offset Origin in X
                      	samples << samples[0].offset(face.normal.axes.y) # 0,1 | Offset Origin in Y
                      	samples << samples[1].offset(face.normal.axes.y) # 1,1 | Offset X in Y
                        ### get uvs
                        tw=Sketchup.create_texture_writer
                      	# (TT)
                      	uv_helper=face.get_UVHelper(true,true,tw) # (TT) Only need one UV Helper
                      	xyz = []
                      	uv_f = []
                      	uv_b = []
                      	samples.each { |position|
                      		# XYZ 3D coordinates
                      		xyz << position
                      		# UV 2D coordinates
                      		# Front
                      		uvq = uv_helper.get_front_UVQ(position)
                      		uv_f << flattenUVQ(uvq)
                      		# Back
                      		uvq = uv_helper.get_back_UVQ(position)
                      		uv_b << flattenUVQ(uvq)
                      	}
                        ###
                        grp=ents.add_group
                        grp.entities.fill_from_mesh(mesh, true, 0) # (TT) Adds the mesh without soft/smooth edges. (and faster)
                        grp.entities.each{|e|
                          next unless e.class==Sketchup;;Face
                            if mat
                      		# (TT)
                      		# Position texture.
                      		pts = []
                      		(0..3).each { |i|
                      			pts << xyz[i]
                      			pts << uv_f[i]
                      		}
                              e.position_material(mat,pts, true)
                            end#if
                            if bac
                      		# (TT)
                      		# Position texture.
                      		pts = []
                      		(0..3).each { |i|
                      			pts << xyz[i]
                      			pts << uv_b[i]
                      		}
                              e.position_material(bac,pts, false)
                            end#if
                        }
                        face.erase!
                        grp.explode
                      end#if
                      end#def
                      # (TT)
                      # Get UV coordinates from UVQ matrix.
                      def flattenUVQ(uvq)
                      	return Geom;;Point3d.new(uvq.x / uvq.z, uvq.y / uvq.z, 1.0)
                      end
                      
                      

                      Thomas Thomassen β€” SketchUp Monkey & Coding addict
                      List of my plugins and link to the CookieWare fund

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                      • T Offline
                        TIG Moderator
                        last edited by 3 Dec 2009, 22:28

                        Thanks to CPhillips's inciteful ideas I have now made a 'joint' script called 'triangulateFaces.rb' which is attached. It uses CPhillips's triangulateFace(face) code [with a slight TIG addition for back_materials] and the TIG Plugin triangulateFaces(face_array)...
                        Originally 2009 (c) CPhillips* then (c) TIG** THEN (c) ThomThom ***
                        Script: triangulateFaces.rb
                        Code Usage: triangulateFace(face)*
                        Result: it triangulates a face... all Texture UVs are kept.
                        Plugin Usage: triangulateFaces(faces_array)**
                        Result: it triangulates faces in a selection...
                        v1.0
                        First Release: Def Code 'mesh' idea by CPhillips*,
                        retained back_materials added by TIG [failed] ###,
                        Plugin parts by TIG**. 20090729
                        v1.1
                        Rewritten entirely by TIG... THEN completely corrected by Thomthom (TT)!***
                        It now retains all Texture mapping successfully. 20091203
                        v1.2
                        Triangulated faces with 4 sides glitch fixed using intersection.
                        Get the latest version from here http://sketchucation.com/pluginstore?pln=triangulateFaces

                        TIG

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                        • T Offline
                          TIG Moderator
                          last edited by 3 Dec 2009, 22:32

                          Here's v1.1 http://forums.sketchucation.com/viewtopic.php?p=175613#p175613
                          β˜€
                          Thanks to Thomtom's knowledge of uvs mapping etc it now successfully triangulates any face [even with holes like Swiss Cheese] and keeps the front AND back uv texture mapping as it was ! Thanks!

                          TIG

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                          • GaieusG Offline
                            Gaieus
                            last edited by 4 Dec 2009, 00:31

                            Hi TIG,

                            Would it be possible for the plugin to triangulate faces with a more "even" or "regular" triangles? After this topic, I thought maybe pre-triangulating the face on the ramp would spare some extra hand-work but it seems that the plugin triangulates the faces just exactly the same way native SU does when autofolding.


                            TriangulateFaces.jpg


                            TriangulateFaces.skp

                            Gai...

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                            • T Offline
                              TIG Moderator
                              last edited by 4 Dec 2009, 11:24

                              @gaieus said:

                              Hi TIG,
                              Would it be possible for the plugin to triangulate faces with a more "even" or "regular" triangles? After this topic, I thought maybe pre-triangulating the face on the ramp would spare some extra hand-work but it seems that the plugin triangulates the faces just exactly the same way native SU does when autofolding.

                              TriangulateFaces uses the built-in SUp mesh making methods, which presumably match the auto-fold ones, hence the similarity.
                              You might have noticed that my ExtendEdgesByRails script does produce a neat set of faces as that can't use the mesh methods directly but has to make up its own...
                              Using EEbyRails is a MUCH simpler way of making a curved ramp - I've attached an example...EEbyRailsSimpleRamp1.pngEEbyRailsSimpleRamp2.pngEEbyRailsSimpleRamp.skp

                              TIG

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                              • GaieusG Offline
                                Gaieus
                                last edited by 4 Dec 2009, 12:18

                                Thanks TIG for the examples - although my question was more a bit "academical" and theoretical - but at least I know why the two meshes are similar.

                                Certainly the other twoo tools are also great and would probably fit more to this particular need - that moving of the face was just so simple method - too bad autofold screws it up.

                                Gai...

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                                • T Offline
                                  thomthom
                                  last edited by 4 Dec 2009, 12:24

                                  @gaieus said:

                                  Certainly the other twoo tools are also great and would probably fit more to this particular need - that moving of the face was just so simple method - too bad autofold screws it up.

                                  This triangulation would be a separate plugin. It's just too specific. But I've been thinking of this myself. I often find I want such partitioning. It seems that it's usually long strip of a face where two of the sides runs parallel-ish to each other. So you want an edge to go between each opposite vertex. I've had it on my list of things to do - just not got around to it yet.

                                  Thomas Thomassen β€” SketchUp Monkey & Coding addict
                                  List of my plugins and link to the CookieWare fund

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                                  • A Offline
                                    alz
                                    last edited by 5 Jan 2010, 16:11

                                    Yeah, I agree -- having a more uniform triangulation method is preferred. It makes things a lot easier developing models if it's more uniformed and less "meet all at one point".

                                    With the current method, I have to spend time flip-flopping various divisions (and sometimes just recutting the face).

                                    πŸ˜„

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                                    • W Offline
                                      Woz2007
                                      last edited by 31 May 2010, 18:54

                                      @tig said:

                                      ###,
                                      Plugin parts by TIG**. 20090729
                                      v1.1
                                      Rewritten entirely by TIG... THEN completely corrected by Thomthom (TT)!***
                                      It now retains all Texture mapping successfully. 20091203

                                      [attachment=0:kz9i3jbr]<!-- ia0 -->triangulateFaces.rb<!-- ia0 -->[/attachment:kz9i3jbr]

                                      Im using this & seeing the UV mapping failing...is this the latest version?!

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                                      • T Offline
                                        thomthom
                                        last edited by 31 May 2010, 19:19

                                        Got a sample of where it fails?

                                        Thomas Thomassen β€” SketchUp Monkey & Coding addict
                                        List of my plugins and link to the CookieWare fund

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                                        • W Offline
                                          Woz2007
                                          last edited by 1 Jun 2010, 10:34

                                          @thomthom said:

                                          Got a sample of where it fails?

                                          If you look at the texture in the tringle before & after you will see that it is affected. When I export the model as a mesh the surface is indeed messed up.

                                          I hope the image is enough to work from?!
                                          Thnaks for looking into this. This script could save me a lot of hassle if working correctly πŸ˜„


                                          before & after shot

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