[Sidefx-houdini-list] Space filling circles

Andrew D Lyons tstexture at gmail.com
Thu Aug 6 17:28:14 EDT 2009


As an interesting side topic to this thread, you can get some pretty
nice voronoi break-up patterns from a similar network to that which I
posted above. Again it's based on voronoi patterns being the dual of
delaunay triangulation:

http://www.comp.lancs.ac.uk/~kristof/research/notes/voronoi/

I've put an example in a second post here:

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=78063#78063

It would be great if SESI, or someone could wrap some of these up in SOPs...

Cheers

2009/8/6 Andrew D Lyons <tstexture at gmail.com>:
> Yep - sorry about the line wrapping on that post. There is a more
> succinct version of the script uploaded to here:
>
> http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=78063#78063
>
> Cheers
>
>
> 2009/8/6 David Johnson <daveinengland at gmail.com>:
>> I had to edit the example to fix the line wraps that the email put in, but
>> after that it ran just fine. Maybe someone could put it on odforce or in the
>> SideFX forum.
>>
>> Dave
>>
>> On Thu, Aug 6, 2009 at 6:58 AM, Steve Tucker <Steve.Tucker at starz.com> wrote:
>>
>>> Interesting.  If I attempt to run this in a new file, it doesn't work.
>>>  Can't create the geo object.  If I cd /obj and then try running it, I get a
>>> fatal exception error.
>>>
>>>  - Steve
>>>
>>> Stephen Tucker, VFX Artist
>>> p: 416.682.5200 x 5363  | f: 416.682.5209
>>> Starz Media Canada Co. | 230 Richmond Street East | Toronto, ON M5A 1P4
>>> www.starzanimation.com
>>>
>>>
>>> -----Original Message-----
>>> From: sidefx-houdini-list-bounces at sidefx.com [mailto:
>>> sidefx-houdini-list-bounces at sidefx.com] On Behalf Of Andrew D Lyons
>>> Sent: Wednesday, August 05, 2009 7:07 PM
>>> To: sidefx-houdini-list at sidefx.com
>>> Subject: Re: [Sidefx-houdini-list] Space filling circles
>>>
>>> That's an interesting problem. Not exactly circular - but close:
>>>
>>> Drop this in a textport:
>>> #######################################################
>>>
>>> # Automatically generated script: Wednesday August 05, 16:06
>>> \set noalias = 1
>>> set saved_path = `execute("oppwf")`
>>> opcf /obj
>>>
>>> # Node circle_cells (Object/geo)
>>> opadd -n geo circle_cells
>>> oplocate -x 12.6117 -y 2.05949 circle_cells
>>> opspareds '    group {  name    "stdswitcher5"  label   "Transform"
>>> parm
>>> {           name        "keeppos"           baseparm        joinnext
>>>  export      none    }
>>>        parm {      name        "pre_xform"         baseparm        export
>>>    none    }       parm
>>> {           name        "xOrd"      baseparm        joinnext        export
>>>      none    }
>>>        parm {      name        "rOrd"      baseparm        export      none
>>>    }       parm {
>>>  name   "t"         baseparm        export      all     }       parm {
>>>  name        "r"
>>> baseparm            export      all     }       parm {      name        "s"
>>>         baseparm
>>> export  none    }       parm {      name        "p"         baseparm
>>>  export      none    }
>>>        parm {      name        "scale"             baseparm        export
>>>    none    }       parm {
>>>  name  "lookatpath"        baseparm        export      none    }       parm
>>> {
>>> name    "lookup"            baseparm        export      none    }
>>> parm {
>>> name    "pathobjpath"       baseparm        export      none    }
>>> parm {
>>> name    "roll"      baseparm        export      none    }       parm {
>>>  name        "pos"
>>>            baseparm        export      none    }       parm {      name
>>>    "uparmtype"
>>> baseparm            export      none    }       parm {      name
>>>  "pathorient"
>>> baseparm            export      none    }       parm {      name
>>>  "up"        baseparm
>>> export  none    }       parm {      name        "bank"      baseparm
>>>  export      none
>>>        }     }      group {    name    "stdswitcher5_1"        label
>>> "Material"      parm
>>> {           name        "shop_materialpath"         baseparm
>>>  joinnext
>>> export  none    }       parm {      name        "shop_materialopts"
>>> baseparm
>>>  export none    }     }      group {    name    "stdswitcher5_2"
>>>        label   "Render"        parm {      name        "tdisplay"
>>>  baseparm
>>> export  none    }       parm {      name        "display"
>>> baseparm
>>> export  none    }       parm {      name        "vm_phantom"        label
>>>     "Phantom"
>>>  type   toggle      default     { "0" }             range       { 0 1 }
>>>         export      none
>>>            parmtag     { "spare_category" "Render" }   }       parm {
>>> name    "vm_renderable"             label       "Renderable"        type
>>>      toggle
>>> default { "1" }             range       { 0 1 }             export
>>>  none        parmtag     {
>>> "spare_category" "Render" }     }       group {             name
>>>  "folder0"
>>> label   "Shading"           parm {              name    "categories"
>>>      label   "Categories"
>>>                type    string          default { "" }          help    "A
>>> list of tags which can be
>>> used to select the object"              range   { 0 1 }
>>> export  none            parmtag {
>>> "spare_category" "Shading" }        }       parm {              name
>>>  "reflectmask"
>>>                label   "Reflection Mask"               type    oplist
>>>    default { "*" }                 range   { 0
>>> 1 }             export  none            parmtag { "oprelative" "/obj" }
>>>             parmtag {
>>> "opfilter" "!!OBJ/GEOMETRY!!" }                 parmtag { "spare_category"
>>> "Shading"
>>> }               parmtag { "opexpand" "1" }          }       parm {
>>>      name    "lightmask"
>>>                label   "Light Mask"            type    oplist
>>>  default { "*" }                 range   { 0 1 }
>>>                export  none            parmtag { "oprelative" "/obj" }
>>>             parmtag { "opfilter"
>>> "!!OBJ/LIGHT!!" }               parmtag { "spare_category" "Shading" }
>>>      parmtag {
>>> "opexpand" "1" }            }       parm {              name
>>>  "vm_volumefilter"
>>>                label   "Volume Filter"                 type    string
>>>    default { "gaussian" }
>>>                menu    {                   "box"       "Box Filter"
>>>        "gaussian"  "Gaussian"
>>> "bartlett"      "Bartlett (triangle)"               "catrom"
>>>  "Catmull-Rom"
>>> "hanning"       "Hanning"                   "blackman"  "Blackman"
>>>          "sinc"      "Sinc
>>> (sharpening)"           }               range   { 0 1 }
>>> export  none            parmtag {
>>> "spare_category" "Shading" }        }       parm {
>>>                name    "vm_volumefilterwidth"          label   "Volume
>>> Filter Width"
>>>                type    float           default { "1.5" }
>>> range   { 0.001 5 }             export  none
>>>                parmtag { "spare_category" "Shading" }      }       parm {
>>>                name    "vm_matte"              label   "Matte shading"
>>>             type    toggle          default {
>>> "0" }           range   { 0 1 }                 export  none
>>>  parmtag { "spare_category"
>>> "Shading" }         }   }       group {             name        "folder0_1"
>>> label   "Sampling"          parm {              name    "geo_velocityblur"
>>>                label   "Geometry Velocity Blur"                type
>>>  toggle          default { "0" }
>>>                range   { 0 1 }                 export  none
>>>  parmtag { "spare_category" "Sampling"
>>> }           }   }       group {             name        "folder0_2"
>>> label       "Dicing"
>>> parm {          name    "vm_shadingquality"             label   "Shading
>>> Quality"
>>>                type    float           default { "1" }
>>> range   { 0 10 }                export  none
>>>                parmtag { "spare_category" "Dicing" }       }       parm {
>>>                name    "vm_rayshadingquality"          label   "Ray Shading
>>> Quality"
>>>                type    float           default { "1" }
>>> range   { 0 10 }                export  none
>>>                parmtag { "spare_category" "Dicing" }       }   }
>>> group {
>>> name    "folder0_3"         label       "Geometry"          parm {
>>>                name    "vm_rmbackface"                 label   "Backface
>>> Removal (Mantra)"
>>>                type    toggle          default { "0" }
>>> range   { 0 1 }                 export  none
>>>                parmtag { "spare_category" "Geometry" }             }
>>> parm {
>>>                name    "shop_geometrypath"             label   "Procedural
>>> Shader"             type    oppath
>>>                default { "" }          range   { 0 1 }
>>> export  none            parmtag {
>>> "oprelative" "." }              parmtag { "opfilter" "!!SHOP/GEOMETRY!!" }
>>>                parmtag { "spare_category" "Geometry" }             }
>>> parm {
>>>                name    "vm_rendersubd"                 label   "Polygons As
>>> Subdivision (Mantra)"
>>>                type    toggle          default { "0" }
>>> range   { 0 1 }                 export  none
>>>                parmtag { "spare_category" "Geometry" }             }
>>> parm {
>>>                name    "vm_renderpoints"               label   "Render As
>>> Points (Mantra)"
>>>                type    toggle          default { "0" }
>>> range   { 0 1 }                 export  none
>>>                parmtag { "spare_category" "Geometry" }             }
>>> parm {
>>>                name    "vm_metavolume"                 label   "Metaballs
>>> as Volume"           type    toggle
>>>                default { "0" }                 range   { 0 1 }
>>>     export  none            parmtag {
>>> "spare_category" "Geometry" }       }       parm {              name
>>>  "vm_coving"
>>>                label   "Coving"                type    integer
>>>     default { "1" }                 menu    {
>>> "0"     "Disable Coving"                    "1" "Coving for
>>> displacement/sub-d"
>>> "2"     "Coving for all primitives"             }               range   { 0
>>> 10 }                export  none
>>>                parmtag { "spare_category" "Geometry" }             }
>>> parm {
>>>                name    "vm_computeN"           label   "Automatically
>>> Compute Normals"
>>>                type    toggle          default { "1" }
>>> range   { 0 1 }                 export  none
>>>                parmtag { "spare_category" "Geometry" }             }   }
>>>    }      group
>>> {       name    "stdswitcher5_3"        label   "Misc"          parm {
>>>  name        "use_dcolor"
>>>            baseparm        export      none    }       parm {      name
>>>    "dcolor"
>>> baseparm            export      none    }       parm {      name
>>>  "picking"           baseparm
>>>            export      none    }       parm {      name        "pickscript"
>>>        baseparm
>>> export  none    }       parm {      name        "caching"
>>> baseparm
>>> export  none    }       parm {      name        "vport_shadeopen"
>>> baseparm
>>> export  none    }       parm {      name        "vport_displayassubdiv"
>>>         baseparm
>>>            invisible       export      none    }     }  ' circle_cells
>>> opset -S on circle_cells
>>> opparm circle_cells use_dcolor ( off )
>>> chautoscope circle_cells +tx +ty +tz +rx +ry +rz +sx +sy +sz
>>> opset -d on -r off -h off -f off -y off -t off -l off -s off -u off -c
>>> off -e on -b off -x off circle_cells
>>> opexprlanguage -s hscript circle_cells
>>> opcf circle_cells
>>>
>>> # Node circle1 (Sop/circle)
>>> opadd -n circle circle1
>>> oplocate -x 3.41176 -y 0.0882355 circle1
>>> opparm circle1 type ( poly ) orient ( zx ) rad ( 21 21 ) divs ( 100 )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off circle1
>>> opexprlanguage -s hscript circle1
>>>
>>> # Node triangulate2d1 (Sop/triangulate2d)
>>> opadd -n triangulate2d triangulate2d1
>>> oplocate -x 3.41176 -y -1.15882 triangulate2d1
>>> opparm triangulate2d1 refine ( on ) maxarea ( 2 ) minangle ( 30 )
>>> maxnewpts ( 19565 ) removeduplicatepoints ( off )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off triangulate2d1
>>> opexprlanguage -s hscript triangulate2d1
>>>
>>> # Node facet1 (Sop/facet)
>>> opadd -n facet facet1
>>> oplocate -x 3.50951 -y -3.19412 facet1
>>> opparm facet1 unique ( on )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off facet1
>>> opexprlanguage -s hscript facet1
>>>
>>> # Node foreach1 (Sop/foreach)
>>> opadd -n foreach foreach1
>>> oplocate -x 3.41176 -y -5.02471 foreach1
>>> chblockbegin
>>> chadd -t 0 0 foreach1 numrange2
>>> chkey -t 0 -v 10 -m 0 -a 0 -A 0 -T a  -F 'nprims("../" + opinput(".",
>>> 0))-1' foreach1/numrange2
>>> chblockend
>>> opparm foreach1 fortype ( number ) numrange ( 0 numrange2 1 )
>>> opset -d on -r on -h off -f off -y off -t off -l off -s off -u off -c
>>> off -e on -b off foreach1
>>> opexprlanguage -s hscript foreach1
>>> opcf foreach1
>>>
>>> # Node each1 (Sop/each)
>>> opadd -n each each1
>>> oplocate -x 0.6102 -y 4.8513 each1
>>> chblockbegin
>>> chadd -t 0 0 each1 attribtol
>>> chkey -t 0 -v 0.001 -m 0 -a 0 -A 0 -T a  -F 'ch("../attribtol")'
>>> each1/attribtol
>>> chadd -t 0 0 each1 attribval1
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F 'stamp("..",
>>> chs("../forstamp") + "1", 0)' each1/attribval1
>>> chadd -t 0 0 each1 attribval2
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F 'stamp("..",
>>> chs("../forstamp") + "2", 0)' each1/attribval2
>>> chadd -t 0 0 each1 attribval3
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F 'stamp("..",
>>> chs("../forstamp") + "3", 0)' each1/attribval3
>>> chadd -t 0 0 each1 attrib
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F
>>> 'ifs(!!strcmp(chs("../fortype"), "attrib"), "", chs("../attrib"))'
>>> each1/attrib
>>> chadd -t 0 0 each1 group
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F
>>> 'ifs(!!strcmp(chs("../fortype"), "group"), "", stamps("..",
>>> chs("../forstamp"), ""))' each1/group
>>> chadd -t 0 0 each1 feedback
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F '!ch("../mergeresults")'
>>> each1/feedback
>>> chblockend
>>> opparm each1 feedback ( feedback ) group ( group ) attrib ( attrib )
>>> attribval ( attribval1 attribval2 attribval3 ) attribtol ( attribtol )
>>> forpath ( .. )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off each1
>>> opexprlanguage -s hscript each1
>>>
>>> # Node delete2 (Sop/delete)
>>> opadd -n delete delete2
>>> oplocate -x 0.6102 -y 3.89295 delete2
>>> chblockbegin
>>> chadd -t 0 0 delete2 rangeend
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F '$N' delete2/rangeend
>>> chadd -t 0 0 delete2 filter
>>> chkey -t 0 -v 1 -m 0 -a 0 -A 0 -T a  -F 'stamp("../", "FORVALUE", 0)
>>> == prim("../" + opinput(".", 0), $PR, "__primnum", 0)' delete2/filter
>>> chblockend
>>> opparm delete2 negate ( keep ) groupop ( filter ) filter ( filter )
>>> pattern ( "" )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off delete2
>>> opexprlanguage -s hscript delete2
>>>
>>> # Node fit1 (Sop/fit)
>>> opadd -n fit fit1
>>> oplocate -x 0.610753 -y 0.946953 fit1
>>> opparm fit1 stdswitcher ( 2 2 2 ) method ( interp ) orderu ( 3 )
>>> orderv ( 3 ) smooth ( 0.343 ) scope ( breakpnt ) dataparmv ( uniform )
>>> closeu ( wu ) closev ( wv ) corners ( on )
>>> opset -d on -r on -h off -f off -y off -t off -l off -s off -u off -c
>>> off -e on -b off fit1
>>> opexprlanguage -s hscript fit1
>>>
>>> # Node circle1 (Sop/circle)
>>> opadd -n circle circle1
>>> oplocate -x 3.01075 -y 3.7 circle1
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off circle1
>>> opexprlanguage -s hscript circle1
>>>
>>> # Node resample1 (Sop/resample)
>>> opadd -n resample resample1
>>> oplocate -x 0.622517 -y 2.92353 resample1
>>> opparm resample1 edge ( on ) dolength ( off ) dosegs ( on ) segs ( 2 )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off resample1
>>> opexprlanguage -s hscript resample1
>>>
>>> # Node delete1 (Sop/delete)
>>> opadd -n delete delete1
>>> oplocate -x 0.610753 -y 1.85283 delete1
>>> chblockbegin
>>> chadd -t 0 0 delete1 rangeend
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F '$N' delete1/rangeend
>>> chblockend
>>> opparm delete1 entity ( point ) groupop ( range ) range ( -1 rangeend )
>>> opset -d off -r off -h off -f off -y off -t on -l off -s off -u off -c
>>> off -e on -b off delete1
>>> opexprlanguage -s hscript delete1
>>> oporder -e each1 delete2 fit1 circle1 resample1 delete1
>>> opcf ..
>>>
>>> # Node __PRIMNUM (Sop/attribcreate)
>>> opadd -n attribcreate __PRIMNUM
>>> oplocate -x 3.41176 -y -4.07765 __PRIMNUM
>>> chblockbegin
>>> chadd -t 0 0 __PRIMNUM value1
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F '$PR' __PRIMNUM/value1
>>> chblockend
>>> opparm __PRIMNUM name ( __primnum ) varname ( __PRIMNUM ) class (
>>> primitive ) value ( value1 0 0 0 )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off __PRIMNUM
>>> opexprlanguage -s hscript __PRIMNUM
>>>
>>> # Node foreach2 (Sop/foreach)
>>> opadd -n foreach foreach2
>>> oplocate -x 3.50951 -y -2.29415 foreach2
>>> opparm foreach2 fortype ( number ) numrange ( 0 4 1 ) mergeresults ( off )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off foreach2
>>> opexprlanguage -s hscript foreach2
>>> opcf foreach2
>>>
>>> # Node each1 (Sop/each)
>>> opadd -n each each1
>>> oplocate -x 0.6102 -y 4.8513 each1
>>> chblockbegin
>>> chadd -t 0 0 each1 attribtol
>>> chkey -t 0 -v 0.001 -m 0 -a 0 -A 0 -T a  -F 'ch("../attribtol")'
>>> each1/attribtol
>>> chadd -t 0 0 each1 attribval1
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F 'stamp("..",
>>> chs("../forstamp") + "1", 0)' each1/attribval1
>>> chadd -t 0 0 each1 attribval2
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F 'stamp("..",
>>> chs("../forstamp") + "2", 0)' each1/attribval2
>>> chadd -t 0 0 each1 attribval3
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F 'stamp("..",
>>> chs("../forstamp") + "3", 0)' each1/attribval3
>>> chadd -t 0 0 each1 attrib
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F
>>> 'ifs(!!strcmp(chs("../fortype"), "attrib"), "", chs("../attrib"))'
>>> each1/attrib
>>> chadd -t 0 0 each1 group
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F
>>> 'ifs(!!strcmp(chs("../fortype"), "group"), "", stamps("..",
>>> chs("../forstamp"), ""))' each1/group
>>> chadd -t 0 0 each1 feedback
>>> chkey -t 0 -v 0 -m 0 -a 0 -A 0 -T a  -F '!ch("../mergeresults")'
>>> each1/feedback
>>> chblockend
>>> opparm each1 feedback ( feedback ) group ( group ) attrib ( attrib )
>>> attribval ( attribval1 attribval2 attribval3 ) attribtol ( attribtol )
>>> forpath ( .. )
>>> opset -d off -r off -h off -f off -y off -t off -l off -s off -u off
>>> -c off -e on -b off each1
>>> opexprlanguage -s hscript each1
>>>
>>> # Node divide2 (Sop/divide)
>>> opadd -n divide divide2
>>> oplocate -x 0.6102 -y 3.42343 divide2
>>> opparm divide2 convex ( off ) dual ( on )
>>> opset -d on -r on -h off -f off -y off -t off -l off -s off -u off -c
>>> off -e on -b off divide2
>>> opexprlanguage -s hscript divide2
>>> oporder -e each1 divide2
>>> opcf ..
>>> oporder -e circle1 triangulate2d1 facet1 foreach1 __PRIMNUM foreach2
>>> opcf ..
>>>
>>> opcf /obj
>>> opcf circle_cells
>>> opwire -n circle1 -0 triangulate2d1
>>> opwire -n foreach2 -0 facet1
>>> opwire -n __PRIMNUM -0 foreach1
>>> opcf foreach1
>>> opwire -n -i 0 -0 each1
>>> opwire -n each1 -0 delete2
>>> opwire -n delete1 -0 fit1
>>> opwire -n delete2 -0 resample1
>>> opwire -n resample1 -0 delete1
>>> opcf ..
>>> opwire -n facet1 -0 __PRIMNUM
>>> opwire -n triangulate2d1 -0 foreach2
>>> opcf foreach2
>>> opwire -n -i 0 -0 each1
>>> opwire -n each1 -0 divide2
>>> opcf ..
>>> opcf ..
>>> opcf $saved_path
>>>
>>> ######################################################
>>>
>>> 2009/8/5 Doug Struthers <dragonfly at dougstruthers.com>:
>>> > Thanks for your inputs.
>>> >
>>> > Since there do not need to be thousands of them I bet I can iterate on
>>> them
>>> > to get a close approximation without taking a long long time to compute.
>>> >
>>> > It is intriguing to think that there may be a function with dops that the
>>> > solution falls out of but I am still a way down the learning curve with
>>> all
>>> > the functionality that exists in vops let alone rolling my own.
>>> >
>>> > Cheers
>>> >
>>> > Doug
>>> >
>>> > On Wed, Aug 5, 2009 at 9:09 AM, Gene Dreitser <keyframe at rogers.com>
>>> wrote:
>>> >
>>> >>
>>> >> Might also be worth it to take a look at the output of the isooffset sop
>>> >> using the 'tetra-mesh' output type.  Tetra-type set to 'cubes'.
>>> >>
>>> >> While it will not pack perfectly, it DOES create a predictable pattern
>>> of
>>> >> rows and columns that one might be able to make use, and as an added
>>> bonus,
>>> >> it can use ray-intersect to sample the original mesh.
>>> >>
>>> >> Best,
>>> >>
>>> >> G
>>> >>
>>> >>  --
>>> >> Gene Dreitser
>>> >> Loki Visual Effects
>>> >> p: 416.532.5654 // c: 416.803.0682 // www.lokivfx.com
>>> >>
>>> >>
>>> >>
>>> >> ----- Original Message ----
>>> >> From: Andy Nicholas <andy at andynicholas.com>
>>> >> To: sidefx-houdini-list at sidefx.com
>>> >> Sent: Wednesday, August 5, 2009 12:05:13 PM
>>> >> Subject: Re: [Sidefx-houdini-list] Space filling circles
>>> >>
>>> >> Hi Doug,
>>> >> Are you asking this because you know of this being done somewhere else?
>>> I
>>> >> only ask because I just Googled this (out of my own interest), and
>>> judging
>>> >> on how many papers are written on this topic, I'd say that it's a
>>> >> non-trivial problem to solve.
>>> >>
>>> >> The only thing that springs to mind, would be to create an iterative
>>> >> approach, using the SOP solver or the Feedback SOP (proto_install).
>>> >>
>>> >> Note that I haven't tested this, or fully thought it through, but the
>>> >> following... might... just...  work...
>>> >>
>>> >> Start off with a triangular polygon with a random sized disc at each
>>> >> vertex so that their circumferences touch. From that, take a pair of
>>> discs
>>> >> and create another randomly sized one and place it (using simple
>>> >> trigonometry) so that it touches the first two. Extend the triangle into
>>> a
>>> >> four sided polygon with the new point at the center of the new disc.
>>> >> Repeat the process, but ignoring any discs internal to the polygon.
>>> >>
>>> >> I can see this approach breaking down if you ever have a non-convex
>>> >> polygon, but there are probably some constraints that you could figure
>>> out
>>> >> that will prevent this from happening.
>>> >>
>>> >> Andy
>>> >>
>>> >>
>>> >>
>>> >>
>>> >> > Hi
>>> >> >
>>> >> > Can anyone point me to a Houdini method (or other solution) for
>>> packing
>>> >> > random sized circles so that they are tightly packed and each
>>> >> > circumference
>>> >> > just touches its neighbors?
>>> >> >
>>> >> > Thanks
>>> >> >
>>> >> > Doug
>>> >> >
>>> >> > --
>>> >> > www.dougstruthers.com
>>> >> > _______________________________________________
>>> >> > Sidefx-houdini-list mailing list
>>> >> > Sidefx-houdini-list at sidefx.com
>>> >> > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>> >> >
>>> >>
>>> >>
>>> >> _______________________________________________
>>> >> Sidefx-houdini-list mailing list
>>> >> Sidefx-houdini-list at sidefx.com
>>> >> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>> >>
>>> >> _______________________________________________
>>> >> Sidefx-houdini-list mailing list
>>> >> Sidefx-houdini-list at sidefx.com
>>> >> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>> >>
>>> >
>>> >
>>> >
>>> > --
>>> > www.dougstruthers.com
>>> > _______________________________________________
>>> > Sidefx-houdini-list mailing list
>>> > Sidefx-houdini-list at sidefx.com
>>> > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>> >
>>>
>>>
>>>
>>> --
>>> =======================================
>>> Andrew D Lyons | Digital Artist | http://www.tstex.com
>>> =======================================
>>> _______________________________________________
>>> Sidefx-houdini-list mailing list
>>> Sidefx-houdini-list at sidefx.com
>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>> _______________________________________________
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>>> Sidefx-houdini-list at sidefx.com
>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>>
>> _______________________________________________
>> Sidefx-houdini-list mailing list
>> Sidefx-houdini-list at sidefx.com
>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>
>
>
>
> --
> =======================================
> Andrew D Lyons | Digital Artist | http://www.tstex.com
> =======================================
>



-- 
=======================================
Andrew D Lyons | Digital Artist | http://www.tstex.com
=======================================



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