[Sidefx-houdini-list] Space filling circles

Steve Tucker Steve.Tucker at Starz.com
Thu Aug 6 09:58:29 EDT 2009


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



More information about the Sidefx-houdini-list mailing list