[Fluxus] voxels and blobby commits

[evan.raskob [lists]]

**slaps forehead**

i thought you were posting the script from your blog example...
guess that's why skimming emails before replying is not recommended :)

thanks Dave, you da man!

cheers
Evan




On Feb 2, 2010, at 12:18 PM, Dave Griffiths wrote:

> That's what that script does. You can make it into a function if you
> like? :)
>
> cheers,
>
> dave
>
> On Tue, 2010-02-02 at 12:15 +0000, evan.raskob [lists] wrote:
>> This is great but when do we get the holy grail of poly->voxels?? :)
>>
>>
>>
>>
>> On Feb 2, 2010, at 10:04 AM, Dave Griffiths wrote:
>>
>>> Hi all,
>>>
>>> I've added a (voxel->blobby) command to so we can use the marching
>>> cubes
>>> meshing algorithm to create polygon solids from voxels. I've also
>>> updated the documentation a little for the voxels.
>>>
>>> I also stumbled across some strange new effects:
>>> http://www.pawfal.org/dave/blog/category/accidental-art/
>>>
>>> Here is a script for converting polygons into voxels - thus  
>>> completing
>>> the circle:
>>>
>>> (clear)
>>> (clear-colour 0.5)
>>>
>>> ; load the polygon object
>>> (define poly (with-state
>>>   (scale 2) ; make it fit nicely within the voxels area
>>>   (load-primitive "bot.obj")))
>>>
>>> ; apply the fitting transform
>>> (with-primitive poly (apply-transform))
>>>
>>> ; make some voxels
>>> (define v
>>>   (with-state
>>>       (blend-mode 'src-alpha 'one)
>>>       (hint-nozwrite)
>>>       (texture (load-texture "splat.png"))
>>>       ; move around the polygon object
>>>       (scale 8)
>>>       (translate (vector -0.5 -0.5 -0.5))
>>>       (build-voxels 50 50 50)))
>>>
>>> ; utils - need to put these somewhere else
>>> (define (voxels-index x y z)
>>>   (+ x (* y (voxels-width)) (* z (voxels-width) (voxels-height))))
>>>
>>> (define (voxels-pos i)
>>>   (vdiv (vector (modulo i (voxels-width))
>>>           (modulo (quotient i (voxels-width)) (voxels-height))
>>>           (quotient i (* (voxels-width) (voxels-height)))) (voxels-
>>> width)))
>>>
>>> ; for each voxel, check for odd or even intersection counts against
>>> the poly
>>> (with-primitive v
>>> (pdata-index-map!
>>>    (lambda (i c)
>>>         (let ((p (vtransform (voxels-pos i) (get-transform))))
>>>             (if (odd? (length (with-primitive poly (geo/line-
>>> intersect (vector 0 1 -1000) p))))
>>>                   (vector 1 1 1 1) ; inside
>>>                   (vector 0 0 0 0)))) ; outside
>>>       "c")
>>>   ; the rest of this is to make it look pretty for previewing
>>>   (voxels-calc-gradient)
>>>   (pdata-copy "g" "c")
>>>   (pdata-map!
>>>       (lambda (c)
>>>           (if (< (vmag c) 0.1)
>>>               (vector 0 0 0 0) c))
>>>       "c"))
>>>
>>> (destroy poly)
>>>
>>> ; convert to a blobby
>>> (define bp
>>>   (with-state
>>>       (hint-unlit) ; again all this
>>>       (colour 1)   ; just for
>>>       (hint-wire)  ; preview rendering
>>>       (voxels->blobby v)))
>>> (destroy v)
>>>
>>> (define pp (blobby->poly bp))
>>> (destroy bp)
>>>
>>> (with-primitive pp
>>>   (recalc-normals 1))
>>>
>>>
>>>
>>
>