Nieminen Mika wrote:
> 
> Ken <tyl### [at] pacbellnet> wrote:
> : I disagree with your statement. I just ran three tests of unions vs. meshs
> : of triangles and the unions in all three cases parsed and rendered faster.
> : Meshs seem to only have the advantage of memory optimization when using
> : multiple copies of the same mesh object.
> 
>   This test seems extremely strange since my experience states the contrary.
>   The lparser program produces a union of triangles. The parsing time
> usually blows up in the "creating light buffers" stage (several minutes
> in my old 486; not tested in my new P-II). Substituting "union" with "mesh"
> reduced that stage to seconds.
>   Also the faster rendering time seems strange since AFAIK povray generates
> an efficient octree (or a similar data structure) from the mesh while it
> can't do that with a union of objects. Testing ray-triangle intersections
> is much more faster with that kind of data structure.
>   I have to test this by myself...
> 
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

  Even stranger still is that the UV patch takes even longer to parse
and render a mesh vs. a union of triangles than the official version.
One quick test showed a 670 triangle object render in 22 sec within a
union but took 33 sec. in a mesh.
  Worthy of note is that the memory usage heavily favored the mesh
object. The mesh used a peak memory of something like 122k while the
union consumed a peak of 170k.

-- 
Ken Tyler

mailto://tylereng@pacbell.net

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