hello.

i have one problem with torus.

let say that we have a form defined like this :
  union {
    cylinder { }
    object { torus_segment }
    cylinder { }
    object { torus_segment }
    cylinder { }
    }
  
major radius is 180, minor radius and cylinder radius is 20.
camera is at <1000, 1000, 1000> and look at <0, 0, 0>.

when rendering this object, no torus is draw !!! (first attached image)

so what ?
if i put camera at <1000, 1000, 1000>*0.60, torus are here (second image).

and so on. let build the bonding box of this object :
box {
  min_extent(sForm) max_extent(sForm)
  pigment { rgbt 1 }  <-- 'invisible pigment
  }

rendering with camera at <1000, 1000, 1000> show torus...
(third attached image)

it's a bug or i am wrong ?
i use mac megapov 1.0 30-dec-2002.

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Attachments:
Download 'no_torus.JPG' (5 KB) Download 'camera.JPG' (8 KB) Download 'bondingbox_torus.JPG' (6 KB)

Preview of image 'no_torus.JPG'

Preview of image 'camera.JPG'

Preview of image 'bondingbox_torus.JPG'

kur### [at] yahoofr
news:kur### [at] netplexaussieorg 

> hello.

Can You post short example sample code (complete)?


-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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Toruses are fourth-order equations, so they require numbers fairly close to
zero in order to avoid floating point innacuracies. When the camera is too
far away from them, innacuracies are introduced, and the toruses won't be
displayed properly.

If you can live with a closer camera, do that. If not, I believe someone
somewhat recently posted a patch which causes toruses to render more
accurately but more slowly (by bringing the camera closer on a per-sample
level).

 - Slime
 [ http://www.slimeland.com/ ]

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Please see this torus bug fix:
http://www.hassings.dk/l3/povtorus/povtorus.html
/Lars

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