What im doing is essentially making a strand of DNA. ive got my spheres as 
molecules of A,C,G,T and a bar connecting them.  They are being generated
by a while loop.  Its all working fine but i cant rotate them properly.  

i was trying to use a rotation and then a translation to get the 2 spheres
and bar in line with the rest of them but that will only work for certain
angles and then i would have to figure out the translation again.

Anyone have a  general formula? Im looking for some sort of sinusoidal
equation i think.  Just cant put two and two together.

so if the camera was directly atop the strand of DNA and the desired angle 
was 90 degrees it would look like this

     O
      |
0=====0
      |
     O

i know this is damn confusing.  if anyone wants to see the source let me
know and ill email it.

Thanks so much

-- 
Zack Halbrecht
Head Procrastinator
Rutgers University
zac### [at] edenrutgersedu

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"Zack Halbrecht" <zac### [at] edenrutgersedu> writes:
> 
> What im doing is essentially making a strand of DNA. ive got my spheres as 
> molecules of A,C,G,T and a bar connecting them.  They are being generated
> by a while loop.  Its all working fine but i cant rotate them properly.  
> 
> i was trying to use a rotation and then a translation to get the 2 spheres
> and bar in line with the rest of them but that will only work for certain
> angles and then i would have to figure out the translation again.
> 

Perhaps I'm getting you wrong, but why not do it like this

union {
  #declare step=0
  #while (step<max_step)
    union {
      sphere { <-10,step,0>, 1 pigment { color your_color } }
      sphere { < 10,step,0>, 1 pigment { color your_color } }
      cylinder { <-10,step,0>, <10,step,0>, 0.5 pigment { color your_color } }
      rotate 10*step*y
    }
    #declare step = step+1
  #end
  scale ...
  rotate ...
  translate ...
}

This is just to give you an idea. Of course you have to fill in the colors
and adjust the sizes of the object. 

I hope this helps

ThW

-- 
Tho### [at] uni-konstanzde
http://www.informatik.uni-konstanz.de/~willhalm/
Tschieses lavs ju

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Why not download a real DNA double helix chain?  Search for PovChem or
PDB.  PovChem produces excellent results.  You can also find PovChem on
www.povray.org  Just a thought anyway...

--
Lance Birch
Remove the smiley to e-mail.
http://www1.tpgi.com.au/users/ambient/lance

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Try using the "tower.inc" file.  I was playing around with a helix form with
it a while ago and it seemed to work perfectly.  The form in my tower image
at: http://student.canberra.edu.au/~u982555/mystuff.html started out as a
regular helix. I hope this helps.

Roger
































Zack Halbrecht wrote:

> What im doing is essentially making a strand of DNA. ive got my spheres as
> molecules of A,C,G,T and a bar connecting them.  They are being generated
> by a while loop.  Its all working fine but i cant rotate them properly.
>
> i was trying to use a rotation and then a translation to get the 2 spheres
> and bar in line with the rest of them but that will only work for certain
> angles and then i would have to figure out the translation again.
>
> Anyone have a  general formula? Im looking for some sort of sinusoidal
> equation i think.  Just cant put two and two together.
>
> so if the camera was directly atop the strand of DNA and the desired angle
> was 90 degrees it would look like this
>
>      O
>       |
> 0=====0
>       |
>      O
>
> i know this is damn confusing.  if anyone wants to see the source let me
> know and ill email it.
>
> Thanks so much
>
> --
> Zack Halbrecht
> Head Procrastinator
> Rutgers University
> zac### [at] edenrutgersedu

Post a reply to this message