How would you POV-Ray gurus do a bent rebar.

So for example a straight section, then a 90 degree smooth bend (with some
bending radius), another straight section, another bend (for example a U
with a flat bottom).

I tries with a sphere-sweep and a cubic spline, but this does not give me
the ability to specify the bend radius and I was unable to produce a smooth
shape. I really do not want to have to specify the bend points explicitly.

I want to be able to specify the shape descriptively. For example, 0.5
straight, 90 degree bend (downwards) with bend radius of 0.2, 1.0 straight,
90 degree bend (upwards) with bend radius of 0.3.

Is there a way?

Thanks,

dave

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Dave wrote:

> How would you POV-Ray gurus do a bent rebar.
> 
> So for example a straight section, then a 90 degree smooth bend (with some
> bending radius), another straight section, another bend (for example a U
> with a flat bottom).
> 
> I tries with a sphere-sweep and a cubic spline, but this does not give me
> the ability to specify the bend radius and I was unable to produce a smooth
> shape. I really do not want to have to specify the bend points explicitly.
> 
> I want to be able to specify the shape descriptively. For example, 0.5
> straight, 90 degree bend (downwards) with bend radius of 0.2, 1.0 straight,
> 90 degree bend (upwards) with bend radius of 0.3.
> 
> Is there a way?
> 
> Thanks,
> 
> dave

I'm not so sure this is the right group to be asking this....

Anyway, to make such bent rebar I would contruct it out of clipped torii 
and cylinders. A simple bar with a radius-2 bend at the beginning would 
look something like this:

union{
  cylinder{0,x*3,.1}
  torus{2,.1
   clipped_by{
    box{
     <-2.5,-.2,-2.5>,<0,.2,0>
    }
   }
   rotate x*270 translate y*2
  }
  pigment{rgb .13}
}

Please note that using clipped torii and cylinders in this manner will 
render more quickly than using a sphere_sweep.

-Sam

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i came across this problem quite a few times before, so i decided to make a
macro which does this automaticly. It is finished (only 2D), but not ready
for publishing. This weekend i shall finish the 2D version, 3D version is a
bit more difficult.

Greetings,

JWV

"Dave" <DAn### [at] Genifycom> wrote in message
news:413fd593@news.povray.org...
> How would you POV-Ray gurus do a bent rebar.
>
> So for example a straight section, then a 90 degree smooth bend (with some
> bending radius), another straight section, another bend (for example a U
> with a flat bottom).
>
> I tries with a sphere-sweep and a cubic spline, but this does not give me
> the ability to specify the bend radius and I was unable to produce a
smooth
> shape. I really do not want to have to specify the bend points explicitly.
>
> I want to be able to specify the shape descriptively. For example, 0.5
> straight, 90 degree bend (downwards) with bend radius of 0.2, 1.0
straight,
> 90 degree bend (upwards) with bend radius of 0.3.
>
> Is there a way?
>
> Thanks,
>
> dave
>
>

Post a reply to this message