Hi Bob!

Thanks for you answer!

> tightness 1, or a very small number. I've used less than 1 even
> though the Doc says 1 to 100. Remember that tightness 100
> concentrates toward the radius fading the falloff, tightness 1
> concentrates toward falloff diameter. For cylinder lights this is a
> bit less straightforward to me, and others too apparently, since the
> values for radius and falloff don't result in the same area of
> projection.
Do you mean that the angle (or whatever with cylinder) shouldn't be the same
for falloff and radius - in difference to the spotlight-case?
Well, at least it seams that way...

> I can't recall what, if any, explanation is for the
> differences except maybe it has to do with the cone angle versus
> cylinder being a diameter. 0 to 1 (something) perhaps, instead of 0
> to 360 degrees? But I'm conjecturing. I notice it isn't stated in the
> Doc.
I tried with very tiny values for tightness - but no sharp corners...

Here is a short scenefile that shows my problem:
the right side is what I wanted, the left side is how far I came wihth
cylinder... :-(

///begin
plane {y,0 texture{ pigment{ checker color rgb 1 color rgb .8 scale 5}}}
light_source {<0,100,0>color rgb .1}

light_source {
  <-50,50,0>
  color rgb 1
///  spotlight
  cylinder
  point_at <-5,0,0>
  falloff 5
  radius 5
  tightness .000000000000000001
}

light_source {
  <5,50,0>
  color rgb 1
  spotlight
///  cylinder
  point_at <5,0,0>
  falloff 5
  radius 5
///  tightness .0000000000001
  tightness 100
}

camera {
  location <-0,15,-1>
  look_at <-0,0,0>
}
///end

I will have a look in the Povray source, one day, to understand this strange
(at least for me) behaviour...

I hope, you don't mind this short piece of code.

cukk

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