See my responses below.

"sooperFoX" wrote:
> Hi Dave,
>
> I am at work so I can't test it right now, but just reading through that
> file it looks like you do have coincident surfaces going on with the base
> of the cone and the plane. The cone has its base at <0, 0, 0> which is then
> translated to <-8, -1, 17>, while the plane is defined at y = -1.


I can confirm this now. I get the same result as you when rendering your
scene unmodified.


> Either move the cone up a small amount:
> cone
> {
>   <0,0,0>, 5.5, <0,11,0>, 0
>   translate <-8, -1, 17>
>   translate 0.01*y /* add this line to move the cone up from the plane */
>   texture {
>     ...
>   }
>   ...
> }


Tried this. See first attached image. No speckles now, but a large black
area appears in the lower region of the cone.

I assumed this had something to do with max_trace_level, so I increased it
to 255 (outside the photons block). This didn't really remove the black
area but I got some more internal reflections happening now. See second
image.


So then I tried something I remember reading when I was messing around with
water inside a drinking glass - putting the surfaces inside each other
rather than separate. So, I moved the cone *down* slightly (translate
-0.01*y) instead of up, and bingo. See the third image. I think this is
what you're after, no?


-- sooperFoX

EDIT: second and third images will have to go in subsequent posts, because I
can't seem to attach more than one at a time through the web interface.

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