"Rune" <new### [at] runevisioncom> wrote:
> I tried to use subsurface scattering (sss) for the pistil and stamens but it
> is behaving oddly. It creates bright pixels near the edge of the object, and
> it also seem that blobs with sss look brigher than sphere_sweep with sss for
> some reason. The bright end of the pistil is a blob while the rest is a
> (straigt for now) sphere_sweep. I'm considering just dropping sss when it
> creates so much trouble.

If you are using media for the SSS, then:

I don't know about sphere sweeps, but if I remember correctly the spurious
bright pixels around the edges of scattering media-filled blobs have been
described before somewhere in these NG. If I remember right, the problem
was intersection calculation inaccuracies in the blob object. A ray being
traced through the blob interior near its edge would fail to find the exit
intersection, and so the media code would decide it was facing a very long
ray and a correspondingly large amount of scattering medium -> brightness.

I *think* there was a solution; you specify the blob component sizes on a
larger scale, so instead of a spherical component with radius 0.1, you'd
use radius 10 and scale the blob down or the whole of the rest of the scene
up by a factor of 100 to compensate. I can't remember whether either option
(down-scaling or up-scaling) was preferred over the other. I also can't
remember whether a radius  of 10 was sufficient to avoid the problems, but
I guess it would be easy to make a quick test scene and find out.

You might also fake SSS instead by using megapov's AOI pattern to add light
near the edges of the object, but I have never tried this.

Tom

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