Thorsten Froehlich <tho### [at] trfde> wrote:
> Warp wrote:
> > andrel <a_l### [at] hotmailcom> wrote:
> >> Just curious, why should it not be evenly distributed
> > 
> >   Because the diffuse illumination of a surface depends on the angle from
> > which the light is coming: The more perpendicular the incoming light is to
> > the surface, the stronger its contribution. The strength of the contribution
> > decreases as a function of the cosine of the angle. If the incoming light
> > is parallel to the light, it has zero contribution.

> In theory the contribution is zero, in reality it is not though, due to the 
> lack of perfectly flat surfaces. Micro-facets and a high-intensity light 
> source can have surprising effects...

  But we are talking about simple diffuse lighting here... :P

> However, the probability that small area but high intensity contributions 
> are missed increases with the unevenness of the distribution (because it is 
> a function of the sample density).

  I wonder if adaptive supersampling (similar to what is used in antialiasing
method 2 and adaptive area lights) could be used in the stochastic sampling:
If the brightness of two adjacent samples differ more than a given threshold,
take an additional sample between them.

-- 
                                                          - Warp

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