[Bf-committers] Realistic materials question (Farsthary)

[Brecht Van Lommel]

Hi,

On Mon, 2009-02-23 at 17:55 -0500, Yves Poissant wrote:
> >  also I need good formulas for implementing tone mappers because path
> > tracer images fall outside the (0,1) range.
> 
> While it is nice to have a tone mapping algo, you can run quite some mileage 
> with a very simple multiplier (for controling the exposure) followed by a 
> simple gamma correction. This simple scheme has the added advantage that you 
> don't have to wonder at the (sometime quite weird) idiosyncrasies of the 
> tone mapping algo. Whatever you choose, I would suggest you save your 
> renders to a floating point file format such as OpenEXR. Then, you can 
> experiment with different tone mapping algos. For the algos, here is a good 
> place to start:
> http://www.mpi-inf.mpg.de/resources/tmo/

The compositor has a Tonemap node, implementing I think the following
algorithms:

E. Reinhard and K. Devlin, "Dynamic Range Reduction Inspired by
Photoreceptor Physiology"
E. Reinhard, M. Stark, P. Shirley, and J. Ferwerda, "Photographic Tone
Reproduction for Digital Images"

Since Blender outputs unclamped floats into the compositor these should
work fine for your purpose I think.

Brecht.