Re: AW: [Openexr-devel] Missing include - and other questions...

[Drew Hess]

p.s this particular shader is for displaying a 2D HDR image using a 
tonemap in a LUT, but the LUT trick could be incorporated into any shader.


-dwh-


On Mon, 26 Jan 2004, Drew Hess wrote:

> 
> Hi Matthias,
> 
> If you have a programmable GPU available with support for 16-bit FP
> pixels, you can do a neat trick with a Cg shader and a 16-bit lookup
> table.  Assuming you can bake your tonemap into the table and you have the
> right hardware, this is pretty fast.
> 
> I've attached the Cg shader that does this.
> 
> 
> -dwh-
> 
> 
> 
> On Mon, 26 Jan 2004, Matthias Biedermann wrote:
> 
> > Hi folks,
> > 
> > 
> > thanks for your quick answers!
> > 
> > Well, I've already investigated into that tone-mapping stuff and have
> > found Reinhard's technique implemented in your toolset "exrtools",
> > Billy. 
> > However, the tonemapping needed for my work (which will finish in the
> > midst of June...) is just for displaying the HDR as textures, so
> > "business as usual". The "problem" is that tonemapping is not the main
> > focus of my thesis and thus doesn't have to be very sophisticated but
> > rapid. As I'm dynamically rendering HDR-cubemaps in moving/interactive
> > scenes lit by a static (but rotateable/exchangeable) HDR-lightprobe
> > there is not much time to use clever multipass operators and such - the
> > GPU will have enough fun with the spherical harmonics anyway...;->
> > 
> > So if you can recommend or tell about experiences with some fast global
> > tonemapping operators like some sort of log-mapping
> > (Weber-Fechner's-law, global step of Reinhard's) or (N)URQV, I'd be
> > happy about any information!
> > 
> > 
> > Bye,
> > Matthias
> > 
> > 
> > 
> > 
> > > -----Ursprüngliche Nachricht-----
> > > Von: Billy Biggs [mailto:address@hidden 
> > > Gesendet: Montag, 26. Januar 2004 21:46
> > > An: Matthias Biedermann
> > > Cc: address@hidden
> > > Betreff: Re: [Openexr-devel] Missing include - and other questions...
> > > 
> > > 
> > > Florian Kainz (address@hidden):
> > > 
> > > > > btw: I'm very delighted to have found such a flexible and 
> > > extensible 
> > > > > open-source tool for handling HDR-images as I need them 
> > > (along with 
> > > > > other stuff) in my diploma thesis. Is there already more 
> > > information 
> > > > > available for using OpenEXR with dynamic rendering of cubemaps as 
> > > > > XXXXX has asked ...? Or some general "paper"-stuff about 
> > > OpenEXR and 
> > > > > its concepts (like tonemapping etc.) to use for citations?
> > > > 
> > > > [...]
> > > >
> > > > No tone-mapping techniques I know of depend on a particular 
> > > image file 
> > > > format.  The only requirement is, of course, that the input 
> > > files must 
> > > > be able to represent the image's full dynamic range.  For various 
> > > > papers about tone mapping, check the SIGGRAPH proceedings 
> > > from 1998 to 
> > > > 2003.
> > > 
> > >   Techniques don't depend on a file format, but implementations
> > > sometimes do. ;-)   I implement some tone mapping algorithms in
> > > exrtools, and will post improved versions soon.
> > > 
> >   http://scanline.ca/exrtools/
> > 
> >   -Billy
> > 
> > 
> > 
> > _______________________________________________
> > Openexr-devel mailing list
> > address@hidden
> > http://mail.nongnu.org/mailman/listinfo/openexr-devel
> > 
> > 
> > 
>