Krita use in VFX

[Cyrille Berger]

> that sounds nice but it doesn't allow for painting with absolute values
> in the float/HDR case and it doesn't allow negative/out of range values
> unless I miss something.

Sure it does :) It's just is limited to the range currently "visible". In your 
sun example, with a non HDR monitor, you move slider until you can see the 
sun, and then you select colors and can draw on the sun. But maybe we need 
both way.

> I think the best way would be to be able to have:
>
> Image display:
>    * Raw (unaltered, clamped to target display's capability --
>        there are HDR monitors btw! :) )
It's unrealistic to really say we support HDR monitors without access to 
one :)

>    * Exposure-based
>    * Normalized (between a user-specified black & white points)
>        This is very useful to e.g work on a non-normalized 32bit float
>        displacement map. Since this will inevitably contain negative
>        values and values outside of 0..1, being able to work on this just
>        as it were a greyscale image would be a very kewl feature.
>
> Colour sliders:
>    * 0..255
>    * 0..100%
>    * 0..1
>
>    A checkbox saying 'Absolute' which, if turned off, would apply the
>    normalization you talk about above.
I failed to see how with a color slider of 0..1 you can select negative and 
out of range values ?

> In any case, values outside the range must be allowed both positive and
> negative. In VFX we do paint negative values into HDR images to suck
> light when using them for lighting ojects in 3D. And we do e.g. paint
> the sun into a HDR sky -- The sun is *a lot* brighter than the sky
> (100000 times, sometimes). So I need to be able to paint with a colour
> of 100000. :)
> Currently I need to go to Shake to do this sort of stuff... :|
>
> >> That sounds awesome. I contacted some people for some more info on TIFF
> >> tags. There's e.g. tags in TIFF that tell an app to flip the image
> >> vertically or horizontally etc.
> >
> > Like this one
> > http://www.awaresystems.be/imaging/tiff/tifftags/orientation.html ? :)
>
> Yep. That's them! :)
The problem with that kind of tags is that without examples files I fear to do 
something more wrong than ignoring them.

-- 
Cyrille Berger