Re: [Openexr-devel] Unit scale for Z values

[Larry Gritz]

I'm not sure if this addresses your question directly (which seemed to be more 
about automatic conformance to a unit scale upon read/write?), but as far as 
converting the values of a deep file that already exists:

If you know that the z's are in decimeters and you want to convert to meters, 
and you know the channels of the file (let's say that you know that there are 
two channels, "A" and "Z"), you can do

    oiiotool decimeters.exr -mulc 1.0,10.0 -o meters.exr

Basically just multiplying every alpha value by 1.0 (keeping it the same) and 
multiplying every Z value by 10.0 (converting decimeters to meters).

Sorry, I just checked and the deep support for "-mulc" is a recent addition, at 
this moment is in the "master" branch only. But I can backport it to a stable 
release branch if people need it.


> On Jan 13, 2016, at 12:27 PM, Jason Iversen <address@hidden> wrote:
> 
> Hi all,
> 
> Is there any mechanism in place, or planned, or rejected(!), for adjusting 
> (deep) Z values to match a unit scale? In environments where you interchange 
> deep EXR2's between packages which are working in different unit scales (eg. 
> Maya in decimeters and Houdini in meters) you would want to convert to the 
> unit scale to the hosted application upon read. I'd imagine you'd do this be 
> comparing it to a unit-scale stored in metadata.
> 
> Regards,
> Jason
> 
> 
> -- 
> Jason Iversen
>   Production Technology Supervisor
>     Digital Domain
> 

--
Larry Gritz
address@hidden