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

[Jason Iversen]

Hi Larry,

Thanks, and yes - I was one of the people who at least chorused with the request to be able to apply a z-scale within oiiotool.  We just installed 1.6.9 here; does that have the -mulc feature?

My question is definitely aimed at the idea of support for automatic conformance to try to aid interchange without incurring pipelining - ie, tracking of originating scale and destination scale, and generating intermediates.

Thanks,

Jason

PS.  I have the same question poised for Alembic :)

On Thu, Jan 14, 2016 at 11:13 AM, Larry Gritz <address@hidden> wrote:

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

--

Jason Iversen

  Production Technology Supervisor

    Digital Domain