2008

All the current attributes are String type attributes that are stored in the
header for the file, and can be read in plain text via the exrheader.exe utility
(available from http://www.openexr.com/the official Website > Downloads
page).
Attributes and channels are stored in the file in alphabetical order according
to the ASCII file tag.
While this plug-in can write most of the 3ds Max G-Buffer on page 7795
channels, there is no software that can utilize them yet.
Attributes and channels are identified by plain-text (ASCII) strings. There
can be only one instance of a string tag in any file. Attributes are data that
is stored per frame, not per pixel, and they are embedded in the file's
header. Channels are data that is stored per pixel. In order to maximize
flexibility with other software, this plug-in lets you edit the file tags. You
should only do this if you know the tag required by some other software;
otherwise it is best to leave the file tags at their default values.
Channels that create multiple slices in the EXR file require multiple file
tags. In this case, the file tag in the user interface comprises several sub-tags
denoted by square brackets. For example, the Normal channel generates
three slices in the EXR file: one for the Normal vector x data, 1 for y, and
1 for z. In this instance, the tag string in the user interface would read
[NX][NY][NZ], and generate slices with the file tags "NX", "NY", and "NZ".
The file tag is used by software that is reading the EXR file to identify the
intended use of the channel data. Even standard image channels are
encoded this way, with the tags "R", "G", "B", and "A" used to denote red,
green, blue, and alpha channels respectively.
Extended Attributes
Comment A general-purpose comment string defined by the user. To define
the comment, highlight the Comment entry in the list and then edit the
Comments field immediately below the list.
Computer Name The name of the computer the image was saved from. In
the case of standard render output during a net render, this is the machine
that rendered the frame.
System Time The UTC (GMT) system time and date when the file was written.
Local Time The local time and date (corrected for the time zone) when the
file was written.
7146 | Chapter 21 Managing Scenes and Projects