This document describes the standard metadata that is included in all DIRSIG HDF files and give context on the type and contents of the file. Specific files may add to this metadata without an issue. There are currently two strategies for encoding this metadata. The first is to encode the following as data sets in a /Info group. The second is to encode the following as attributes on the document root (normally the file). The attribute approach is favored and data models are being converted to this approach.

FileType

Data Type

NATIVE_UINT

Dataspace Type

Simple

Dimensions

1

Required

Yes

Holds the type of the HDF file. The types are as follows:

Value File Type

0

Scene Definition

1

Four Curve Atmosphere Database

2

Background Sky Database

3

Material Bundle

4

Shadow History Database

5

NewAtmosphere Database

FormatVersion

Data Type

NATIVE_UINT

Dataspace Type

Simple

Dimensions

1

Required

Yes

Holds the version of this file. The meaning of this version is specific to the type of file.

Name

Data Type

StrType (C_S1, Variable)

Dataspace Type

Simple

Dimensions

1

Required

Yes

Holds the name of this file. Each file type is free to populate this as they see fit and may have naming conventions that will be documented in that file type’s ICD.

Description

Data Type

StrType (C_S1, Variable)

Dataspace Type

Simple

Dimensions

1

Required

No

Holds a description of this file. This dataset should be used to give more context to the contents of the file beyond Name.

Author

Data Type

StrType (C_S1, Variable)

Dataspace Type

Simple

Dimensions

N

Required

Yes

Holds a list of author(s) for this file. This dataset should be used for tracking the origins of the contained data.

Organization

Data Type

StrType (C_S1, Variable)

Dataspace Type

Simple

Dimensions

N

Required

No

Holds a list of organizations(s) that produced this file. This dataset should be used for tracking the origins of the contained data.