API Reference — `dna/layers/DescriptorWriter`

`class DNAAPI DescriptorWriter : public HeaderWriter`

Write character and rig metadata — identity, coordinate conventions, LOD range, and database provenance — into a DNA asset.

When to use this

Use this interface when populating or updating the descriptor layer of a DNA file: setting the character's name, archetype, gender, age, coordinate frame, available LOD levels, and database origin. All setter methods are pure-virtual; obtain a concrete instance through a Writer subclass — not by subclassing DescriptorWriter directly.

Method groups

Group	Methods
Identity	`setName`, `setArchetype`, `setGender`, `setAge`
Metadata	`clearMetaData`, `setMetaData`
Units & coordinate system	`setTranslationUnit`, `setRotationUnit`, `setCoordinateSystem`, `setRotationSequence`, `setRotationSign`, `setFaceWindingOrder`
Level of detail	`setLODCount`, `setDBMaxLOD`
Database	`setDBComplexity`, `setDBName`

Example

// Obtain a writer from BinaryStreamWriter or equivalent Writer subclass.
// DescriptorWriter* dw = writer->getDescriptorWriter();

dw->setName("Ada");
dw->setArchetype(Archetype::other);
dw->setGender(Gender::female);
dw->setAge(30);

// Coordinate frame: Y-up, centimetre, XYZ rotation order.
dw->setTranslationUnit(TranslationUnit::cm);
dw->setCoordinateSystem(CoordinateSystem::RightHand_YUp);
dw->setRotationUnit(RotationUnit::degrees);
dw->setRotationSequence(RotationSequence::XYZ);

// Six LOD levels: 0 (highest detail) ... 5 (lowest).
dw->setLODCount(6);
dw->setDBMaxLOD(5);

// Optional key-value metadata; overwrite or delete by key.
dw->setMetaData("rig_version", "2.4.1");
dw->setMetaData("obsolete_key", nullptr);  // deletes the entry

dw->setDBComplexity("Face");
dw->setDBName("MetaHumans");

Parameters

Name	Type	Description
`name` (setName)	`const char*`	required — null-terminated character name; the string is copied (allocation occurs).
`archetype`	`Archetype`	required — enum value describing the character archetype.
`gender`	`Gender`	required — enum value describing the character gender.
`age`	`std::uint16_t`	required — character age in years.
`key` (setMetaData)	`const char*`	required — unique null-terminated key; duplicate calls overwrite the previous value.
`value` (setMetaData)	`const char*`	required — null-terminated metadata value; pass `nullptr` to delete the key.
`unit` (setTranslationUnit)	`TranslationUnit`	required — spatial unit for translation values (e.g., centimetres, metres).
`unit` (setRotationUnit)	`RotationUnit`	required — angular unit for rotation values (e.g., degrees, radians).
`system`	`CoordinateSystem`	required — handedness and up-axis convention for the rig.
`rotationSequence`	`RotationSequence`	required — Euler rotation application order (e.g., XYZ).
`rotationSign`	`const RotationSign&`	required — sign convention for rotation axes.
`faceWindingOrder`	`FaceWindingOrder`	required — vertex winding order for face geometry.
`lodCount` (setLODCount)	`std::uint16_t`	required — total number of LOD levels; level 0 is highest detail.
`lod` (setDBMaxLOD)	`std::uint16_t`	required — maximum LOD index stored in the DNA data for this character.
`name` (setDBComplexity)	`const char*`	required — null-terminated name of the input control interface; string is copied.
`name` (setDBName)	`const char*`	required — null-terminated name of the originating database; string is copied.

Watch out for

Do not subclass DescriptorWriter directly — the class docstring states that implementors must inherit from Writer itself. Subclassing DescriptorWriter bypasses the full writer contract.
Passing nullptr as the value argument to setMetaData deletes the associated key rather than storing a null value. This is a deletion shortcut, not a no-op.
Every const char* name or value is copied internally, so the caller's buffer may be freed after the call — but each copy involves an allocation; avoid calling string setters in tight per-frame loops.

API Reference — dna/layers/DescriptorWriter

class DNAAPI DescriptorWriter : public HeaderWriter