API Reference — dna/layers/BehaviorWriter

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class DNAAPI BehaviorWriter : public virtual DefinitionWriter

Write rig evaluation behavior data into a DNA asset — GUI-to-raw control mapping, PSD expressions, joint group matrices, blend shape channels, and animated maps. Do not subclass this directly; inherit from Writer instead.

When to use this

Use when constructing or modifying the behavioral layer of a DNA asset — populating evaluation data that drives how raw controls respond to GUI inputs, how joints are driven by PSD expressions, or how blend shapes and animated maps are activated per LOD. If you only need to read behavior data, use BehaviorReader instead.

Watch out for

• Implementors must inherit from Writer, not from BehaviorWriter directly. Subclassing BehaviorWriter directly bypasses lifecycle management provided by Writer.
• jointGroupIndex passed to any setJointGroup* method must be less than the value returned by getJointGroupCount. Joint group storage is implicitly resized when an index exceeds current capacity, but out-of-range indices still violate the documented precondition.
• The LOD values set via setBlendShapeChannelLODs are not interchangeable with the LOD indices set in DefinitionWriter::setBlendShapeNameIndices and DefinitionWriter::setLODBlendShapeMapping. Passing the wrong set silently produces incorrect blend shape evaluation at runtime.

Method groups

Group	Methods
GUI-to-raw mapping	setGUIToRawInputIndices, setGUIToRawOutputIndices, setGUIToRawFromValues, setGUIToRawToValues, setGUIToRawSlopeValues, setGUIToRawCutValues
PSD expressions	setPSDCount, setPSDRowIndices, setPSDColumnIndices, setPSDValues
Joint matrix dimensions	setJointRowCount, setJointColumnCount
Joint groups	clearJointGroups, deleteJointGroup, setJointGroupLODs, setJointGroupInputIndices, setJointGroupOutputIndices, setJointGroupValues, setJointGroupJointIndices
Blend shape channels	setBlendShapeChannelLODs, setBlendShapeChannelInputIndices, setBlendShapeChannelOutputIndices
Animated maps	setAnimatedMapLODs, setAnimatedMapInputIndices, setAnimatedMapOutputIndices, setAnimatedMapFromValues, setAnimatedMapToValues, setAnimatedMapSlopeValues, setAnimatedMapCutValues

Example

// Populate GUI-to-raw mapping
writer->setGUIToRawInputIndices(guiInputIdx.data(), static_cast<uint16_t>(guiInputIdx.size()));
writer->setGUIToRawOutputIndices(rawOutputIdx.data(), static_cast<uint16_t>(rawOutputIdx.size()));
writer->setGUIToRawFromValues(fromVals.data(), static_cast<uint16_t>(fromVals.size()));
writer->setGUIToRawSlopeValues(slopes.data(), static_cast<uint16_t>(slopes.size()));
writer->setGUIToRawCutValues(cuts.data(), static_cast<uint16_t>(cuts.size()));

// Populate PSD expressions
writer->setPSDCount(static_cast<uint16_t>(psdCount));
writer->setPSDRowIndices(psdRows.data(), static_cast<uint16_t>(psdRows.size()));
writer->setPSDColumnIndices(psdCols.data(), static_cast<uint16_t>(psdCols.size()));
writer->setPSDValues(psdWeights.data(), static_cast<uint16_t>(psdWeights.size()));