HumanoidRetargeter/Core/Formats/Gltf/GltfModelDmxWriter.Morphs.cs
Writer and reader helpers for glTF morph targets in DMX output. ReadMorphs parses glTF morph target POSITION deltas into per-vertex Vector3 arrays, applying transforms and unit conversion. WriteMorphDeltas emits DMX deltaStates and associated arrays for nonzero deltas. WriteMorphControls writes combination operator controls and default weights for all morph names across mesh parts.
File Access
using System;
using System.Collections.Generic;
using System.Numerics;
using System.Text.Json;
using HumanoidRetargeter.Core.Formats.Fbx;
namespace HumanoidRetargeter.Core.Formats.Gltf;
using Vector3 = System.Numerics.Vector3;
public static partial class GltfModelDmxWriter
{
private static Dictionary<string, Vector3[]> ReadMorphs( GltfDocument document, JsonElement mesh,
JsonElement primitive, Matrix4x4[] transforms )
{
var result = new Dictionary<string, Vector3[]>( StringComparer.Ordinal );
if ( !primitive.TryGetProperty( "targets", out var targets ) )
return result;
var names = mesh.TryGetProperty( "extras", out var extras ) && extras.TryGetProperty( "targetNames", out var targetNames )
? targetNames : default;
var index = 0;
foreach ( var target in targets.EnumerateArray() )
{
var name = names.ValueKind == JsonValueKind.Array && index < names.GetArrayLength()
? names[ index ].GetString() : $"morph_{index}";
index++;
if ( !target.TryGetProperty( "POSITION", out var property ) )
continue;
var accessor = new Accessor( document, property.GetInt32(), 3 );
RequireCount( accessor, transforms.Length, "morph POSITION" );
var deltas = new Vector3[ transforms.Length ];
for ( var i = 0; i < deltas.Length; i++ )
{
var delta = new Vector3( accessor.Float( i, 0 ), accessor.Float( i, 1 ), accessor.Float( i, 2 ) );
deltas[ i ] = Vector3.TransformNormal( delta, transforms[ i ] ) * MetersToCentimeters;
}
if ( string.IsNullOrWhiteSpace( name ) || !result.TryAdd( name, deltas ) )
throw new FormatException( "glTF morph target names must be nonempty and unique." );
}
return result;
}
private static void WriteMorphDeltas( Kv2Writer writer, MeshPart part )
{
if ( part.Morphs.Count == 0 )
return;
writer.BeginArray( "deltaStates" );
var morphIndex = 0;
foreach ( var (name, deltas) in part.Morphs )
{
writer.BeginArrayElement( "DmeVertexDeltaData" );
writer.Attr( "name", "string", HumanoidRetargeter.Core.Formats.Dmx.DmxWriter.MorphName( name ) );
writer.BeginArray( "vertexFormat", "string_array" );
writer.Value( "position$0", true );
writer.EndArray();
var indices = Enumerable.Range( 0, deltas.Length ).Where( i => deltas[ i ].LengthSquared() > 1e-16f ).ToArray();
WriteVectors( writer, "position$0", "vector3_array", indices.Select( i => deltas[ i ] ).ToArray(), Vec );
WriteScalars( writer, "position$0Indices", "int_array", indices, i => i.ToString( System.Globalization.CultureInfo.InvariantCulture ) );
writer.EndArrayElement( ++morphIndex == part.Morphs.Count );
}
writer.EndArray();
foreach ( var property in new[] { "deltaStateWeights", "deltaStateWeightsLagged" } )
{
writer.BeginArray( property, "vector2_array" );
for ( var i = 0; i < part.Morphs.Count; i++ )
writer.Value( "0 0", i == part.Morphs.Count - 1 );
writer.EndArray();
}
}
private static void WriteMorphControls( Kv2Writer writer, IReadOnlyList<MeshPart> parts, string[] meshIds )
{
var names = parts.SelectMany( part => part.Morphs.Keys ).Distinct( StringComparer.Ordinal )
.Select( HumanoidRetargeter.Core.Formats.Dmx.DmxWriter.MorphName ).ToArray();
if ( names.Length == 0 )
return;
writer.BeginInline( "combinationOperator", "DmeCombinationOperator" );
writer.Attr( "name", "string", "combinationOperator" );
writer.BeginArray( "controls" );
for ( var i = 0; i < names.Length; i++ )
{
writer.BeginArrayElement( "DmeCombinationInputControl" );
writer.Attr( "name", "string", names[ i ] );
writer.Attr( "stereo", "bool", "0" );
writer.Attr( "eyelid", "bool", "0" );
writer.BeginArray( "rawControlNames", "string_array" );
writer.Value( names[ i ], true );
writer.EndArray();
writer.BeginArray( "wrinkleScales", "float_array" );
writer.Value( "0", true );
writer.EndArray();
writer.EndArrayElement( i == names.Length - 1 );
}
writer.EndArray();
foreach ( var property in new[] { "controlValues", "controlValuesLagged" } )
{
writer.BeginArray( property, "vector3_array" );
for ( var i = 0; i < names.Length; i++ )
writer.Value( "0 0.5 0.5", i == names.Length - 1 );
writer.EndArray();
}
WriteRefs( writer, "targets", meshIds );
writer.EndInline();
}
}