switch to relative morph targets

examples/js/loaders/FBXLoader.js

@@ -2058,10 +2058,12 @@ THREE.FBXLoader = ( function () {
 
 			if ( morphTargets.length === 0 ) return;
 
+			parentGeo.morphTargetsRelative = true;
+
 			parentGeo.morphAttributes.position = [];
 			// parentGeo.morphAttributes.normal = []; // not implemented
 
-			 var self = this;
+			var self = this;
 			morphTargets.forEach( function ( morphTarget ) {
 
 				morphTarget.rawTargets.forEach( function ( rawTarget ) {
@@ -2086,33 +2088,29 @@ THREE.FBXLoader = ( function () {
 		// Normal and position attributes only have data for the vertices that are affected by the morph
 		genMorphGeometry: function ( parentGeo, parentGeoNode, morphGeoNode, preTransform, name ) {
 
-			var morphGeo = new THREE.BufferGeometry();
-			if ( morphGeoNode.attrName ) morphGeo.name = morphGeoNode.attrName;
-
 			var vertexIndices = ( parentGeoNode.PolygonVertexIndex !== undefined ) ? parentGeoNode.PolygonVertexIndex.a : [];
 
-			// make a copy of the parent's vertex positions
-			var vertexPositions = ( parentGeoNode.Vertices !== undefined ) ? parentGeoNode.Vertices.a.slice() : [];
-
-			var morphPositions = ( morphGeoNode.Vertices !== undefined ) ? morphGeoNode.Vertices.a : [];
+			var morphPositionsSparse = ( morphGeoNode.Vertices !== undefined ) ? morphGeoNode.Vertices.a : [];
 			var indices = ( morphGeoNode.Indexes !== undefined ) ? morphGeoNode.Indexes.a : [];
 
+			var length = parentGeo.attributes.position.count * 3;
+			var morphPositions = new Float32Array( length );
+
 			for ( var i = 0; i < indices.length; i ++ ) {
 
 				var morphIndex = indices[ i ] * 3;
 
-				// FBX format uses blend shapes rather than morph targets. This can be converted
-				// by additively combining the blend shape positions with the original geometry's positions
-				vertexPositions[ morphIndex ] += morphPositions[ i * 3 ];
-				vertexPositions[ morphIndex + 1 ] += morphPositions[ i * 3 + 1 ];
-				vertexPositions[ morphIndex + 2 ] += morphPositions[ i * 3 + 2 ];
+				morphPositions[ morphIndex ] = morphPositionsSparse[ i * 3 ];
+				morphPositions[ morphIndex + 1 ] = morphPositionsSparse[ i * 3 + 1 ];
+				morphPositions[ morphIndex + 2 ] = morphPositionsSparse[ i * 3 + 2 ];
 
 			}
 
 			// TODO: add morph normal support
 			var morphGeoInfo = {
 				vertexIndices: vertexIndices,
-				vertexPositions: vertexPositions,
+				vertexPositions: morphPositions,
+
 			};
 
 			var morphBuffers = this.genBuffers( morphGeoInfo );

examples/jsm/loaders/FBXLoader.js

@@ -2106,10 +2106,12 @@ var FBXLoader = ( function () {
 
 			if ( morphTargets.length === 0 ) return;
 
+			parentGeo.morphTargetsRelative = true;
+
 			parentGeo.morphAttributes.position = [];
 			// parentGeo.morphAttributes.normal = []; // not implemented
 
-			 var self = this;
+			var self = this;
 			morphTargets.forEach( function ( morphTarget ) {
 
 				morphTarget.rawTargets.forEach( function ( rawTarget ) {
@@ -2134,33 +2136,29 @@ var FBXLoader = ( function () {
 		// Normal and position attributes only have data for the vertices that are affected by the morph
 		genMorphGeometry: function ( parentGeo, parentGeoNode, morphGeoNode, preTransform, name ) {
 
-			var morphGeo = new BufferGeometry();
-			if ( morphGeoNode.attrName ) morphGeo.name = morphGeoNode.attrName;
-
 			var vertexIndices = ( parentGeoNode.PolygonVertexIndex !== undefined ) ? parentGeoNode.PolygonVertexIndex.a : [];
 
-			// make a copy of the parent's vertex positions
-			var vertexPositions = ( parentGeoNode.Vertices !== undefined ) ? parentGeoNode.Vertices.a.slice() : [];
-
-			var morphPositions = ( morphGeoNode.Vertices !== undefined ) ? morphGeoNode.Vertices.a : [];
+			var morphPositionsSparse = ( morphGeoNode.Vertices !== undefined ) ? morphGeoNode.Vertices.a : [];
 			var indices = ( morphGeoNode.Indexes !== undefined ) ? morphGeoNode.Indexes.a : [];
 
+			var length = parentGeo.attributes.position.count * 3;
+			var morphPositions = new Float32Array( length );
+
 			for ( var i = 0; i < indices.length; i ++ ) {
 
 				var morphIndex = indices[ i ] * 3;
 
-				// FBX format uses blend shapes rather than morph targets. This can be converted
-				// by additively combining the blend shape positions with the original geometry's positions
-				vertexPositions[ morphIndex ] += morphPositions[ i * 3 ];
-				vertexPositions[ morphIndex + 1 ] += morphPositions[ i * 3 + 1 ];
-				vertexPositions[ morphIndex + 2 ] += morphPositions[ i * 3 + 2 ];
+				morphPositions[ morphIndex ] = morphPositionsSparse[ i * 3 ];
+				morphPositions[ morphIndex + 1 ] = morphPositionsSparse[ i * 3 + 1 ];
+				morphPositions[ morphIndex + 2 ] = morphPositionsSparse[ i * 3 + 2 ];
 
 			}
 
 			// TODO: add morph normal support
 			var morphGeoInfo = {
 				vertexIndices: vertexIndices,
-				vertexPositions: vertexPositions,
+				vertexPositions: morphPositions,
+
 			};
 
 			var morphBuffers = this.genBuffers( morphGeoInfo );