FBXLoader: add Periodic form for NURBS

examples/js/curves/NURBSCurve.js

@@ -13,11 +13,14 @@
  *	NURBS curve
  **************************************************************/
 
-THREE.NURBSCurve = function ( degree, knots /* array of reals */, controlPoints /* array of Vector(2|3|4) */ ) {
+THREE.NURBSCurve = function ( degree, knots /* array of reals */, controlPoints /* array of Vector(2|3|4) */, startKnot /* index in knots */, endKnot /* index in knots */ ) {
 
 	this.degree = degree;
 	this.knots = knots;
 	this.controlPoints = [];
+	// Used by periodic NURBS to remove hidden spans
+	this.startKnot = startKnot || 0;
+	this.endKnot = endKnot || ( this.knots.length - 1 );
 	for ( var i = 0; i < controlPoints.length; ++ i ) {
 
 		// ensure Vector4 for control points
@@ -35,7 +38,7 @@ THREE.NURBSCurve.prototype.constructor = THREE.NURBSCurve;
 
 THREE.NURBSCurve.prototype.getPoint = function ( t ) {
 
-	var u = this.knots[ 0 ] + t * ( this.knots[ this.knots.length - 1 ] - this.knots[ 0 ] ); // linear mapping t->u
+	var u = this.knots[ this.startKnot ] + t * ( this.knots[ this.endKnot ] - this.knots[ this.startKnot ] ); // linear mapping t->u
 
 	// following results in (wx, wy, wz, w) homogeneous point
 	var hpoint = THREE.NURBSUtils.calcBSplinePoint( this.degree, this.knots, this.controlPoints, u );

examples/js/loaders/FBXLoader.js

@@ -10,7 +10,7 @@
  *  - normal / uv
  *  - material (Multi-Material too)
  *  - textures (Must be in same directory)
- *  - nurbs
+ *  - nurbs (Open, Closed and Periodic forms)
  *
  *  No Support
  *  - morph
@@ -377,6 +377,7 @@
 
 			}
 
+			var degree = order - 1;
 			var knots = this.parseFloatList( nurbsInfo.subNodes.KnotVector.properties.a );
 
 			var controlPoints = [];
@@ -389,17 +390,30 @@
 
 			}
 
+			var startKnot, endKnot;
+
 			if ( nurbsInfo.properties.Form == "Closed" ) {
 
 				controlPoints.push( controlPoints[ 0 ] );
 
+			} else if ( nurbsInfo.properties.Form === 'Periodic' ) {
+
+				startKnot = degree;
+				endKnot = knots.length - 1 - startKnot;
+
+				for ( var i = 0; i < degree; ++ i ) {
+
+					controlPoints.push( controlPoints[ i ] );
+
+				}
+
 			}
 
-			var curve = new THREE.NURBSCurve( order - 1, knots, controlPoints );
+			var curve = new THREE.NURBSCurve( degree, knots, controlPoints, startKnot, endKnot );
 
 			// Pre-generate a geometry
 			var geometry = new THREE.Geometry();
-			geometry.vertices = curve.getPoints( controlPoints.length * 1.5 );
+			geometry.vertices = curve.getPoints( controlPoints.length * 7 );
 
 			var mesh = new THREE.Line( geometry );
 			// Store the THREE.NURBSCurve class so the user can recreate a new geometry with a different number of points

examples/js/loaders/FBXLoader2.js

@@ -12,6 +12,7 @@
  *  Animation
  * 	- Separated Animations based on stacks.
  * 	- Skeletal & Non-Skeletal Animations
+ *  NURBS (Open, Closed and Periodic forms)
  *
  * Needs Support:
  * 	Indexed Buffers
@@ -1010,15 +1011,7 @@
 
 						}
 
-						if ( geometryNode.properties.Form === 'Periodic' ) {
-
-							console.error( "FBXLoader: Currently no support for Periodic Nurbs Curves for geometry ID: " + geometryNode.id + ", using empty geometry buffer." );
-							return new THREE.BufferGeometry();
-
-							//TODO: Support Periodic NURBS curves.
-							//Info Link: https://knowledge.autodesk.com/support/maya/learn-explore/caas/CloudHelp/cloudhelp/2015/ENU/Maya/files/NURBS-overview-Periodic-closed-and-open-geometry-htm.html
-
-						}
+						var degree = order - 1;
 
 						var knots = parseFloatArray( geometryNode.subNodes.KnotVector.properties.a );
 						var controlPoints = [];
@@ -1030,14 +1023,27 @@
 
 						}
 
+						var startKnot, endKnot;
+
 						if ( geometryNode.properties.Form === 'Closed' ) {
 
 							controlPoints.push( controlPoints[ 0 ] );
 
+						} else if ( geometryNode.properties.Form === 'Periodic' ) {
+
+							startKnot = degree;
+							endKnot = knots.length - 1 - startKnot;
+
+							for ( var i = 0; i < degree; ++ i ) {
+
+								controlPoints.push( controlPoints[ i ] );
+
+							}
+
 						}
 
-						var curve = new THREE.NURBSCurve( order - 1, knots, controlPoints );
-						var vertices = curve.getPoints( controlPoints.length * 1.5 );
+						var curve = new THREE.NURBSCurve( degree, knots, controlPoints, startKnot, endKnot );
+						var vertices = curve.getPoints( controlPoints.length * 7 );
 
 						var vertexBuffer = [];
 						for ( var verticesIndex = 0, verticesLength = vertices.length; verticesIndex < verticesLength; ++ verticesIndex ) {