Merge pull request #15275 from andreasplesch/patch-1

GLTFLoader: minor cubicspline interpolation optimization

examples/js/loaders/GLTFLoader.js

@@ -1046,11 +1046,11 @@ THREE.GLTFLoader = ( function () {
 		var offset1 = i1 * stride3;
 		var offset0 = offset1 - stride3;
 
-		var s0 = 2 * ppp - 3 * pp + 1;
-		var s1 = ppp - 2 * pp + p;
 		var s2 = - 2 * ppp + 3 * pp;
 		var s3 = ppp - pp;
-
+		var s0 = 1 - s2;
+		var s1 = s3 - pp + p;
+		
 		// Layout of keyframe output values for CUBICSPLINE animations:
 		//   [ inTangent_1, splineVertex_1, outTangent_1, inTangent_2, splineVertex_2, ... ]
 		for ( var i = 0; i !== stride; i ++ ) {