Fixed doc

src/Animations/babylon.animation.ts

@@ -456,6 +456,14 @@
             return Color3.Lerp(startValue, endValue, gradient);
         }
 
+        /**
+         * Defines the function to use to interpolate matrices
+         * @param startValue defines the start matrix
+         * @param endValue defines the end matrix
+         * @param gradient defines the gradient between both matrices 
+         * @param result defines an optional target matrix where to store the interpolation
+         * @returns the interpolated matrix
+         */
         public matrixInterpolateFunction(startValue: Matrix, endValue: Matrix, gradient: number, result?: Matrix): Matrix {
             if (Animation.AllowMatrixDecomposeForInterpolation) {
                 if (result) {