AnimationMixer: Move validate/optimize call, allow opt-out.

docs/api/animation/AnimationClip.html

@@ -46,6 +46,16 @@
 			array via [page:.resetDuration resetDuration].
 		</p>
 
+		<h3>[property:Boolean isOptimized]</h3>
+		<p>
+			Whether the clip has been optimized with .optimize().
+		</p>
+
+		<h3>[property:Boolean isValidated]</h3>
+		<p>
+			Whether the clip has been validated with .validate().
+		</p>
+
 		<h3>[property:String name]</h3>
 		<p>
 			A name for this clip. A certain clip can be searched via [page:.findByName findByName].
@@ -69,7 +79,8 @@
 		<h3>[method:AnimationClip optimize]()</h3>
 		<p>
 			Optimizes each track by removing equivalent sequential keys (which are common in morph target
-			sequences).
+			sequences). Called automatically by [page:AnimationMixer]'s clipAction() method. Calling this
+			method will set [page:.isValidated isValidated] to true, and additional calls will do nothing.
 		</p>
 
 		<h3>[method:null resetDuration]()</h3>
@@ -83,6 +94,13 @@
 			Trims all tracks to the clip's duration.
 		</p>
 
+		<h3>[method:AnimationClip validate]()</h3>
+		<p>
+			Performs minimal validation on each track in the clip. Called automatically by
+			[page:AnimationMixer]'s clipAction() method. Calling this method will set
+			[page:.isValidated isValidated] to true, and additional calls will do nothing.
+		</p>
+
 
 		<h2>Static Methods</h2>
 

docs/api/animation/AnimationMixer.html

@@ -55,6 +55,8 @@
 			from the mixer's default root. The first parameter can be either an [page:AnimationClip] object
 			or the name of an AnimationClip.<br /><br />
 
+			Automatically calls .validate() and .optimize() on the clip.<br /><br />
+
 			If an action fitting these parameters doesn't yet exist, it will be created by this method.<br /><br />
 
 			Note: Calling this method several times with the same parameters returns always the same clip

docs/api/animation/KeyframeTrack.html

@@ -204,8 +204,8 @@
 
 		<h3>[method:null optimize]()</h3>
 		<p>
-			Removes equivalent sequential keys, which are common in morph target sequences. Called
-			automatically by the constructor.
+			Removes equivalent sequential keys, which are common in morph target sequences. Calling this
+			method will set [page:.isOptimized isOptimized] to true, and additional calls will do nothing.
 		</p>
 
 		<h3>[method:null scale]()</h3>
@@ -236,7 +236,7 @@
 
 		<h3>[method:null validate]()</h3>
 		<p>
-			Performs minimal validation on the tracks. Called automatically by the constructor.<br /><br />
+			Performs minimal validation on the tracks.<br /><br />
 			This method logs errors to the console, if a track is empty, if the [page:.valueSize value size] is not valid, if an item
 			in the [page:.times times] or [page:.values values] array is not a valid number or if the items in the *times* array are out of order.
 		</p>

src/animation/AnimationClip.js

@@ -19,6 +19,9 @@ function AnimationClip( name, duration, tracks ) {
 	this.tracks = tracks;
 	this.duration = ( duration !== undefined ) ? duration : - 1;
 
+	this.isValidated = false;
+	this.isOptimized = false;
+
 	this.uuid = _Math.generateUUID();
 
 	// this means it should figure out its duration by scanning the tracks
@@ -28,8 +31,6 @@ function AnimationClip( name, duration, tracks ) {
 
 	}
 
-	this.optimize();
-
 }
 
 Object.assign( AnimationClip, {
@@ -341,8 +342,24 @@ Object.assign( AnimationClip.prototype, {
 
 	},
 
+	validate: function () {
+
+		if (this.isValidated) return this;
+
+		for ( var i = 0; i < this.tracks.length; i ++ ) {
+
+			this.tracks[ i ].validate();
+
+		}
+
+		return this;
+
+	},
+
 	optimize: function () {
 
+		if (this.isOptimized) return this;
+
 		for ( var i = 0; i < this.tracks.length; i ++ ) {
 
 			this.tracks[ i ].optimize();

src/animation/AnimationMixer.js

@@ -555,6 +555,9 @@ AnimationMixer.prototype = Object.assign( Object.create( EventDispatcher.prototy
 		// clip must be known when specified via string
 		if ( clipObject === null ) return null;
 
+		clipObject.validate();
+		clipObject.optimize();
+
 		// allocate all resources required to run it
 		var newAction = new AnimationAction( this, clipObject, optionalRoot );
 

src/animation/KeyframeTrack.js

@@ -36,9 +36,6 @@ function KeyframeTrack( name, times, values, interpolation ) {
 
 	this.setInterpolation( interpolation || this.DefaultInterpolation );
 
-	this.validate();
-	this.optimize();
-
 }
 
 // Static methods: