diff --git a/jme3-core/src/main/java/com/jme3/anim/AnimClip.java b/jme3-core/src/main/java/com/jme3/anim/AnimClip.java
index 31cf5b1055..9758c2d718 100644
--- a/jme3-core/src/main/java/com/jme3/anim/AnimClip.java
+++ b/jme3-core/src/main/java/com/jme3/anim/AnimClip.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2020 jMonkeyEngine
+ * Copyright (c) 2009-2021 jMonkeyEngine
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -38,6 +38,8 @@
 import java.io.IOException;
 
 /**
+ * A named set of animation tracks that can be played in synchrony.
+ *
  * Created by Nehon on 20/12/2017.
  */
 public class AnimClip implements JmeCloneable, Savable {
@@ -47,13 +49,27 @@ public class AnimClip implements JmeCloneable, Savable {
 
     private AnimTrack[] tracks;
 
+    /**
+     * No-argument constructor needed by SavableClassUtil.
+     */
     protected AnimClip() {
     }
 
+    /**
+     * Instantiate a zero-length clip with the specified name.
+     *
+     * @param name desired name for the new clip
+     */
     public AnimClip(String name) {
         this.name = name;
     }
 
+    /**
+     * Replace all tracks in this clip. This method may increase the clip's
+     * length, but it will never reduce it.
+     *
+     * @param tracks the tracks to use (alias created)
+     */
     public void setTracks(AnimTrack[] tracks) {
         this.tracks = tracks;
         for (AnimTrack track : tracks) {
@@ -63,20 +79,38 @@ public void setTracks(AnimTrack[] tracks) {
         }
     }
 
+    /**
+     * Determine the name of this clip.
+     *
+     * @return the name
+     */
     public String getName() {
         return name;
     }
 
-
+    /**
+     * Determine the duration of this clip.
+     *
+     * @return the duration (in seconds)
+     */
     public double getLength() {
         return length;
     }
 
-
+    /**
+     * Access all the tracks in this clip.
+     *
+     * @return the pre-existing array
+     */
     public AnimTrack[] getTracks() {
         return tracks;
     }
 
+    /**
+     * Create a shallow clone for the JME cloner.
+     *
+     * @return a new instance
+     */
     @Override
     public Object jmeClone() {
         try {
@@ -86,6 +120,15 @@ public Object jmeClone() {
         }
     }
 
+    /**
+     * Callback from {@link com.jme3.util.clone.Cloner} to convert this
+     * shallow-cloned clip into a deep-cloned one, using the specified Cloner
+     * and original to resolve copied fields.
+     *
+     * @param cloner the Cloner that's cloning this clip (not null)
+     * @param original the instance from which this clip was shallow-cloned (not
+     * null, unaffected)
+     */
     @Override
     public void cloneFields(Cloner cloner, Object original) {
         AnimTrack[] newTracks = new AnimTrack[tracks.length];
@@ -95,11 +138,23 @@ public void cloneFields(Cloner cloner, Object original) {
         this.tracks = newTracks;
     }
 
+    /**
+     * Represent this clip as a String.
+     *
+     * @return a descriptive string of text (not null, not empty)
+     */
     @Override
     public String toString() {
         return "Clip " + name + ", " + length + 's';
     }
 
+    /**
+     * Serialize this clip to the specified exporter, for example when saving to
+     * a J3O file.
+     *
+     * @param ex the exporter to write to (not null)
+     * @throws IOException from the exporter
+     */
     @Override
     public void write(JmeExporter ex) throws IOException {
         OutputCapsule oc = ex.getCapsule(this);
@@ -108,6 +163,13 @@ public void write(JmeExporter ex) throws IOException {
 
     }
 
+    /**
+     * De-serialize this clip from the specified importer, for example when
+     * loading from a J3O file.
+     *
+     * @param im the importer to read from (not null)
+     * @throws IOException from the importer
+     */
     @Override
     public void read(JmeImporter im) throws IOException {
         InputCapsule ic = im.getCapsule(this);
diff --git a/jme3-core/src/main/java/com/jme3/anim/AnimComposer.java b/jme3-core/src/main/java/com/jme3/anim/AnimComposer.java
index 7c404e535b..c290f01073 100644
--- a/jme3-core/src/main/java/com/jme3/anim/AnimComposer.java
+++ b/jme3-core/src/main/java/com/jme3/anim/AnimComposer.java
@@ -65,6 +65,9 @@ public class AnimComposer extends AbstractControl {
     private float globalSpeed = 1f;
     private Map<String, Layer> layers = new LinkedHashMap<>();
 
+    /**
+     * Instantiate a composer with a single layer, no actions, and no clips.
+     */
     public AnimComposer() {
         layers.put(DEFAULT_LAYER, new Layer(this));
     }
@@ -314,6 +317,12 @@ public Action removeAction(String name) {
         return actions.remove(name);
     }
 
+    /**
+     * Add a layer to this composer.
+     *
+     * @param name the desired name for the new layer
+     * @param mask the desired mask for the new layer (alias created)
+     */
     public void makeLayer(String name, AnimationMask mask) {
         Layer l = new Layer(this);
         l.mask = mask;
@@ -363,6 +372,9 @@ public BlendAction actionBlended(String name, BlendSpace blendSpace, String... c
         return action;
     }
 
+    /**
+     * Reset all layers to t=0 with no current action.
+     */
     public void reset() {
         for (Layer layer : layers.values()) {
             layer.currentAction = null;
@@ -391,6 +403,11 @@ public Set<String> getAnimClipsNames() {
         return Collections.unmodifiableSet(animClipMap.keySet());
     }
 
+    /**
+     * used internally
+     *
+     * @param tpf time per frame (in seconds)
+     */
     @Override
     protected void controlUpdate(float tpf) {
         for (Layer layer : layers.values()) {
@@ -410,19 +427,40 @@ protected void controlUpdate(float tpf) {
         }
     }
 
+    /**
+     * used internally
+     *
+     * @param rm the RenderManager rendering the controlled Spatial (not null)
+     * @param vp the ViewPort being rendered (not null)
+     */
     @Override
     protected void controlRender(RenderManager rm, ViewPort vp) {
 
     }
 
+    /**
+     * Determine the global speed applied to all layers.
+     *
+     * @return the speed factor (1=normal speed)
+     */
     public float getGlobalSpeed() {
         return globalSpeed;
     }
 
+    /**
+     * Alter the global speed applied to all layers.
+     *
+     * @param globalSpeed the desired speed factor (1=normal speed, default=1)
+     */
     public void setGlobalSpeed(float globalSpeed) {
         this.globalSpeed = globalSpeed;
     }
 
+    /**
+     * Create a shallow clone for the JME cloner.
+     *
+     * @return a new instance
+     */
     @Override
     public Object jmeClone() {
         try {
@@ -433,6 +471,15 @@ public Object jmeClone() {
         }
     }
 
+    /**
+     * Callback from {@link com.jme3.util.clone.Cloner} to convert this
+     * shallow-cloned composer into a deep-cloned one, using the specified
+     * Cloner and original to resolve copied fields.
+     *
+     * @param cloner the Cloner that's cloning this composer (not null)
+     * @param original the instance from which this composer was shallow-cloned
+     * (not null, unaffected)
+     */
     @Override
     public void cloneFields(Cloner cloner, Object original) {
         super.cloneFields(cloner, original);
@@ -456,6 +503,13 @@ public void cloneFields(Cloner cloner, Object original) {
 
     }
 
+    /**
+     * De-serialize this composer from the specified importer, for example when
+     * loading from a J3O file.
+     *
+     * @param im the importer to use (not null)
+     * @throws IOException from the importer
+     */
     @Override
     @SuppressWarnings("unchecked")
     public void read(JmeImporter im) throws IOException {
@@ -465,6 +519,13 @@ public void read(JmeImporter im) throws IOException {
         globalSpeed = ic.readFloat("globalSpeed", 1f);
     }
 
+    /**
+     * Serialize this composer to the specified exporter, for example when
+     * saving to a J3O file.
+     *
+     * @param ex the exporter to use (not null)
+     * @throws IOException from the exporter
+     */
     @Override
     public void write(JmeExporter ex) throws IOException {
         super.write(ex);
diff --git a/jme3-core/src/main/java/com/jme3/anim/AnimTrack.java b/jme3-core/src/main/java/com/jme3/anim/AnimTrack.java
index 45b54cf7f9..4c00902016 100644
--- a/jme3-core/src/main/java/com/jme3/anim/AnimTrack.java
+++ b/jme3-core/src/main/java/com/jme3/anim/AnimTrack.java
@@ -3,10 +3,25 @@
 import com.jme3.export.Savable;
 import com.jme3.util.clone.JmeCloneable;
 
+/**
+ * Interface to derive animation data from a track.
+ *
+ * @param <T> the type of data that's being animated, such as Transform
+ */
 public interface AnimTrack<T> extends Savable, JmeCloneable {
 
+    /**
+     * Determine the track value for the specified time.
+     *
+     * @param time the track time (in seconds)
+     * @param store storage for the value (not null, modified)
+     */
     public void getDataAtTime(double time, T store);
-    public double getLength();
-
 
+    /**
+     * Determine the duration of the track.
+     *
+     * @return the duration (in seconds, &ge;0)
+     */
+    public double getLength();
 }
diff --git a/jme3-core/src/main/java/com/jme3/anim/AnimationMask.java b/jme3-core/src/main/java/com/jme3/anim/AnimationMask.java
index 80036776c3..2d6b775a4c 100644
--- a/jme3-core/src/main/java/com/jme3/anim/AnimationMask.java
+++ b/jme3-core/src/main/java/com/jme3/anim/AnimationMask.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2020 jMonkeyEngine
+ * Copyright (c) 2009-2021 jMonkeyEngine
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -38,6 +38,12 @@
  */
 public interface AnimationMask {
 
+    /**
+     * Test whether the animation should applied to the specified element.
+     *
+     * @param target the target element
+     * @return true if animation should be applied, otherwise false
+     */
     boolean contains(Object target);
 
 }
diff --git a/jme3-core/src/main/java/com/jme3/anim/Armature.java b/jme3-core/src/main/java/com/jme3/anim/Armature.java
index 8ae16cf485..807db3acae 100644
--- a/jme3-core/src/main/java/com/jme3/anim/Armature.java
+++ b/jme3-core/src/main/java/com/jme3/anim/Armature.java
@@ -145,6 +145,11 @@ public Joint[] getRoots() {
         return rootJoints;
     }
 
+    /**
+     * Access all joints in this Armature.
+     *
+     * @return a new list of pre-existing joints
+     */
     public List<Joint> getJointList() {
         return Arrays.asList(jointList);
     }
@@ -290,7 +295,13 @@ public void cloneFields(Cloner cloner, Object original) {
         }
     }
 
-
+    /**
+     * De-serialize this Armature from the specified importer, for example when
+     * loading from a J3O file.
+     *
+     * @param im the importer to read from (not null)
+     * @throws IOException from the importer
+     */
     @Override
     @SuppressWarnings("unchecked")
     public void read(JmeImporter im) throws IOException {
@@ -324,6 +335,13 @@ public void read(JmeImporter im) throws IOException {
         applyInitialPose();
     }
 
+    /**
+     * Serialize this Armature to the specified exporter, for example when
+     * saving to a J3O file.
+     *
+     * @param ex the exporter to write to (not null)
+     * @throws IOException from the exporter
+     */
     @Override
     public void write(JmeExporter ex) throws IOException {
         OutputCapsule output = ex.getCapsule(this);
diff --git a/jme3-core/src/main/java/com/jme3/anim/ArmatureMask.java b/jme3-core/src/main/java/com/jme3/anim/ArmatureMask.java
index a7d5d32f09..3aa2342f28 100644
--- a/jme3-core/src/main/java/com/jme3/anim/ArmatureMask.java
+++ b/jme3-core/src/main/java/com/jme3/anim/ArmatureMask.java
@@ -2,6 +2,9 @@
 
 import java.util.BitSet;
 
+/**
+ * An AnimationMask to select joints from a single Armature.
+ */
 public class ArmatureMask implements AnimationMask {
 
     final private BitSet affectedJoints = new BitSet();
@@ -62,12 +65,27 @@ public boolean contains(Object target) {
         return affectedJoints.get(((Joint) target).getId());
     }
 
+    /**
+     * Create an ArmatureMask that selects the named Joint and all its
+     * descendants.
+     *
+     * @param armature the Armature containing the joints (not null)
+     * @param fromJoint the name of the ancestor joint
+     * @return a new mask
+     */
     public static ArmatureMask createMask(Armature armature, String fromJoint) {
         ArmatureMask mask = new ArmatureMask();
         mask.addFromJoint(armature, fromJoint);
         return mask;
     }
 
+    /**
+     * Create an ArmatureMask that selects the named joints.
+     *
+     * @param armature the Armature containing the joints (not null)
+     * @param joints the names of the joints to be included
+     * @return a new mask
+     */
     public static ArmatureMask createMask(Armature armature, String... joints) {
         ArmatureMask mask = new ArmatureMask();
         mask.addBones(armature, joints);
diff --git a/jme3-core/src/main/java/com/jme3/anim/Joint.java b/jme3-core/src/main/java/com/jme3/anim/Joint.java
index eefa4797f3..434931d337 100644
--- a/jme3-core/src/main/java/com/jme3/anim/Joint.java
+++ b/jme3-core/src/main/java/com/jme3/anim/Joint.java
@@ -88,10 +88,17 @@ public class Joint implements Savable, JmeCloneable, HasLocalTransform {
      */
     private Matrix4f inverseModelBindMatrix = new Matrix4f();
 
-
+    /**
+     * Instantiate a nameless Joint.
+     */
     public Joint() {
     }
 
+    /**
+     * Instantiate a Joint with the specified name.
+     *
+     * @param name the desired name
+     */
     public Joint(String name) {
         this.name = name;
     }
@@ -206,64 +213,139 @@ protected void applyInitialPose() {
         }
     }
 
+    /**
+     * Access the accumulated model transform.
+     *
+     * @return the pre-existing instance
+     */
     protected JointModelTransform getJointModelTransform() {
         return jointModelTransform;
     }
 
+    /**
+     * Replace the accumulated model transform.
+     *
+     * @param jointModelTransform the transform to use (alias created)
+     */
     protected void setJointModelTransform(JointModelTransform jointModelTransform) {
         this.jointModelTransform = jointModelTransform;
     }
 
+    /**
+     * Access the local translation vector.
+     *
+     * @return the pre-existing vector
+     */
     public Vector3f getLocalTranslation() {
         return localTransform.getTranslation();
     }
 
+    /**
+     * Access the local rotation.
+     *
+     * @return the pre-existing Quaternion
+     */
     public Quaternion getLocalRotation() {
         return localTransform.getRotation();
     }
 
+    /**
+     * Access the local scale vector.
+     *
+     * @return the pre-existing vector
+     */
     public Vector3f getLocalScale() {
         return localTransform.getScale();
     }
 
+    /**
+     * Alter the local translation vector.
+     *
+     * @param translation the desired offset vector (not null, unaffected)
+     */
     public void setLocalTranslation(Vector3f translation) {
         localTransform.setTranslation(translation);
     }
 
+    /**
+     * Alter the local rotation.
+     *
+     * @param rotation the desired rotation (not null, unaffected)
+     */
     public void setLocalRotation(Quaternion rotation) {
         localTransform.setRotation(rotation);
     }
 
+    /**
+     * Alter the local scale vector.
+     *
+     * @param scale the desired scale factors (not null, unaffected)
+     */
     public void setLocalScale(Vector3f scale) {
         localTransform.setScale(scale);
     }
 
+    /**
+     * Add the specified Joint as a child.
+     *
+     * @param child the Joint to add (not null, modified)
+     */
     public void addChild(Joint child) {
         children.add(child);
         child.parent = this;
     }
 
+    /**
+     * Alter the name.
+     *
+     * @param name the desired name
+     */
     public void setName(String name) {
         this.name = name;
     }
 
+    /**
+     * Alter the local transform.
+     *
+     * @param localTransform the desired Transform (not null, unaffected)
+     */
     @Override
     public void setLocalTransform(Transform localTransform) {
         this.localTransform.set(localTransform);
     }
 
+    /**
+     * Replace the inverse model bind matrix.
+     *
+     * @param inverseModelBindMatrix the matrix to use (alias created)
+     */
     public void setInverseModelBindMatrix(Matrix4f inverseModelBindMatrix) {
         this.inverseModelBindMatrix = inverseModelBindMatrix;
     }
 
+    /**
+     * Determine the name.
+     *
+     * @return the name
+     */
     public String getName() {
         return name;
     }
 
+    /**
+     * Access the parent joint.
+     *
+     * @return the pre-existing instance, or null if this is a root joint
+     */
     public Joint getParent() {
         return parent;
     }
 
+    /**
+     * Access the list of child joints.
+     *
+     * @return the pre-existing list
+     */
     public List<Joint> getChildren() {
         return children;
     }
@@ -300,31 +382,66 @@ Node getAttachmentsNode(int jointIndex, SafeArrayList<Geometry> targets) {
         return attachedNode;
     }
 
+    /**
+     * Access the initial transform.
+     *
+     * @return the pre-existing instance
+     */
     public Transform getInitialTransform() {
         return initialTransform;
     }
 
+    /**
+     * Access the local transform.
+     *
+     * @return the pre-existing instance
+     */
     @Override
     public Transform getLocalTransform() {
         return localTransform;
     }
 
+    /**
+     * Determine the model transform.
+     *
+     * @return a shared instance
+     */
     public Transform getModelTransform() {
         return jointModelTransform.getModelTransform();
     }
 
+    /**
+     * Determine the inverse model bind matrix.
+     *
+     * @return the pre-existing instance
+     */
     public Matrix4f getInverseModelBindMatrix() {
         return inverseModelBindMatrix;
     }
 
+    /**
+     * Determine this joint's index in the Armature that contains it.
+     *
+     * @return an index (&ge;0)
+     */
     public int getId() {
         return id;
     }
 
+    /**
+     * Alter this joint's index in the Armature that contains it.
+     *
+     * @param id the desired index (&ge;0)
+     */
     public void setId(int id) {
         this.id = id;
     }
 
+    /**
+     * Create a shallow clone for the JME cloner.
+     *
+     * @return a new instance
+     */
     @Override
     public Object jmeClone() {
         try {
@@ -335,6 +452,15 @@ public Object jmeClone() {
         }
     }
 
+    /**
+     * Callback from {@link com.jme3.util.clone.Cloner} to convert this
+     * shallow-cloned Joint into a deep-cloned one, using the specified Cloner
+     * and original to resolve copied fields.
+     *
+     * @param cloner the Cloner that's cloning this Joint (not null)
+     * @param original the instance from which this Joint was shallow-cloned
+     * (not null, unaffected)
+     */
     @Override
     public void cloneFields(Cloner cloner, Object original) {
         this.children = cloner.clone(children);
@@ -346,7 +472,13 @@ public void cloneFields(Cloner cloner, Object original) {
         this.inverseModelBindMatrix = cloner.clone(inverseModelBindMatrix);
     }
 
-
+    /**
+     * De-serialize this Joint from the specified importer, for example when
+     * loading from a J3O file.
+     *
+     * @param im the importer to use (not null)
+     * @throws IOException from the importer
+     */
     @Override
     @SuppressWarnings("unchecked")
     public void read(JmeImporter im) throws IOException {
@@ -364,6 +496,13 @@ public void read(JmeImporter im) throws IOException {
         }
     }
 
+    /**
+     * Serialize this Joint to the specified exporter, for example when saving
+     * to a J3O file.
+     *
+     * @param ex the exporter to write to (not null)
+     * @throws IOException from the exporter
+     */
     @Override
     @SuppressWarnings("unchecked")
     public void write(JmeExporter ex) throws IOException {
diff --git a/jme3-core/src/main/java/com/jme3/anim/MatrixJointModelTransform.java b/jme3-core/src/main/java/com/jme3/anim/MatrixJointModelTransform.java
index acbb4a9a6b..a87fbc0f74 100644
--- a/jme3-core/src/main/java/com/jme3/anim/MatrixJointModelTransform.java
+++ b/jme3-core/src/main/java/com/jme3/anim/MatrixJointModelTransform.java
@@ -36,6 +36,11 @@ public void applyBindPose(Transform localTransform, Matrix4f inverseModelBindMat
         localTransform.fromTransformMatrix(modelTransformMatrix);
     }
 
+    /**
+     * Access the model transform.
+     *
+     * @return the pre-existing instance 
+     */
     public Matrix4f getModelTransformMatrix() {
         return modelTransformMatrix;
     }
diff --git a/jme3-core/src/main/java/com/jme3/anim/MorphControl.java b/jme3-core/src/main/java/com/jme3/anim/MorphControl.java
index 2299e29244..401f4172ba 100644
--- a/jme3-core/src/main/java/com/jme3/anim/MorphControl.java
+++ b/jme3-core/src/main/java/com/jme3/anim/MorphControl.java
@@ -353,10 +353,22 @@ private int getRemainingBuffers(Mesh mesh, Renderer renderer) {
         return renderer.getLimits().get(Limits.VertexAttributes) - nbUsedBuffers;
     }
 
+    /**
+     * Alter whether this Control approximates tangents.
+     *
+     * @param approximateTangents true to approximate tangents, false to get
+     * them from a VertexBuffer
+     */
     public void setApproximateTangents(boolean approximateTangents) {
         this.approximateTangents = approximateTangents;
     }
 
+    /**
+     * Test whether this Control approximates tangents.
+     *
+     * @return true if approximating tangents, false if getting them from a
+     * VertexBuffer
+     */
     public boolean isApproximateTangents() {
         return approximateTangents;
     }
diff --git a/jme3-core/src/main/java/com/jme3/anim/MorphTrack.java b/jme3-core/src/main/java/com/jme3/anim/MorphTrack.java
index 0cbeed7deb..adf1056e76 100644
--- a/jme3-core/src/main/java/com/jme3/anim/MorphTrack.java
+++ b/jme3-core/src/main/java/com/jme3/anim/MorphTrack.java
@@ -174,18 +174,40 @@ public void getDataAtTime(double t, float[] store) {
         interpolator.interpolateWeights(blend, startFrame, weights, nbMorphTargets, store);
     }
 
+    /**
+     * Replace the FrameInterpolator.
+     *
+     * @param interpolator the interpolator to use (alias created)
+     */
     public void setFrameInterpolator(FrameInterpolator interpolator) {
         this.interpolator = interpolator;
     }
 
+    /**
+     * Access the target geometry.
+     *
+     * @return the pre-existing instance
+     */
     public Geometry getTarget() {
         return target;
     }
 
+    /**
+     * Replace the target geometry.
+     *
+     * @param target the Geometry to use as the target (alias created)
+     */
     public void setTarget(Geometry target) {
         this.target = target;
     }
 
+    /**
+     * Serialize this track to the specified exporter, for example when saving
+     * to a J3O file.
+     *
+     * @param ex the exporter to write to (not null)
+     * @throws IOException from the exporter
+     */
     @Override
     public void write(JmeExporter ex) throws IOException {
         OutputCapsule oc = ex.getCapsule(this);
@@ -195,6 +217,13 @@ public void write(JmeExporter ex) throws IOException {
         oc.write(nbMorphTargets, "nbMorphTargets", 0);
     }
 
+    /**
+     * De-serialize this track from the specified importer, for example when
+     * loading from a J3O file.
+     *
+     * @param im the importer to use (not null)
+     * @throws IOException from the importer
+     */
     @Override
     public void read(JmeImporter im) throws IOException {
         InputCapsule ic = im.getCapsule(this);
diff --git a/jme3-core/src/main/java/com/jme3/anim/SkinningControl.java b/jme3-core/src/main/java/com/jme3/anim/SkinningControl.java
index fd312a5d8f..3f2ad3e2a2 100644
--- a/jme3-core/src/main/java/com/jme3/anim/SkinningControl.java
+++ b/jme3-core/src/main/java/com/jme3/anim/SkinningControl.java
@@ -701,6 +701,13 @@ private void applySkinningTangents(Mesh mesh, Matrix4f[] offsetMatrices, VertexB
         tb.updateData(ftb);
     }
 
+    /**
+     * Serialize this Control to the specified exporter, for example when saving
+     * to a J3O file.
+     *
+     * @param ex the exporter to write to (not null)
+     * @throws IOException from the exporter
+     */
     @Override
     public void write(JmeExporter ex) throws IOException {
         super.write(ex);
@@ -711,6 +718,13 @@ public void write(JmeExporter ex) throws IOException {
         oc.write(jointMatricesParam, "boneMatricesParam", null);
     }
 
+    /**
+     * De-serialize this Control from the specified importer, for example when
+     * loading from a J3O file.
+     *
+     * @param im the importer to read from (not null)
+     * @throws IOException from the importer
+     */
     @Override
     public void read(JmeImporter im) throws IOException {
         super.read(im);
diff --git a/jme3-core/src/main/java/com/jme3/anim/TransformTrack.java b/jme3-core/src/main/java/com/jme3/anim/TransformTrack.java
index c9830ef6b5..7df1b515a6 100644
--- a/jme3-core/src/main/java/com/jme3/anim/TransformTrack.java
+++ b/jme3-core/src/main/java/com/jme3/anim/TransformTrack.java
@@ -268,18 +268,41 @@ public void getDataAtTime(double t, Transform transform) {
         }
     }
 
+    /**
+     * Replace the frame interpolator.
+     *
+     * @param interpolator the interpolator to use (alias created)
+     */
     public void setFrameInterpolator(FrameInterpolator interpolator) {
         this.interpolator = interpolator;
     }
 
+    /**
+     * Access the target affected by this track, which might be a Joint or a
+     * Spatial.
+     *
+     * @return the pre-existing instance
+     */
     public HasLocalTransform getTarget() {
         return target;
     }
 
+    /**
+     * Replace the target of this track, which might be a Joint or a Spatial.
+     *
+     * @param target the target to use (alias created)
+     */
     public void setTarget(HasLocalTransform target) {
         this.target = target;
     }
 
+    /**
+     * Serialize this track to the specified exporter, for example when
+     * saving to a J3O file.
+     *
+     * @param ex the exporter to write to (not null)
+     * @throws IOException from the exporter
+     */
     @Override
     public void write(JmeExporter ex) throws IOException {
         OutputCapsule oc = ex.getCapsule(this);
@@ -290,6 +313,13 @@ public void write(JmeExporter ex) throws IOException {
         oc.write(target, "target", null);
     }
 
+    /**
+     * De-serialize this track from the specified importer, for example when
+     * loading from a J3O file.
+     *
+     * @param im the importer to read from (not null)
+     * @throws IOException from the importer
+     */
     @Override
     public void read(JmeImporter im) throws IOException {
         InputCapsule ic = im.getCapsule(this);
diff --git a/jme3-core/src/main/java/com/jme3/anim/util/JointModelTransform.java b/jme3-core/src/main/java/com/jme3/anim/util/JointModelTransform.java
index c73c033169..837c50ca2e 100644
--- a/jme3-core/src/main/java/com/jme3/anim/util/JointModelTransform.java
+++ b/jme3-core/src/main/java/com/jme3/anim/util/JointModelTransform.java
@@ -10,11 +10,37 @@
  */
 public interface JointModelTransform {
 
+    /**
+     * Update the joint's transform in model space.
+     *
+     * @param localTransform the joint's local transform (not null, unaffected)
+     * @param parent the joint's parent, or null for a root joint
+     */
     void updateModelTransform(Transform localTransform, Joint parent);
 
+    /**
+     * Determine the joint's skinning transform.
+     *
+     * @param outTransform storage for the result (modified if not null)
+     * @param inverseModelBindMatrix the joint's inverse model bind matrix (not
+     * null, unaffected)
+     */
     void getOffsetTransform(Matrix4f outTransform, Matrix4f inverseModelBindMatrix);
 
+    /**
+     * Configure joint's local transform for bind pose.
+     *
+     * @param localTransform the joint's local transform (not null, unaffected)
+     * @param inverseModelBindMatrix the joint's inverse model bind matrix (not
+     * null, unaffected)
+     * @param parent the joint's parent, or null for a root joint
+     */
     void applyBindPose(Transform localTransform, Matrix4f inverseModelBindMatrix, Joint parent);
 
+    /**
+     * Determine the joint's transform in model space.
+     *
+     * @return a new instance or a pre-existing one
+     */
     Transform getModelTransform();
 }