Clean up.

src/materials/MeshDistanceMaterial.js

@@ -55,7 +55,7 @@ class MeshDistanceMaterial extends Material {
 
 	copy( source ) {
 
-		super.clone( source );
+		super.copy( source );
 
 		this.referencePosition.copy( source.referencePosition );
 		this.nearDistance = source.nearDistance;

src/materials/MeshMatcapMaterial.js

@@ -77,7 +77,7 @@ class MeshMatcapMaterial extends Material {
 
 	copy( source ) {
 
-		super.clone( source );
+		super.copy( source );
 
 		this.defines = { 'MATCAP': '' };
 

src/materials/MeshNormalMaterial.js

@@ -66,7 +66,7 @@ class MeshNormalMaterial extends Material {
 
 	copy( source ) {
 
-		super.clone( source );
+		super.copy( source );
 
 		this.bumpMap = source.bumpMap;
 		this.bumpScale = source.bumpScale;

src/materials/MeshToonMaterial.js

@@ -97,7 +97,7 @@ class MeshToonMaterial extends Material {
 
 	copy( source ) {
 
-		super.clone( source );
+		super.copy( source );
 
 		this.color.copy( source.color );
 

src/materials/PointsMaterial.js

@@ -42,7 +42,7 @@ class PointsMaterial extends Material {
 
 	copy( source ) {
 
-		super.clone( source );
+		super.copy( source );
 
 		this.color.copy( source.color );