Docs: Improve `displacementMap` JSDoc. (#33453)

src/materials/MeshLambertMaterial.js

@@ -181,7 +181,9 @@ class MeshLambertMaterial extends Material {
 		 * displaced vertices can cast shadows, block other objects, and otherwise
 		 * act as real geometry. The displacement texture is an image where the value
 		 * of each pixel (white being the highest) is mapped against, and
-		 * repositions, the vertices of the mesh.
+		 * repositions, the vertices of the mesh. For best results, pair a
+		 * displacement map with a matching normal map, since the renderer can
+		 * not recompute surface normals from the displaced vertices.
 		 *
 		 * @type {?Texture}
 		 * @default null

src/materials/MeshMatcapMaterial.js

@@ -123,7 +123,9 @@ class MeshMatcapMaterial extends Material {
 		 * displaced vertices can cast shadows, block other objects, and otherwise
 		 * act as real geometry. The displacement texture is an image where the value
 		 * of each pixel (white being the highest) is mapped against, and
-		 * repositions, the vertices of the mesh.
+		 * repositions, the vertices of the mesh. For best results, pair a
+		 * displacement map with a matching normal map, since the renderer can
+		 * not recompute surface normals from the displaced vertices.
 		 *
 		 * @type {?Texture}
 		 * @default null

src/materials/MeshNormalMaterial.js

@@ -88,7 +88,9 @@ class MeshNormalMaterial extends Material {
 		 * displaced vertices can cast shadows, block other objects, and otherwise
 		 * act as real geometry. The displacement texture is an image where the value
 		 * of each pixel (white being the highest) is mapped against, and
-		 * repositions, the vertices of the mesh.
+		 * repositions, the vertices of the mesh. For best results, pair a
+		 * displacement map with a matching normal map, since the renderer can
+		 * not recompute surface normals from the displaced vertices.
 		 *
 		 * @type {?Texture}
 		 * @default null

src/materials/MeshPhongMaterial.js

@@ -196,7 +196,9 @@ class MeshPhongMaterial extends Material {
 		 * displaced vertices can cast shadows, block other objects, and otherwise
 		 * act as real geometry. The displacement texture is an image where the value
 		 * of each pixel (white being the highest) is mapped against, and
-		 * repositions, the vertices of the mesh.
+		 * repositions, the vertices of the mesh. For best results, pair a
+		 * displacement map with a matching normal map, since the renderer can
+		 * not recompute surface normals from the displaced vertices.
 		 *
 		 * @type {?Texture}
 		 * @default null

src/materials/MeshStandardMaterial.js

@@ -221,7 +221,9 @@ class MeshStandardMaterial extends Material {
 		 * displaced vertices can cast shadows, block other objects, and otherwise
 		 * act as real geometry. The displacement texture is an image where the value
 		 * of each pixel (white being the highest) is mapped against, and
-		 * repositions, the vertices of the mesh.
+		 * repositions, the vertices of the mesh. For best results, pair a
+		 * displacement map with a matching normal map, since the renderer can
+		 * not recompute surface normals from the displaced vertices.
 		 *
 		 * @type {?Texture}
 		 * @default null

src/materials/MeshToonMaterial.js

@@ -181,7 +181,9 @@ class MeshToonMaterial extends Material {
 		 * displaced vertices can cast shadows, block other objects, and otherwise
 		 * act as real geometry. The displacement texture is an image where the value
 		 * of each pixel (white being the highest) is mapped against, and
-		 * repositions, the vertices of the mesh.
+		 * repositions, the vertices of the mesh. For best results, pair a
+		 * displacement map with a matching normal map, since the renderer can
+		 * not recompute surface normals from the displaced vertices.
 		 *
 		 * @type {?Texture}
 		 * @default null