Clarify range of attenuationDistance (#24917)

docs/api/en/materials/MeshPhysicalMaterial.html

@@ -90,7 +90,7 @@
 
 		<h3>[property:Float attenuationDistance]</h3>
 		<p>
-		Density of the medium given as the average distance that light travels in the medium before interacting with a particle. The value is given in world space. Default is `Infinity`.
+		Density of the medium given as the average distance that light travels in the medium before interacting with a particle. The value is given in world space units, and must be greater than zero. Default is `Infinity`.
 		</p>
 
 		<h3>[property:Float clearcoat]</h3>

docs/api/it/materials/MeshPhysicalMaterial.html

@@ -94,6 +94,7 @@
 		<p>
 			Densità del mezzo, data come distanza media percorsa dalla luce nel mezzo prima di interagire con una particella.
 			Il valore è indicato nello spazio del mondo. Il valore predefinito è `0`.
+			Density of the medium given as the average distance that light travels in the medium before interacting with a particle. The value is given in world space units, and must be greater than zero. Default is `Infinity`.
 		</p>
 
 		<h3>[property:Float clearcoat]</h3>

docs/api/zh/materials/MeshPhysicalMaterial.html

@@ -81,7 +81,7 @@
 
 		<h3>[property:Float attenuationDistance]</h3>
 		<p>
-		Density of the medium given as the average distance that light travels in the medium before interacting with a particle. The value is given in world space. Default is *0*.
+		Density of the medium given as the average distance that light travels in the medium before interacting with a particle. The value is given in world space units, and must be greater than zero. Default is `Infinity`.
 		</p>
 
 		<h3>[property:Float clearcoat]</h3>