Merge pull request #13106 from donmccurdy/docs-frostbite-pbr-link

Fix links to Frostbite PBR document

src/lights/PointLight.js

@@ -17,14 +17,14 @@ function PointLight( color, intensity, distance, decay ) {
 		get: function () {
 
 			// intensity = power per solid angle.
-			// ref: equation (15) from http://www.frostbite.com/wp-content/uploads/2014/11/course_notes_moving_frostbite_to_pbr.pdf
+			// ref: equation (15) from https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf
 			return this.intensity * 4 * Math.PI;
 
 		},
 		set: function ( power ) {
 
 			// intensity = power per solid angle.
-			// ref: equation (15) from http://www.frostbite.com/wp-content/uploads/2014/11/course_notes_moving_frostbite_to_pbr.pdf
+			// ref: equation (15) from https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf
 			this.intensity = power / ( 4 * Math.PI );
 
 		}

src/lights/SpotLight.js

@@ -21,14 +21,14 @@ function SpotLight( color, intensity, distance, angle, penumbra, decay ) {
 		get: function () {
 
 			// intensity = power per solid angle.
-			// ref: equation (17) from http://www.frostbite.com/wp-content/uploads/2014/11/course_notes_moving_frostbite_to_pbr.pdf
+			// ref: equation (17) from https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf
 			return this.intensity * Math.PI;
 
 		},
 		set: function ( power ) {
 
 			// intensity = power per solid angle.
-			// ref: equation (17) from http://www.frostbite.com/wp-content/uploads/2014/11/course_notes_moving_frostbite_to_pbr.pdf
+			// ref: equation (17) from https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf
 			this.intensity = power / Math.PI;
 
 		}