Use cameraPosition uniform instead of world origin (#26766)

Author: StrandedKitty

Diff for: examples/jsm/objects/Sky.js

@@ -138,8 +138,6 @@ Sky.SkyShader = {
 		uniform float mieDirectionalG;
 		uniform vec3 up;
 
-		const vec3 cameraPos = vec3( 0.0, 0.0, 0.0 );
-
 		// constants for atmospheric scattering
 		const float pi = 3.141592653589793238462643383279502884197169;
 
@@ -169,7 +167,7 @@ Sky.SkyShader = {
 
 		void main() {
 
-			vec3 direction = normalize( vWorldPosition - cameraPos );
+			vec3 direction = normalize( vWorldPosition - cameraPosition );
 
 			// optical length
 			// cutoff angle at 90 to avoid singularity in next formula.