LightProbeHelperGPU: Fix uniform update. (#29303)

* LightProbeHelperGPU: Clean up.

* LightProbeHelperGPU: Fix uniform update.

* Clean up.

examples/jsm/helpers/LightProbeHelperGPU.js

@@ -36,6 +36,7 @@ class LightProbeHelper extends Mesh {
 		this.type = 'LightProbeHelper';
 
 		this._intensity = intensity;
+		this._sh = sh;
 
 		this.onBeforeRender();
 
@@ -54,6 +55,9 @@ class LightProbeHelper extends Mesh {
 
 		this.scale.set( 1, 1, 1 ).multiplyScalar( this.size );
 
+		this._intensity.value = this.lightProbe.intensity;
+		this._sh.array = this.lightProbe.sh.coefficients;
+
 	}
 
 }