setupVariants( /*builder*/ ) {

		// SHININESS

		const shininessNode = ( this.shininessNode ? float( this.shininessNode ) : materialShininess ).max( 1e-4 ); // to prevent pow( 0.0, 0.0 )

		shininess.assign( shininessNode );

		// SPECULAR COLOR

		const specularNode = this.specularNode || materialSpecular;

		specularColor.assign( specularNode );

	}
Setups the phong specific node variables.

@param {NodeBuilder} builder - The current node builder.