code: function initGL () {
  
  		try {
  
  			if ( ! ( _gl = _canvas.getContext( 'experimental-webgl', { alpha: _alpha, premultipliedAlpha: _premultipliedAlpha, antialias: _antialias, stencil: _stencil, preserveDrawingBuffer: _preserveDrawingBuffer } ) ) ) {
  
  				throw 'Error creating WebGL context.';
  
  			}
  
  		} catch ( error ) {
  
  			console.error( error );
  
  		}
  
  		_glExtensionTextureFloat = _gl.getExtension( 'OES_texture_float' );
  		_glExtensionStandardDerivatives = _gl.getExtension( 'OES_standard_derivatives' );
  
  		_glExtensionTextureFilterAnisotropic = _gl.getExtension( 'EXT_texture_filter_anisotropic' ) ||
  											   _gl.getExtension( 'MOZ_EXT_texture_filter_anisotropic' ) ||
  											   _gl.getExtension( 'WEBKIT_EXT_texture_filter_anisotropic' );
  
  
  		if ( ! _glExtensionTextureFloat ) {
  
  			console.log( 'THREE.WebGLRenderer: Float textures not supported.' );
  
  		}
  
  		if ( ! _glExtensionStandardDerivatives ) {
  
  			console.log( 'THREE.WebGLRenderer: Standard derivatives not supported.' );
  
  		}
  
  		if ( ! _glExtensionTextureFilterAnisotropic ) {
  
  			console.log( 'THREE.WebGLRenderer: Anisotropic texture filtering not supported.' );
  
  		}
  
  	}
docs: Initialization