A method of generating data for use in image based lighting rendering, including displaying a 2-dimensional canvas (202), each point on the 2-dimensional canvas representing a surface co-ordinate of a 3-dimensional object having at least one surface. User input describing creation/modification of at least one shape (205, 205′) having an associated lightness value for use in image based lighting rendering is received via the 2-dimensional canvas. The 2-dimensional canvas is updated in accordance with the user input to display a representation of the at least one shape as created/modified by the user input, the representation on the canvas being distorted to indicate mapping of the at least one shape with respect to at least one said surface of the 3-dimensional object. Data describing the at least one shape for use in graphics rendering is generated.