1. A method of generating image data for use in image based lighting rendering, the method including: displaying a user interface, separate from and communicably coupled to a displayed three-dimensional scene to be rendered in an image based lighting process, the user interface being in the form of a two-dimensional canvas representing an inner surface of a three-dimensional volume surrounding the three-dimensional scene to be rendered, each point on the two-dimensional canvas representing a surface coordinate of the three-dimensional scene to be rendered in the image based lighting rendering and corresponding to a longitude/latitude on said inner surface of said three-dimensional volume, said displayed two-dimensional canvas adapted to include at least one two-dimensional shape having an associated lightness value, said shape being distorted within said displayed two-dimensional canvas to define an undistorted representation thereof in said three-dimensional scene; receiving, via a computer, user input via interaction with said displayed two-dimensional canvas, said user input describing creation of the at least one two-dimensional shape having an associated lightness value or modification of said at least one two-dimensional shape within said displayed two-dimensional canvas; using the computer to update the displayed two-dimensional canvas in accordance with the user input to display said two-dimensional canvas including said created/modified at least one two-dimensional shape distorted within said displayed two-dimensional canvas to define an undistorted representation thereof within said three-dimensional scene; and using the computer to generate the image data describing the distorted representation of the at least one two-dimensional shape for use in graphics rendering of the three-dimensional scene, wherein said image data is lighting image data derived from said displayed two-dimensional canvas including said created/modified at least one two-dimensional shape, and said at least one shape is representative of a light source included in said lighting image data and for use in a graphical rendering process.