1. A method of generating image data for use in image based lighting rendering, the method including: displaying a two-dimensional canvas, each point on the two-dimensional canvas representing a surface coordinate of a three-dimensional scene to be rendered in the image based lighting rendering, said displayed two-dimensional canvas including at least one 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 at least one shape having an associated lightness value or modification of said at least one 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 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 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 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.