1. A method for calculating values for pixels of an image of an environment represented by geometric primitives that are defined by geometric data, the method comprising: transforming the geometric primitives from a first coordinate space to a second coordinate space; shifting a transformed primitive by a first sub-pixel offset; rendering the shifted primitive to generate values for pixels of a first intermediate image; shifting the transformed primitive by a second sub-pixel offset; rendering the shifted primitive to generate values for pixels of a second intermediate image; and combining the values for the respective pixels of the first and second intermediate images to determine the values for the pixels of the image.