A rendering method for a plurality of users of an autostereoscopic display comprising a plurality of pixels and an optical layer having optical elements (104, 105), each of the optical elements being configured to generate a different viewing cone from each of the plurality of the pixels, the method comprising: tracking both eyes (513, 516) of a first user and both eyes (533, 536) of a second user so as to determine a respective position of both eyes of the first user and both eyes of the second user, wherein the users view each pixel through different viewing cones; determining an order of priority of the first and second users, the first user having the higher priority; mapping the positions of both eyes of a first user and the positions of both eyes of a second user to a single one of the viewing cones, wherein the mapping is based on the relative position between the pixel and the optical elements of the optical layer, and such that the rays by which the pixel is viewed in each eye through the respective optical element are mapped to the single viewing cone as though the pixel were viewed through the optical element corresponding to the single viewing cone; and determining an image value of the pixel to be projected into the viewing cones to the users, wherein the determining comprises: determining a ray direction of the pixel within the single viewing cone; and determining the image value of the pixel based on the priority of the first and second users, to ensure that at least the first user views a stereo image from different pixels; wherein in response to the ray direction of the pixel corresponding to a mapped position of an eye of the first user, which is adjacent to a mapped position of an eye of the second user at a predetermined distance for image separation, the value of the pixel to display an appropriate view image of a stereo image for the eye of the first user is determined. tracking both eyes (513, 516) of a first user and both eyes (533, 536) of a second user so as to determine a respective position of both eyes of the first user and both eyes of the second user, wherein the users view each pixel through different viewing cones; determining an order of priority of the first and second users, the first user having the higher priority; mapping the positions of both eyes of a first user and the positions of both eyes of a second user to a single one of the viewing cones, wherein the mapping is based on the relative position between the pixel and the optical elements of the optical layer, and such that the rays by which the pixel is viewed in each eye through the respective optical element are mapped to the single viewing cone as though the pixel were viewed through the optical element corresponding to the single viewing cone; and determining an image value of the pixel to be projected into the viewing cones to the users, wherein the determining comprises: determining a ray direction of the pixel within the single viewing cone; and determining the image value of the pixel based on the priority of the first and second users, to ensure that at least the first user views a stereo image from different pixels; wherein in response to the ray direction of the pixel corresponding to a mapped position of an eye of the first user, which is adjacent to a mapped position of an eye of the second user at a predetermined distance for image separation, the value of the pixel to display an appropriate view image of a stereo image for the eye of the first user is determined. determining a ray direction of the pixel within the single viewing cone; and determining the image value of the pixel based on the priority of the first and second users, to ensure that at least the first user views a stereo image from different pixels; wherein in response to the ray direction of the pixel corresponding to a mapped position of an eye of the first user, which is adjacent to a mapped position of an eye of the second user at a predetermined distance for image separation, the value of the pixel to display an appropriate view image of a stereo image for the eye of the first user is determined.