NaimExplain

Provide an example of an artificial spatial cue. Why are these used? Answer: Enhance 3d scatter plots by dropping a line from each points, without those lines, only 2d judgement of spatial layer is possible. With those lines, we can estimate the points' 3D position.

Provide two examples of where perspective is intentionally distorted in 20th century art. Why might this be effective? The Disney Princess castle - Made to look much larger and further away than it is. This is done by using smaller bricks at the top of the tower, which progressively get larger. Also, the houses lining the street to the castle progressively get larger (We perceive things that are smaller as further away). This is useful in creating a sense of wonder for those visiting the park Julian Beever - Creates chalk drawings that look 3d by distorting the images he draws themselves, this again creates a sense of wonder when viewed from the correct perspective (has to be viewed from correct perspective)

How does one make a three-dimensional postcard? Answer: Lenticular images combine digitally interlaced printed or photographic image with rows of optical grade lenses. They focus light on different strips of the surface and magnifies whatever image is there. Viewing the image from different angles - by moving - creates the desired illusion.

Describe the relationship between 'shape from shading' and the position of the light source. Shape can be recovered from a single image by human visual system based on the shading information. To estimate the shape from a single image, some assumptions have to be made, e.g. constant albedo (surface color). This technique is very useful for reconstructing surfaces of planets from photographs acquired by spacecrafts. For example, the concave/convex ambiguity

Describe each system and provide at least one perceptual disadvantage for each of the following three-dimensional display methods: Chromadepth glasses have a ridged surface, made up of little prisms. Looking really closely reveals that you are looking through alot of little prisms. It bends light at different wavelengths to different extents. ADVANTAGES- cheap viewing equipment needed disadvantages, color is tied to depth. Red seems close, blue seems far

Describe each system and provide at least one perceptual disadvantage for each of the following three-dimensional display methods: Passive polarization 1. Two films taken at two different positions 2. Two films projected trough polarizers onto silver oxide screen 3. Audience must wear polarized glasses Advantages- large audiences, motion, color disadvantages- expensive silver oxide screen, ghosting, polarizers reduce intensity

Describe each system and provide at least one perceptual disadvantage for each of the following three-dimensional display methods: Autostereogram The trick is to display slightly different images to the two eyes. The autostereogram works by having repetitive patterns. To see depth in an autostereogram, you need to either cross or diverge your eyes so that they fixate separately on two different repeats of a repetitive pattern. In this way, you effectively get two different images to the two eyes.