Color And Other Attributes Of Objects

In addition to the geometry itself, we often need to specify properties of an object such as its color, which affect its appearance. In this chapter you will be introduced to the most common attributes, and learn how they can be managed. The objects we have drawn so far have all been white. However, we can easily specify that an object should be drawn in some other color by using the Color command. Though RenderMan supports more complex forms of color control, practically in all cases this is followed by three values enclosed in square brackets, specifying the amount of red, green, and blue required in the object. For example, if you want to make an object red you simply need to add the command: Color [1 0 0]. Like transforms, colors apply to everything that follows them, so the code in Listing 9.1 produces two red spheres. Of course this color is only a starting point for determining the color the object will appear in the rendered scene, as lighting and other shading effects must be taken into account, but in most cases Color is used as the basis of the final result.