The Importance of Resolution in CG - An Introduction to Computer Graphics for Artists - page 88

Chapter 7
The Importance of Resolution in CG

7.1 Introduction

In a study of an ecological disaster in Poland, researchers used satellite photos of
the region to determine the scale of the area affected. In another section of the same
article, scanning microscope photographs are reproduced to show the effect of this
event on the soil in the area (Rahmonov and Ole

2010 ) . What this study illustrates
to the would-be CG artist is that there is always more detail, from the extremely
large to the very small. No matter how accurate or complete you want your work to
be, you must always leave a great deal out if you are to fi nish (Fig. 7.1 ). There is no
practical way to establish an end point to the amount of information any given
object contains, so it becomes the CG artist's job to decide at what level of resolution
a thing should be built.
“Resolution” to a CG artist refers to the level of detail that will be used to represent
something in a 3D fi le. The type of detail can vary, so the word does not refer to a
single type of resolution. With polygonal models the resolution is the number of
polygons. With texture maps, it is the number of pixels, expressed as X and Y axis
dimensions of a two dimensional image. Curve resolution is effectively infi nite if
represented by NURBS curves (see Sect. 14.2 ) , but for the purpose of making a
rendering, curves are converted to triangles and can be measured as polygons. Any
element in CG can be described as having a “resolution” in the sense that each
requires the use of bytes to store information related to the element, and the more
data is stored, the higher the resolution is.
Resolution is important to the CG artist because as a concept it provides a method
to control the expenditure of limited resources. The Random Access Memory
(RAM), hard drive storage space, Central Processing Unit (CPU) bandwidth,
Graphics Processing Unit (GPU), and time available for rendering or other calcula-
tions are all limited. Artists are required to work within the limitations imposed
by the limited supply of memory, bandwidth, space, and time. To do this well requires
knowledge and some skill.

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