The term “drafting services” encompasses several activities. Examples are 2D drafting, 3D drafting and 3D visualization. The subject of this article is 3D visualization, and some of the on-the-ground realities associated with it.
3D visualization is the creation of a computer-generated drawing which is remarkably lifelike, so lifelike that the viewer must wonder, “Is that a computer-generated drawing or a photograph?”
The process of 3D visualization creation can be broadly divided into two steps: model creation and rendering.
This entails creation in the computer’s memory of a 3D object that looks exactly like the target, real-world object. The 3D visualization expert uses one or more photographs of the object or perhaps 2D drawings of it as input information. Although the 3D visualization expert will inevitably have specialized drafting skills and spatial conceptualization ability of a high order, he can take hours, days or months to create the object depending on how much detail is in it.
The completed model typically looks totally gray; also, there is no light falling on it and it therefore generates no shadows. The surface colors, lighting and shadows are created in the second step, i.e. rendering.
During this stage the 3D visualization expert specifies to the computer the surface finish of every part of the object as well as the intensity, color and position of the various lights that shine on th drafting services e object. Examples of surface finishes (also called ‘textures’) would be “metallic red”, ‘beige linen” and “green moss”. Examples of lights would be “daylight”, “spotlight” and “directional light”.
Once the computer has texture and lighting information, it pastes the specified surface finishes onto the appropriate surfaces and places lights of the specified intensity and color at the positions decided by the 3D visualization expert. It then draws light rays from every light source to its final destination. A ray could travel from a spotlight to an object, then bounce off the object at the angle of reflection, hit another object, be reflected onto a third object, etc., losing intensity as it progresses along the path. When millions of light rays are drawn in this way, the result is a very realistic illumination of the object and its surrounds, complete with shadows and reflections (this is known as a ‘photorealistic rendering’).
As one might imagine, the rendering process consumes enormous computing resources due to the very large number of light rays that have to be drawn. To render one scene consisting of a house surrounded by vegetation can often10 hours or more on the fastest desktop. If animation has to be created, which usually calls for 24 images per second, a 10-second animation would comprise 240 images, and the time taken to