3D in Depth: Materials, Pt. 1. | 2
3D in Depth: Materials, Pt. 1.
3D programs have several methods of managing textures and synthetic surfaces around objects. As an example, 3D Studio Max makes use of the Material Editor, which allows you to select, apply, edit, delete and create new materials in the current scene. The newly created materials can also be saved for use in other scenes.
When working with a rendered surface, the reflective quality depends on three elements: Ambient, Diffuse, and Specular.
Ambient controls how much of the global ambient color the material responds to. The main use of Ambient is to fill in shadows that are too dark. It can also be used for controlling the contrast of an object when used in combination with Diffuse. Surfaces with a high ambient value and a low diffuse value will appear flatter and darker. Surfaces with a low ambient value and a high diffuse value will have darker shadows.
Diffuse controls the intensity of the diffused light that is reflected from the object. This is the dominant color on the sample sphere, occupying the center and upper areas.
Specular controls the intensity and color of the reflected highlight. When the Specular color is white, the surface reflects all the light hitting it. If the Specular color is any other color it will modify the color of the light hitting it. The Specular color is shown on the upper left area of the sphere.
Another group of options commonly present are Shaders. A couple of these are Phong and Metal.
Phong: This is a commonly used option and is excellent for representing plastic surfaces.
Metal: With this option there is no Specular highlight, though glancing highlights are much brighter.
Another group of controls are available to manipulate the appearance of objects. A few of these options are: Shininess, Shininess Strength, Self-Illumination and Opacity.
Shininess is used to increase or decrease the size of a highlight.
Shininess Strength is used to increase or decrease the intensity of a highlight.
Self-Illumination Using this option makes the object appear as if it’s lit form within.
Opacity controls the transparency of an object.
A common option for controlling color in 3D programs is the color selector, which allows you to set the Hue, Saturation or Lightness (HSV) of a color or gives you control of the Red, Green, and Blue (RGB) values.
Texture Maps, etc.
In 3D, another set of mapping tools that adds great power to your images are Texture Maps, Procedural Maps, Bitmaps, and Bump Maps. Texture Mapping is where you take raster imagery and apply it to 3D geometry. This imagery can be a procedural texture (a pattern created by software such as fractals or noise), images from real life or custom created textures in applications such as Photoshop, Painter, etc.
Above is an example of a procedural map, followed by an example of a texture map created from a satellite shot of clouds.
Where textures in 3D really develop their power is when you can combine textures to create a certain effect, such as in the mask above. You can read more about how this mask was created here.
The texture here is actually made up of two bitmaps of cracked paint, layered together to form one texture.
The second part of the mask that makes it work is the Bump Map, which creates the illusion of depth. These images are combined in software as a Composite Map, which allows you to layer images and apply transparency between the layers, among other things.
It is beyond the scope of this article to list the wide range of options available, but I wanted to give you a taste of what options exist. Beyond that, you’ll need to do some exploration on your own and to look at some of the books listed in the Reference section.
Next month, we’ll look deeper into the subject of creating textures using photography and scanning. I’ll also cover basic traditional painting techniques, where you will see how to create effects using sponging, dry brush, layering, blending, impasto and other effects. Next, I'll photograph the textures and bring them into Photoshop, where they will be converted into seamless tileable textures.
Created: June 5, 2003
Revised: February 9, 2004