The materials used in this room are fairly basic, with almost none containing complex shader combinations. Because we will illuminate one version of the room only using Global Illumination, it should be noted that almost all materials should be assigned a reflective property. This method of calculation however does not generate Specular Highlights when luminous materials are used, as we are used to seeing with light sources. In the following, the makeup of several of the materials used in the scene are described in detail.
Occasionally image textures will be mentioned. Of course you are free to use your own image textures but if you want to use the textures from the scene itself they are located in the /tex / tutorials] folder in your Cinema 4D installation directory.
Many of the materials used in this scene are only comprised of colors and can simply be dragged and dropped onto an object. These materials include all white and red plastic surfaces as well as the walls. We will concentrate on the more complex materials and describe these in detail. Let’s begin with the television screen.
One special characteristic of this material is the fact that this surface emits light in a real-world situation. The television screen will illuminate the area around it. The screen in our example is lit dimly so we will use a dark gray as a base color and overlay a bitmap which depicts the graphic for the screen. Overlaying the bitmap will make it possible to maintain the intensity of the graphic if more light hits the screen. If only luminous characteristics are used the image brightness will remain the same in any lighting situation.
The same image file used for the television image is used in the material’s Luminance channel. The image’s brightness was directed more towards the object elements that face the viewer by multiplying it with a Fresnel shader (whose gradient was inverted) in a Layer shader. This is a more realistic lighting scenario. The Mix Mode can be set to Multiply can be applied for additional control over Brightness and Luminance. This is illustrated in the image below:
Furthermore, the television screen is also smooth and reflective, which should also be simulated by the material. As is shown in the image below, a reflective strength of 10% with a sharp specular highlight will do the trick. At the right of the image below you can see how the material is applied to the television using the Cubic Projection type. Make sure the image proportions match the proportions of the television screen so the image does not look distorted.
Books and DVDs
The book covers and DVD casings are easy to texture. Just make sure the DVD casings are more reflective and shiny than the books. If you have a row of books or DVDs, as shown at the right of the image below, you do not have to model and texture each one individually.
In the example above, a simple cube was scaled to the appropriate size and a texture applied that depicts a row of DVDs sitting on a shelf. A Bump channel was applied that contains a modified version of the colored image in order to add more depth to the texture. In many cases, the original colored image simply has to be converted to a grayscale image with a greatly increased contrast so it can be used as a bump mapin the Bump channel. Depending on how the DVDs will be viewed in the scene, a simple Cubic Projection type will often suffice. For books, however, the recessed pages should generally be modeled separately from the front and back covers. These pages can then simply be colored white (again, depending on how closely the camera will view these objects). A book’s spine can be created using a u-shaped Extrude object. All of this bears the advantage that the UV coordinates will automatically be created correctly, letting you apply a texture with to the front, back and spine of the book in a single step.
Above the television, two large colored canvases can be seen hanging on the wall. Similar textures can even be used to simulate rocky surfaces, wallpaper or stucco. The red canvas has a base color of dark red, over which a bitmap with varying shades of violet will be placed. In this case, the makeup of this material’s Bump channel is quite interesting. It has a layer shader, which combines a bitmap image with a Rust shader. The Rust shader is part of the Surfaces group of shaders. It uses a gradient that defines the color of the surface with intermittent areas of differing color. As you can see in the image below you do not have to apply a grayscale gradient - the Bump channel will automatically interpolate any grandient’s brightness values. The image below shows the bitmaps used in the material.
The structure of the bitmap used in our example is quite complex in itself, which also bears a disadvantage: if the material is tiled a visible repetition of the bitmap’s structure will result. Mixing this bitmap with a Rust shader will help remedy this. The Rust shader is not restricted by the tiling material but will have a different variation for each tile. The image below shows the required Reflectance channel and the specular settings. As already mentioned, a material’s reflective properties will only be visible if the material is illuminated.
The white canvas has a similar makeup to the red canvas. The only difference is that its material was created using no shaders at all. The Relief was created using a grayscale bitmap image and the color was not modified. The image below shows the material channel’s settings and the bitmap image that was used.
The floor is made up of implied wooden planks with a white varnish. Hence, the grain and plank structure is only slightly visible, making the floor’s dominant characteristics its color and reflection. To achieve this, the floor material was given a white color whose brightness can only slightly be varied via the Diffusion channel and the bitmap image of the wooden planks therein. The brightness is varied by reducing the Mix Strength while maintaining a Brightness value of 100% in the Diffusion channel. The image below shows the material’s settings and the bitmap image used.
In addition to a slight reflection, the same image will be used in the Bump channel (at the bottom right of the image below). The Strength value will, however, be kept low. The image itself has a rather low contrast, making it more difficult to make out the individual planks. The specular highlight has also been kept quite subdued:
The Cubic Projection type was used to apply the material to the floor. This allows the size of the material’s structure as well as its orientation to be easily modified.
Across from the television are two designer neon lights above the sofas. Initially, these will appear "off" in the scene. Therefore, we will create a translucent glass material for these neon tubes using a Fresnel gradient in the Color channel. This will make the glass tubes look darker at the edges, as real neon tubes do. Of course, a glass tube also requires a somewhat stronger reflective property as well as a more intense specular highlight. The image below shows the corresponding material settings as well as a close-up view of the neon tubs in the Viewport. Simply drag the material as it is onto the tube objects.
Throughout the room are numerous red trim and decorative elements on the walls. This material consists of a bright red in the Color channel, a Specular highlight and a slight Reflection. The image below shows these settings in detail:
The material for the seat cushions/upholstery is somewhat more complicated. We want to avoid a "plastic" look and give the material some type of pattern. We will begin by adding a Fresnel shader to the material’s Color channel. A cloth’s brightness often varies according to the angle from which it is viewed. We will define the gradient’s colors so the surfaces that curve away from the viewer will appear lighter, less saturated. We will also add a simple Noise shader with a Mix Strength of 10% to the Diffusion channel to break up the surface shading somewhat.
In this case we will use the Reflectance channel more extensively for the cloth surface. Set Type to Irawan (Woven Cloth), which will allow a broad dispersion of the highlight and also make the Layer Cloth menu available, which we will use to define the textile’s complete structure. Define various red tones for the diffuse and specular properties and finally a Pattern to simulate the cloth’s surface. The image below shows how the upholstery looks when rendered with the above-described settings.