Cinema 4D / BodyPaint 3D Program Documentation Tutorials Light and Shadow Tutorial Visualizing Interior Spaces using Global Illumination
Function available in CINEMA 4D Visualize, Studio

Materials

The scene’s materials are fairly easy to create without using special shader combinations. Because the room is lit using Global Illumination all materials should have reflective properties. This is necessary because the indirect lighting, which is created by luminous materials, does not generate its own specular light as normal lights would. In the following, several materials used in the scene are described in detail. Several image textures will also be explained. Of course you can also use your own textures but if you want to use the textures supplied you will find them in the ,tex/tutorials’ folder in your Cinema 4D installation directory.

The materials are arranged alphabetically in the Material Manager at the bottom left. Many of the materials used in this scene are simply made up of colors and can simply be dragged onto various objects. Many are copies, which helps keep the scene organized. We will concentrate on the more complex materials in the scene. You can decide which materials should be assigned to which objects.

Aluminium

The first material we will create will simulate aluminum and will, for example, be assigned to the window shades, table legs and lamps. Since metal surfaces generally have reflective properties, the material’s Reflectance channel should be enabled. Set the Default Specular layer’s Type to GGX and its Attenuation to Metal to make sure that the reflections look natural (the more reflective a metal surface is, the less diffuse its color will be). The last value we will modify is the Roughness value - set it to 20%. This will blur reflected elements in relation to their distance from the surface. The reflection is also dependent on the angle from which the surface is viewed. For example, water displays little reflectivity when viewed from above and reflects correspondingly more light as the angle of view to the surface increases. This effect is called the Fresnel effect (named after the French physicist Augustin-Jean Fresnel who was the first to document it. For our material we will need to set Fresnel to Conductor and Preset to Aluminum in the material’s Layer Fresnel menu. This will automatically set the index of refraction (IOR) value to a physically correct 1.44.

Only this material will use an additional layer for specular highlights. In the Layers tab, click on the Add … button and select Phong. Set its Attenuation to Metal. This will supplement the metal look of the surface (even though no light source will be used in the scene) because it changes the overall look of the highlight. Increase the Roughness value to 78% and set Specular Strength to 150%.

For the ceiling lights (spot lights), copy the aluminum material and modify it slightly. All you basically have to do is increase the IOR value to 3 in the Layer Fresnel menu.

Floor

The next material will be for the floor (planks). We will only use the Color and Reflectance channels for this material. In the Color channel, load the texture PlanksWood.tif into the Texture Field (you can also use your own image if you like). Load the same image into the Reflectance channel’s Layer Color menu and reduce this Brightness value to 70%. Also, set the Mix Mode to Multiply. Set the layer’s Type to Beckmann with a Roughness of 20% and Attenuation set to Average.

To prevent reflections from being rendered in the seams and cracks of the wood, set Fresnel to Conductor in the Layer Fresnel menu and reduce the IOR slightly to 1.33.

Plastic - black

The third material will simulate black plastic (Plastic - Black), which can be applied to several objects that have similar surface properties, e.g., chair legs and lamps. Since the color will be black, we only need to enable the Reflectance channel for this material. Set its Type to Beckmann with Attenuation set to Average and a Roughness of 20%. In the Layer Fresnel menu, set Fresnel to Dielectric with an IOR value of 1.575.

For some objects, a modified version of this material (Plastic - White) can be used. Simply change the color accordingly and set its Brightness to 90%. This slightly modified material with a texture added (Textures.jpg; Textures2.jpg) will also be used for the books.

Wall - black

This material (Wall - Black) will be applied to the wall on the right-hand side. By reducing the Brightness to 5%, the color will turn gray. In the Reflectance channel we will use the same method as for the floor only that we will also add a Noise shader in the Layer Color menu that will be multiplied with a Fresnel shader in the Layer Shader menu. Set the Noise to Wavy Turbulence with a Global Scale of 200% and an IOR value of 1.2. We will also use the Noise in the Bump channel and set its Strength to 10% to make the surface look rough. We will do without the Layer Fresnel settings altogether.

Wood - Red

The last material, Wood - Red) will be applied to the designer chair. This material is set up similar to the wall material but we will use the integrated Wood shader instead of a bitmap. The Color values should be set to various shades of gray and all other settings can be left at their default values. In the Color channel, set Mix Mode to Multiply and define a sturdy red Color.

Since we used shades of gray for the Wood shader we can also use these in the Reflectance channel and multiply them with the Fresnel effect. If we simply duplicate the entire material all we need to do is change the red in the Color channel to 10% gray to produce the black wood pattern.

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