Assigning and Projecting Materials
If a material only contains descriptive properties such as color, specularity, reflectivity or transparency and no textures, its preview icon can simply be dragged from the Material Manager onto the respective object in the Viewport or Object Manager. You don’t have to worry about the direction in which the material is project, its projection type or size. If the object to which the material is assigned has Child objects the material will automatically be assigned to these as well. However, if a material contains a texture in the form of an image or a shader with a pattern, the parameters in the Texture Tag, which is automatically created in the Object Manager once the material is applied, will have to be taken into account. With this tag’s parameters you can define properties such as size, how often it is repeated on an object and the type of projection. The projection type can be based on primitive shapes such as a cube, sphere, cylinder or plane - or can be based on UV coordinates. These 2D coordinates can, for example, be created individually for each point of a polygonal object with the help of BodyPaint 3d. Other objects, such as parametric Primitives and all Spline-based Generator objects, automatically create UV coordinates, which simplify the application of materials with textures. Thanks to UV coordinates, each section of a material can be assigned precisely to a specific region of a given surface. This also makes it possible to project a texture around the edge of an object. However, simple shapes can be assigned a standard projection type for good results. Below is a description of the various options available when applying materials:
After a material has been assigned to an object the Projection type can be defined in the Texture Tag’s settings. To help position the material, switch to
If the wrong projection type or orientation is used, unwanted distortion or blurring can occur if the surface is angled too much. This can be compared to projecting a material onto a sphere using a slide projector. The surfaces facing the projector are positioned almost vertically to the projected image so they are textured correctly. The farther away the projected material is from these surfaces, the more distorted it will look because the angle of these surfaces to the projection increases accordingly. If the angle is large enough the texture may end up looking like a series of stripes on the surface. If no UV coordinates are available (or if they have not be prepared adequately in BodyPaint 3D) a projection type should be selected that best fits the shape of your objects - or at least its most important surfaces with regard to texturing.
When in Texture Axis mode the material itself can be moved, scaled or rotated using the respective tools in the top Icon Palette. Alternatively the Coordinate Manager or the values in the Texture Tag’s Coordinates (Attribute Manager) tab can be used to numerically change the projection’s Position, Scale or Rotate. These values can also be animated. This can be useful for animating clouds across the sky, for example. As you see, not every material effect has to be animated using only the material’s own settings.
Combining and Restricting Materials
Some objects require more than a single material, e.g., a label on a bottle or a logo placed somewhere. In Cinema 4D makes it is easy to assign multiple materials to a single object. This is done using a layer system in which materials higher in the hierarchy will "lie on top" of those below them. The hierarchical order is defined by the order in which the respective Texture Tags are placed in the Object Manager. The further to the right a Texture Tag lies the higher it lies in the hierarchy. If no material in the hierarchy contains an alpha channel, each material will cover the one below it.
The lower-lying materials can be made visible using one of the following methods: