Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D
As you already know, Camera Mapping is one of the most important projection types. With Camera Mapping, materials are projected onto objects from the angle of view of the camera. Since each subsequent modification to the camera can result in the material shifting on the object, the cameras are used for purposes other than intended. This is why at least one additional camera is required in the scene for creating fly-by animations or rendering the scene from a different angle.
There are basically two techniques with which Camera Mapping can be completed. You can either use an image as a template to re-create its motif, including its perspective, or you can create a rough model of the scene and subsequently project an image onto it. Projection Man is especially well-suited for the latter method. The Projection Man dialog window can be opened by selecting Projection Man from Cinema 4D’s menu. The basic procedure for using Projection Man is described below (a detailed workflow description, including an example, can be found in the Projection Man quickstart manual):
- Model a scene and position at least one Camera so it offers a good overall view of the scene.
- Select Projection Man... from the menu to open the Projection Man dialog window, in which all scene cameras and objects are listed.
- Select all objects in the Projection Man window to which a material should be applied using one of the scene cameras. Drag the selected objects onto the respective camera in the Projection Man dialog window. You will be asked if an existing bitmap texture should be loaded or if a new one should be created. If a new texture should be created, a new dialog window will open in which you can define the name, size and background color of the bitmap image.
- These parameters can be defined in the Preferences... menu, which can be opened from the main Cinema 4D menu. As you can see in the image below, there is also an option for selecting Default Channels. Here you can select which bitmaps and channels should automatically be used for the camera projection. The Alpha and Luminance channels are selected by default and ensure that the projected texture looks exactly like it should on the object and does not react to light sources.
- After the name, size and color of the new bitmap has been defined in the Projection Man dialog window you will be asked if the same material should be applied to all objects or if each object should be given its own texture (see image below). Depending on the variation selected, one or several materials, including bitmaps, will be created and applied to the objects. A new connection between the objects and the camera (in the form of Texture Tags in the Object Manager) will be established through the activation of Camera Mapping.
- The actual rendering of the textures is initiated by right-clicking on the camera in the Projection Man dialog window and selecting the Coverage Render command. If options for displaying texture edges were activated in the render settings, a simplified depiction of the objects as seen by the camera will be generated. This bitmap can be modified in BodyPaint 3D or Photoshop, etc. The connection that was established between the camera and the material will ensure that the modified bitmap will automatically fit perfectly onto the object.
Only objects and their respective surfaces that are seen by the camera will be textured. Hence, additional cameras may be required when mapping more complex scenes. Furthermore, distortions typical of Flat projections will be magnified if the position of the camera used for rendering differs too much from the position of the camera used for projection. Generally speaking, this type of projection is better-suited for use with objects that lie somewhat farther away from the camera used for rendering, e.g., a textured skyline. When using high-res textures, the detail on the objects onto which they are projected can be reduces accordingly.