Cinema 4D is one of the most powerful 3D modeling and animations packages on the market. It has been used in an enormous number of movies, televisions series, commercials and video games. The modeling tools in Cinema 4D compare favorably with its two main competitors, Maya and 3D Max. One of the most useful; tools in Cinema 4D is the knife tool. The knife tool allows users to divide models directly without resorting to Boolean operations (which usually result in very poor quality 3D meshes). Using this tool on a model is a relatively straightforward process.
1. Open Cinema 4D. Select “File” from the menu and click “Open.” In the dialog box, browse to the model you have saved that you want to work with and open it.
2. Use the “Pan,” “Rotate” and “Zoom” functions at the upper right corner of the viewer to view the section of the model to which you want to apply the “Knife” tool.
3. Select “Polygon” selection mode from the panel on the left, then select the object and click on the “Make Editable” icon (if it is not on already). Turn on “Live Selection” in the tools and set the “Radius” to 1.
4. Click on “Structure” in the menu and select the “Knife.” In “Attributes” turn on “Restrict to Selection.”
5. Hold down the mouse and draw over the polygon faces to cut them. This creates multiple faces from the ones you had before. You can now delete these extra faces if you want to do things like add doors, windows or other openings.
6. Select “File” and click “Save” to save your changes. Or, if you would like to save the original file, select “File” and click “Save As.” In the dialog box, rename the file and save it.