Step-by-Step Guide to Cutting Objects in 3D Modeling 

The ability to cut objects is a crucial skill that provides 3D artists, architects, engineers, and designers with the means to intricately shape, perfect, and metamorphose their digital creations with both precision and ingenuity. Whether you're in the process of crafting an awe-inspiring architectural marvel, sculpting characters that possess a lifelike quality for a video game, or engineering the prototype of a product, attaining expertise in the art of cutting within the realm of 3D modeling serves as the portal to unlocking limitless creative potential.

Cutting Objects in 3D Modeling

In 3D modeling, cutting objects refers to the process of dividing or removing parts of a 3D model to create new shapes, refine existing ones, or achieve specific design goals. This operation is fundamental to the modeling workflow and allows 3D artists and designers to manipulate digital objects with precision and creativity. Cutting objects can be visualized as using digital tools to "slice" or "carve" through a 3D model, much like a sculptor shaping clay or a carpenter cutting wood.

Benefits of Cutting Objects in 3D Modeling 

Here are some of the key advantages of cutting objects in 3D modeling:

• Precision and control: Cutting allows for precise and controlled modifications to 3D models. Designers can make specific cuts to achieve exact shapes, sizes, and angles, ensuring that their models meet their design specifications with accuracy.
• Complex geometry: Cutting enables the creation of complex and intricate shapes that would be challenging or time-consuming to model manually. This is especially useful for achieving organic and irregular forms.
• Refinement and detail: It allows for the refinement of models by smoothing edges, eliminating imperfections, and adding fine details. This is crucial for achieving a high level of realism in 3D models.
• Efficiency in design iteration: In the iterative design process, cutting objects makes it easier to experiment with different design variations. Designers can quickly make changes, test ideas, and refine their models without starting from scratch.
• Architectural precision: Architects use cutting to create openings, windows, doors, and other architectural details in 3D models of buildings. This precision is vital for visualizing and planning architectural projects.
• Character articulation: In character modeling, cutting allows for the articulation of limbs, facial features, and clothing. This results in characters that can be posed and animated realistically.
• Product Prototyping: In product design and engineering, cutting objects is essential for creating prototypes. It enables designers to adjust components, test fitments, and evaluate the functionality of a product before manufacturing.
• Non-destructive editing: Some 3D modeling software offers non-destructive cutting workflows. This means that changes made through cutting can be adjusted or undone without permanently altering the original model, providing flexibility in the design process.
• 3D Printing preparation: When preparing models for 3D printing, cutting is used to create printable sections or layers. This process ensures that complex models can be manufactured successfully.
• Optimized mesh topology: Cutting allows for the optimization of mesh topology. By adding or removing vertices, edges, and faces strategically, modelers can ensure that their 3D models have efficient geometry suitable for rendering or animation.

How To Cut Objects in SelfCAD

To illustrate how to cut designs, we will cut the Cylinder and sphere shown below. You can always drag and drop the various objects by selecting them in the 3D Shapes category on the toolbar.

Stitch and Scoop 

In this section, we are performing boolean operations. Note that the Cylinder protrudes from the sphere both on top and below as shown by the red arrow below:

To cut out the Cylinder, go to the Stitch and Scoop category and select Difference. Select the Cylinder (mesh_8):

When you finalize, you will observe that the cylinder has been cut off and a hole has been created on the sphere. 

Sometimes you want to create a hole that does not go through all the way to the bottom. In this case, use the Move tool on the toolbar, to move the cylinder up a bit by using the Gizmo. 

Then, go to the Stitch and Scoop category once again and select Difference. Select the Cylinder (mesh_8):

The cut created will leave the bottom face. So the hole does not run throughout the sphere:

Select and Delete 

You can also select faces and delete them to make a cut. Activate the Fcae selection and select the faces colored yellow:

Then hit the Delete option in your workspace or keyboard. You will observe a cut is made as shown below:

After making the cuts, you can modify your objects by adding thickness to them. To do this, simply go to the Modify category on the toolbar, and select the Add Thickness tool:

You can as well deform the object in many other ways. For example, you can select the top faces of the sphere and then Flatten the face by using the Flatten tool in the Deform category. 

Then after flattening the face, click delete to make the cut. 

Cut With Cube Selection

On the right panel, activate the Cube Selection tool. Then you can adjust the selection based on your preference using the settings that appear on the left panel:

After adjusting the selection, you can then delete the faces or polygons of interest. 

Cut With Profile

We create profiles using Sketches. In this case, we want to look at two scenarios.  In the 3D Shapes select a Cube. Then on the Drawing category, select the 3D Sketch > Rectangle. Drawing a sketch on the cube as shown below:

Select both objects and then go to the Modify category and select the Cut With Profile tool. 

You can then activate the Face Selection select the face that was created and delete it to make a cut:

You can as modify the object by using the Extrusion tool in the Modify category as shown below:

However, when dealing with a sphere, it will be a different process of cutting with the profile. This is because the cube was a plane, but the sphere is not. Let us have a look at how we can cut with a profile when it comes to sphere-like shapes. 

Go to the Drawing and select the 3D Sketch. In this case, switch from Plane mode to Objects mode. This helps you to draw a sketch on the object. Using the plane mode makes the drawing even inside the object. In this case, use the Circle to sketch on the sphere as shown below:

Then select the two objects. On the Modify category, select the Cut with Profile tool:

After finalizing the operation the cut is made. You can then select the faces in the cut and do with them as you wish. You can delete or even extrude.

Edit Details 

You can also use the Edit Details tool to make a cut. Select the cube go to the Modify category and select the Edit Details tool:

You can edit details by drawing or dragging the edges and making new edges as shown below:

 After adding the edges, that means new faces are created. You can then select the faces and delete or cut them as you wish. Using SelfCAD software makes the process simpler and easily understandable.  

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