How do you create a 3D sketch in modeling software?

Creating a 3D sketch in modeling software involves selecting the 3D Sketch tool and drawing geometry directly in three dimensions. This approach allows designers to define components or features that exist across all three axes (X, Y, and Z), which is essential for complex 3D modeling tasks.

In a 3D sketch, you can create lines, arcs, and splines that are not confined to a flat plane, enabling the development of more intricate shapes and better spatial relationships between different model elements. This technique is particularly useful for designing paths, controls, and other features that require depth and spatial accuracy.

The other options do not accurately represent the process of creating a 3D sketch. Rotating a 2D sketch would only result in a 3D appearance but does not involve actual 3D sketching. Applying textures to a surface relates to aesthetics rather than the structural creation of a model. Importing a 3D model pertains to bringing existing geometry into the software rather than creating new geometry via sketching. Thus, the selection and use of the 3D Sketch tool stands out as the correct method for initiating a 3D sketch in modeling software.