What distinguishes direct additive manufacturing from indirect additive manufacturing?

Direct additive manufacturing is characterized by its ability to create finished parts directly from digital 3D models. This method involves layer-by-layer material deposition to build a part as specified in a computer-aided design (CAD) file. In contrast, indirect additive manufacturing involves an intermediary step where molds or patterns are created from the digital design. These molds or patterns are then used to produce the final components, often utilizing traditional manufacturing methods.

This fundamental distinction makes option B the correct answer. Direct additive manufacturing offers the advantage of creating complex geometries without the need for molds, while indirect methods can limit design flexibility and increase processing time due to the extra steps involved.