What is a three-dimensional representation of an object used to test ideas called?

A three-dimensional representation of an object used to test ideas is typically referred to as a model. This term encompasses various types of representations, which can be physical or virtual. In engineering design, models are crucial for conceptualizing and refining ideas, allowing designers to visualize their designs more effectively. They can help in understanding spatial relationships and the functionality of different parts of a design.

In this context, the term "model" is broad and includes prototypes, which are built to test specific functionalities and features, as well as scale models, which are often used to represent something at a smaller scale for visualization purposes. A model in engineering design provides more detail and realism than a 2D drawing, making it suited for testing and evaluating ideas through simulation or physical interaction.