Book excerpt: The Autodesk(R) Inventor(R) 2021: Advanced Assembly Modeling guide builds on the skills acquired in the Autodesk Inventor 2021: Introduction to Solid Modeling and Autodesk Inventor 2021: Advanced Part Modeling guides to take you to a higher level of productivity when creating and working with assemblies. You begin by focusing on the Top-Down Design workflow. You learn how tools are used to achieve this workflow using Derive, Multi-Body Design, and Layouts. Other topics include model simplification tools, Positional and Level of Detail Representations, iMates and iAssemblies, Frame Generator, Design Accelerator, and file management and duplication techniques. A chapter has also been included about the Autodesk(R) Inventor(R) Studio to teach you how to render, produce, and animate realistic images. Topics Covered Applying motion to existing assembly constraints using Motion and Transitional Constraints. Introduction of the Top-Down Design technique for creating assemblies and its components. Tools for Top-Down Design, such as associative links, adaptive parts, multi-body and layout design, derived components, and skeleton models. Creating Positional Representations to review motion, evaluate the position of assembly components, or document an assembly in a drawing. Using Shrinkwrap and other model simplification tools to create a part model that represents an overall assembly. Creating Level of Detail Representations to reduce the clutter of large assemblies, reduce retrieval times, and substituting models. Using the Design Accelerator to easily insert standard and customizable components and features into your model. Creating rendered realistic images and animations of parts and assemblies using Autodesk Inventor Studio and the Video Producer. Prerequisites Access to the 2021.0 version of the software, to ensure compatibility with this guide. Future software updates that are released by Autodesk may include changes that are not reflected in this guide. The practices and files included with this guide are not compatible with prior versions (e.g., 2020). The class assumes mastery of Autodesk Inventor basics as taught in Autodesk(R) Inventor(R) Introduction to Solid Modeling. In addition, Autodesk(R) Inventor(R) Advanced Part Modeling knowledge is recommended. The use of Microsoft(R) Excel is required for this training course.