Why is lemsip banned

Overview

The question of converting an NWD (Navisworks Cache File) to an RVT (Revit Project File) is a common one in the Architecture, Engineering, and Construction (AEC) industry. Professionals often find themselves with NWD files for project review, clash detection, and visualization, but then need to incorporate or rebuild that information within a native Revit environment. It's crucial to understand that NWD and RVT files serve fundamentally different purposes. An NWD is essentially a static, aggregated snapshot of a project, compiled from various sources like Revit, AutoCAD, and others, optimized for efficient viewing and coordination. It's a read-only format designed for the Navisworks platform. In contrast, an RVT file is the heart of a Revit project, containing intelligent building components, parametric relationships, and all the data necessary for BIM authoring, documentation, and analysis.

Because of these distinct functionalities and data structures, a direct, lossless conversion from NWD to RVT is not natively supported by Autodesk software. Think of it like trying to convert a detailed architectural rendering (NWD) back into the original CAD drawings and 3D modeling files (RVT) that were used to create it. While you can extract geometric information and potentially some metadata, the underlying intelligence and parametric nature of the Revit model are lost in the aggregation process of the NWD. Therefore, any workflow aiming to get NWD data into a usable RVT format involves intermediate steps, data translation, and often a significant amount of manual effort to reconstruct the model's intelligence.

How It Works

The process of getting NWD data into a Revit environment typically involves extracting information from the NWD file and then importing or linking that information into a Revit project. This is not a direct conversion but rather a reconstruction or re-authoring effort.

• Exporting Geometry and Data: The first step often involves exporting the geometry from the NWD file into a format that Revit can import. Navisworks allows exporting to various formats, including DWG (for 2D linework or basic 3D solids), IFC (Industry Foundation Classes – a BIM interoperability standard), or even point clouds. The choice of export format depends on what type of information you aim to retain and how you intend to use it in Revit. For example, exporting to DWG might be useful for tracing over or using as underlays, while IFC aims to preserve some BIM data, though its fidelity can vary significantly based on the source model and export settings.
• Linking or Importing into Revit: Once the data is exported, it can be brought into Revit. Linked files (e.g., linking a DWG or IFC) allow the geometry to be present in the Revit model but remain external, meaning changes to the source file can be updated in Revit. Importing the file directly embeds the geometry into the Revit project. For IFC, Revit can import it as native Revit elements if the IFC model was exported with sufficient BIM information and the import settings are configured correctly. This is the closest one might get to retaining some level of intelligence, but it's often imperfect.
• Re-modeling or Ghosting: In many scenarios, especially when the goal is to create a fully functional BIM model in Revit, the imported or linked geometry from the NWD serves as a reference. Users will then proceed to model new, intelligent Revit elements (walls, doors, windows, structural components) based on the geometry of the NWD. This is often referred to as 'ghosting' or 're-modeling.' The original NWD geometry acts as a visual guide or a placeholder for new Revit families and components to be built around.
• Utilizing Third-Party Tools: While Autodesk's native tools provide the basic framework, specialized third-party plugins and conversion services exist that claim to offer more sophisticated conversion capabilities. These tools sometimes attempt to interpret the aggregated geometry and metadata from NWD files and translate it into more intelligent Revit components. However, the success of these tools can be highly dependent on the complexity and origin of the NWD file, and they often come with their own limitations and costs.

Key Comparisons

Why It Matters

The ability to leverage information from NWD files within a Revit environment is critical for several reasons, primarily related to project lifecycle management and the effective use of BIM data.

• Seamless Project Handover and Reconstruction: Often, a project might be reviewed and coordinated extensively in Navisworks, resulting in an NWD file. If the original source files are lost or if a new team takes over, the NWD can serve as a valuable reference for reconstructing the project in Revit. This prevents the need to start entirely from scratch and ensures continuity.
• Facilitating Facility Management and Operations: While an NWD file can be used for basic visualization in facility management, a true RVT model provides much richer data for asset management, maintenance scheduling, and operational analysis. Being able to translate or rebuild from an NWD into an RVT allows for the creation of a 'digital twin' that is far more useful for the building's operational phase.
• Enhancing Design Development and Documentation: If an NWD file contains design decisions or coordination outcomes that need to be incorporated into the active design, having a pathway to Revit is essential. This allows designers and engineers to update their models, generate new documentation, and perform further analysis based on the reviewed information, ensuring the project progresses efficiently and accurately.

In conclusion, while a direct NWD to RVT conversion is not a reality, understanding the workflows for data extraction and re-modeling makes it possible to leverage the valuable coordination and review information contained within NWD files to create or update robust and intelligent BIM models in Revit. This process is fundamental to efficient project delivery and effective lifecycle management in the AEC industry.