Autodesk Revit

Autodesk Revit is a building information modeling software for architects, structural engineers, mechanical, electrical, and plumbing (MEP) engineers, and contractors. The original software was developed by Charles River Software, founded in 1997, renamed Revit Technology Corporation in 2000 and acquired by Autodesk in 2002. The software allows users to design a building and structure and its components in 3D Modeling, annotate the model with 2D drafting elements and access building information from the building model's database. Revit is 4D building information modeling (BIM) application capable with tools to plan and track various stages in the building's lifecycle, from concept to construction and later maintenance and/or demolition.

Features

Modeling

The Revit work environment allows users to manipulate whole buildings or assemblies (in the project environment) or individual 3D shapes (in the family editor environment). Modeling tools can be used with pre-made solid objects or imported geometric models. However, Revit is not a NURBS modeller and also lacks the ability to manipulate an object's individual polygons except on some specific object types such as roofs, slabs and terrain or in the massing environment.

Revit includes categories of objects ("families" in Revit terminology). These fall into three groups:

• System families, such as walls, floors, roofs, ceilings, major finishes and even furniture built inside a project
• Loadable families/components, which are built with primitives (extrusions, sweeps, etc.) separately from the project and loaded into a project for use
• In-place families, which are built in-situ within a project with the same toolset as loadable components

An experienced user can create realistic and accurate families ranging from furniture to lighting fixtures, as well as import existing models from other programs. Revit families can be created as parametric models with dimensions and properties. This lets users modify a given component by changing predefined parameters such as height, width or number in the case of an array. In this way a family defines a geometry that is controlled by parameters, each combination of parameters can be saved as a type, and each occurrence (instance in Revit) of a type can also contain further variations. For example, a swing door may be a Family. It may have types that describe different sizes and the actual building model has instances of those types placed in walls where instance-based parameters could specify the door hardware uniquely for each occurrence of the door.

Although Revit software comes with a range of families out of the box (OOTB), they are limited, so users may find a need to build their own families or buy them from online stores.

Because of copyright issues in project work, fully 3D-modeled Revit project models are rarely for sale. Indeed, as most projects are site-specific and bespoke, the demand for existing models is light anyway. However, new practices or students of Revit may want to refer to completed models. There are a few sources for these, including websites such as BIMGallery and GrabCad.

Multiuser collaboration

Since version 3.0 Revit enables multiple users to work on the same building model. The workflow is similar to the use of a version control system in software engineering, that allows multiple developers to reliably collaborate on a common code base. Each Revit user works on a local copy of the design, periodically checking in the work into the central repository. New user starts with creating a local copy of this repository. When a user starts modifying some building elements, these elements get automatically locked, preventing others from modifying them. The locks are maintained in the central repository. The elements stay locked until the "borrower" checks in her work and releases the locks. Patented technology called "worksharing" allows Revit to minimize the set of elements being locked while allowing change propagation engine to update as many elements as needed, including the elements that are not locked. Revit typically avoids merge conflicts during check-in.

In early Revit versions the central repository has been a folder on LAN. This option is still available and appropriate for co-located design team. Since 2013 Autodesk also offers hosted cloud-based central repositories for Revit as a service.

Rendering

When a user creates a building, model or any other kind of object in Revit, they may use Revit's rendering engine to make a more realistic image of what is otherwise a very diagrammatic model. The user accomplishes this either by using the premade model, wall, floor, etc., tools, or making their own models, walls, materials, etc. Since Revit's 2010 release, the software came with a plethora of predefined materials, each of which can be modified to the user's desires. The user can also begin with a "Generic" material. With this, the user can set the rotation, size, brightness and intensity of textures, gloss maps (also known as shine maps), transparency maps, reflection maps, oblique reflection maps, hole maps and bump maps, as well as leaving the map part out and just using the sliders for any one (or all or none) of the aforementioned features of textures.

Cloud-based rendering with the experimental plug-in dubbed Project Neon, located on Autodesk Labs is in the beta phases and allows for the user to render their images through their Autodesk account instead of locally through their own computers. Revit models may also be linked directly into Autodesk 3ds Max (release 2013 and later) for more advanced rendering and animation projects with much of their material and object information maintained.