Neutral 3D CAD File Formats
Table of Content Features of 3D CAD file formats Different 3D CAD File Formats Various CAD file formats have been developed in recent years. If you’re seeking the most suitable 3D model file, you need to know about the different file formats available. There are many benefits and drawbacks to each format, and you should know which one is right for your needs. Upon completion, every CAD design/model is saved in a respective file format. A 3D file format stores information about 3D models in plain text or binary data. The 3D formats encode a model’s following characteristics: However, not every 3D CAD format stores each of the data mentioned above. Each software comes with its specific 3D file formats. The variety in CAD file formats pertains to many reasons such as cost, feature, etc. It is necessary for any two software to enable interchangeability/interoperability to make things work. Before we talk about that, let’s take a quick walk through the evolution of CAD file formats. Features of 3D CAD file formats Everything comes with its variety, and CAD modeling is no stranger. As the technology evolved, CAD modeling came up in different styles and formats. Three-dimensional model files are often stored in one of two formats: Native (.dwg) or Neutral (.dxf). Native files contain the most detail, while Neutral files skip elements and contain only a basic representation. While there are many CAD Neutral file formats, not all of them are created equal. Some file formats have exceptional capabilities or features, while others are less compatible. Some formats are standardized, while others are proprietary. Considering there are different file types, they will come with specific properties. Other file types allow CAD model viewing in different ways. Some CAD files are limited to only 2D viewing to show the end customer. But since we are talking about 3D CAD models, the following are the main features of 3D CAD file formats: Native or Neutral The two main types of file formats are – Native and Neutral. Native 3D CAD file formats: All CAD design software uses a proprietary file type. Native formats are those that are native to a specific CAD system. Generally, such file types can only be viewed using the same software it was created with. However, it won’t open in a completely different design program. Proprietary files could be used in intercompany tasks. By using native file formats, designers can ensure that their chosen components are compatible with their PLM software. Native files contain the most detailed representation of 3D CAD models. Some notable native 3D CAD file formats are AutoCAD, Parasolid, Inventor, NX, CATIA, Solidworks, etc. Neutral 3D CAD file formats: Neutral 3D CAD file formats are those that are not proprietary to a specific program or file format. These file formats are useful in transferring 3D data from one program to another but do not contain as much fine detail as native CAD files. Neutral files skip elements and include only a basic representation. Neutral CAD file formats ignore the elements that are unnecessary for the software to create the design. Since they are interoperable, they can be viewed on many programs. They are helpful for engineers and designers who need to communicate with other departments and share a single design. Moreover, Neutral formats are not as compatible with all 3D CAD software, and many users do not have the time or budget to learn each one. Neutral data come in handy if the document is distributed to end-users who don’t use CAD software. Precise or tessellated CAD designs are displayed in two ways, namely, precise or tessellated. The difference lies in the fact that the product viewed while designing looks quite different from the actual product in real life. It is particularly noticeable in the case of lines and edges that form the product shape. This differentiates between precise drawings versus tessellated drawings. CAD software uses precise lines and angles to complete complex manufacturing processes to create a product. Such specific instructions must be included in a file format to edit the actual drawing or change its design. The lines and edges are tessellated while displaying a CAD drawing for visual purposes. Type of assembly Multi-part designs present a complicated situation when choosing a file format. Depending on the type of file format, multi-part product design may be limited to one single file for the whole assembly. Alternatively, designers also opt for separate files for each component. Awareness of how a particular software will display a multi-part product or if it will display a multi-part product is essential. Parts Listings CAD designs generally come with a list of parts. Different formats have different ways of presenting this part list. Some file formats have a Bill of Materials (BOM), while others, called Flat Lists, show all parts one by one. A bill of material showcases a single part and all its positions in a drawing. The latter is better for presenting all parts of an assembly. Different 3D CAD File Formats If you plan on using the same tool for several different projects, make sure the CAD tool you’re using is compatible with the standardized formats. Otherwise, you could run into problems. Popular CAD file formats include DXF, DWF, STEP, and Solidworks. Neutral file formats are widely used nowadays as intermediate formats for converting between two proprietary formats to counter interoperability. Naturally, these two known examples of Neutral formats are STL (with a .STL extension) and COLLADA (with a .DAE extension). They are used to share models across CAD software. Neutral 3D CAD File Formats STL: STL, which stands for stereolithography, is the universal format for pure 3D information. It is used in 3D printers and is somewhat loved by CAM. STL denotes only the surface geometry of a 3D object without any representation of color, texture, or other common CAD model attributes. It is a common 3D printer file format. To optimize the file for 3D printing, you can use export settings and the Polygon Reduction tool. A stereolithography file format created by 3D Systems stores
Read MoreWhat is CAD | Types of CAD Models and CAD Formats
Table of content What is CAD? Types of CAD models Types of CAD formats Use of CAD What is CAD? Computer-Aided Design, aka CAD, is undoubtedly a crucial stage in product development. By definition, CAD is the acronym for Computer-Aided Design. It covers various design tools used by multiple professionals like artists, game designers, manufacturers, and design engineers. After a meshed part is aligned, it goes through surface modeling in tools such as Polyworks. It generates a non-parametric model (IGES or STEP format) or parametric modeling where a sketch of the meshed part is created instead of putting it through surfacing (.PRT format). The resultant is generally called a 3D computer-aided model or CAD model. The technology of CAD systems has tremendously helped users by performing thousands of complex geometrical calculations in the background without anyone dropping a sweat for it. CAD has its origin in early 2D drawings where one could draw objects using basic views: top, bottom, left, right, front, back, and the angled isometric view. 3D CAD programs allow users to take 2D pictures and convert them into a 3D object on the screen. In a simple definition, CAD design is converting primary design data into a more perceptible and more understandable design. Each CAD system has its algorithm for describing geometry mathematically and structurally. Types of CAD models. Everything comes with its variety, and CAD modeling is no stranger. As the technology evolved, CAD modeling came up in different styles. There are many methods of classifying them, but a broad general classification can be as follows: Two-dimensional or 2D CAD: The early version of CAD that most of us are aware of. These are 2-dimensional drawings on a flat sheet with dimensions, layouts, and other information needed to manufacture the object. The 2D CAD objects consist of lines, ovals, circles, ovals, curves, and slots. 2D CAD platforms generally come with a library of geometric images and the ability to create Bezier curves, polylines, and splines. They are also capable of generating a bill of materials (BOM). 2.5D CAD:The 2.5 D CAD are prismatic, which means they represent the depth of an object. They fall between 2D and 3D CAD, and the objects consist of geometric patterns like in 2D CAD. Three-dimensional or 3D CAD:The purpose of both 2D and 3D models is the same. But what sets 3D models apart is their ability to present more excellent details about the individual component and assembly by projecting it as a full-scale 3-dimensional object. 3D CAD offers a realistic portrayal of the CAD model. 3D models can be viewed and rotated in X, Y, or Z axes. It also shows how two objects can fit and operate, which is impossible with 2D CAD. 3D models can be further classified into three categories: 3D Wire-frame Models:These models resemble an entire object made of just wires, with the background visible through the skeletal structure. Surface Models:Surface models are the next stage of wireframe models, and they are created by joining the 3D surfaces together and look like real-life objects. Solid Models:They best represent real physical objects in a virtual environment. Unlike other models, solid models have weight, volume, and density properties. They are the most used models and serve as prototypes for engineering projects. The Boundary Representation (BREP) solid modeling links Constructive Solid Geometry (CSG) images while a hybrid systems mix CSG and BREP to attain the intended design. Types of CAD formats Different professionals use different software platforms for various reasons like cost, project requirements, features, etc. Although the software comes with its file formats, there are instances where one needs to share their project with someone else, either partners or clients, who are using different software. In such cases, it is necessary that both parties’ software understand each other’s file formats or, in other words, interoperable. As a result of this situation, it is essential to have file formats that can be accommodated in various software. CAD file formats can be broadly classified into two types: STEP: This is the most popular CAD file format of all. It is widely used and highly recommended as most software support STEP files. STEP is the acronym for Standard for the Exchange of Product Data. IGES: IGES is the acronym for Initial Graphics Exchange Specification. It is an old CAD file format that is vendor-neutral. IGES has fallen out lately since it lacks many features that newer file formats have. Parasolid: Parasolid was initially developed by Shape Data and is currently owned by Siemens PLM Software. STL: STL stands for Stereolithography which is the format for 3D information created by 3D systems. STL finds its usage mostly in 3D printers. STL describes only the outer structure or surface geometry of a physical object but doesn’t give out the color, texture, and other attributes of an object. VRML: VRML stands for Virtual Reality Modeling Language. Although it gives back more attributes than STL, a handful of software can read it. Prototyping & pilot runs (preliminary design stage) In this stage, prototypes are built and tested after several iterations, and a pilot run of the manufacturing process is conducted. This stage involves creating rapid prototypes for a concept deemed to have business relevance and value. Prototype means a ‘quick and dirty’ model rather than a refined one that will be tested and marketed later. Adjustments are carried out as required before finalizing the design. X3D: X3D is an XML-based file format for representing 3D computer graphics. COLLADA: COLLADA stands for Collaborative Design Activity and is mostly used in gaming and 3D modeling. DXF: DXF stands for Drawing Exchange Format, a pure 2D file format native to AutoCAD. Use of CAD CAD technology has placed the entire engineering process in an adrenaline mode. It is possible to mold or fold, modify, or make a new part from scratch, all with the help of CAD modeling software. The many uses of CAD are as follows:CAD generates design and layouts, details and calculations, and 3-D
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