Schlagwort: 3d modeling

  • 8 Most Common 3D File Formats – Simply Explained

    8 Most Common 3D File Formats – Simply Explained

    Reading Time: 24 minutes

    Which 3D file formats are there? How do they compare? What should you use? We simply explain the 8 most common 3D file formats used today: STL, OBJ, FBX, COLLADA, 3DS, IGES; STEP, and VRML/X3D.

    A 3D file format is used for storing information about 3D models. You may have heard of the most popular formats STL, OBJ, FBX, COLLADA etc. They are widely used in 3D printing, video games, movies, architecture, academia, medicine, engineering, and earth sciences. Each industry has its own popular 3D file formats for historical and practical reasons. We will learn about 3D file formats and take a deep dive into the 8 most common 3D file formats in this article.

    You can also jump to the most popular 3D file formats directly.

    What is a 3D File Format?

    A 3D model of a pigeon which contains color information, light sources (notice the shadow) and animations

    The basic purpose of a 3D file format is to store information about 3D models as plain text or binary data. In particular, they encode the 3D model’s geometry, appearance, scene, and animations.

    The geometry of a model describes its shape.  By appearance, we mean colors, textures, material type etc. The scene of a 3D model includes the position of light sources, cameras, and peripheral objects. Finally, animation defines how a 3D model moves.

    However, not all 3D file formats store all of this data. 3D file formats such as STL store only the 3D model’s geometry and ignores all other attributes. On the other hand, the format COLLADA stores everything.

    STL and COLLADA are just two of the many 3D file formats that people use. We estimate that there are hundreds of 3D file formats currently being used in the wild!

    How Many 3D File Formats are there?

    There are hundreds of 3D file formats
    There are hundreds of 3D file formats
    There are hundreds of 3D file formats

    The problem with 3D file formats is that there are literally hundreds of them. Every CAD software manufacturer such as AutoDesk and Blender has their own proprietary format which is optimized for their software. So if you use AutoCAD, you get a DWG file. If you use Blender, you get a BLEND file.

    Proprietary 3D File Formats Hinder Interoperability

    However, the presence of so many proprietary file formats is a big problem. Suppose you use AutoCAD (which is an AutoDesk product) and your friend uses Blender. Suppose that you also want to share your 3D model with your friend.

    This is not so easy. Your AutoCAD software gives you a DWG file because it is the native AutoCAD format. But your friend’s software, Blender, can only work with a BLEND file. This means that the two of you cannot work on the same 3D model.

    Neutral 3D File Formats Solve this Problem

    You often need to share your 3D models with your clients, collaborators and machines. Neutral formats are perfect for this task.
    You often need to share your 3D models with your clients, collaborators and machines. Neutral formats are perfect for this task.
    You often need to share your 3D models with your clients, collaborators and machines. Neutral formats are perfect for this task.

    To solve the problem of interoperability, neutral or open source formats were invented as intermediate formats for converting between two proprietary formats. Naturally, these formats have become hugely popular now.

    Two famous examples of neutral formats are STL (with a .STL extension) and COLLADA (with a .DAE extension).  They are widely used to share models across CAD software. If you want to share your 3D model, you convert the DWG file to a COLLADA file in a process called exporting and give your friend the COLLADA file. Your friend takes the COLLADA file and imports it into Blender, where the COLLADA file is converted to the native BLEND format. This way, you can continue to use different software and collaborate with others.

    Proprietary vs. neutral is one of the most important dichotomies in the world of 3D file formats. Nowadays, most 3D modeling software supports reading and writing popular neutral formats.  In addition, most software also support reading and writing to a subset of proprietary formats that are so popular that they cannot be ignored. We will discuss 8 such 3D file formats in this article. Here is the list, where the 3D file formats are marked with their type.

    3D file format Type
    STL Neutral
    OBJ ASCII variant is neutral, binary variant is proprietary
    FBX Proprietary
    COLLADA Neutral
    3DS Proprietary
    IGES Neutral
    STEP Neutral
    VRML/X3D Neutral

    But before we discuss each these formats in detail, we will first take a look at the general features of a 3D file format and discuss the important things you should keep in mind when selecting a format for your project.

    General Features of 3D File Formats

    As we discussed earlier, the general features of a 3D file format are:

    1. Encoding geometry of the 3D model
    2. Storing appearance of the 3D model
    3. Saving scene information
    4. Encoding animations

    1. 3D File Formats: Encoding Geometry of the 3D Model

    Every 3D model has a unique geometry and the capability of encoding this geometry can be considered to be the most basic feature of a 3D file format. Every 3D file format supports this — otherwise, they wouldn’t be considered 3D file formats.

    There are three distinct ways of encoding surface geometry, each with their corresponding strengths and weaknesses. They are called approximate mesh, precise mesh and constructive solid geometry (CSG).

    1.1 3D File Format Geometry: The Approximate Mesh

    The fine trinaglar mesh is approximately encoding the surface geometry of this 3D model (source : i.materialize)
    The fine trinaglar mesh is approximately encoding the surface geometry of this 3D model (source : i.materialize)
    The fine triangular mesh is approximately encoding the surface geometry of this 3D model (source: i.materialize)

    In this encoding, the surface of a 3D model is first covered with a mesh of tiny imaginary polygons. Triangles are most commonly used shape. The vertices of the covering triangles and the outward normal vector to the triangles are stored in the file. This represents the surface geometry of the target model.

    The vertices and the normal to each triangular facet making up the mesh is stored in the file.
    The vertices and the normal to each triangular facet making up the mesh is stored in the file.
    The vertices and the normal to each triangular facet making up the mesh is stored in the file.

    The process of covering a surface with non-overlapping geometric shapes is also known as “tessellation”. Hence these file formats are also called tessellated formats.

    The triangles approximate the smooth geometry of the surface. Hence this is an approximate format. The approximation gets better as the triangles get smaller. However, the smaller the triangles, the larger the number of triangles you need to tile the surface. This implies that the file needs to store a larger number of vertices and normal vectors. Thus better approximations come at the cost of increasing file size.

    The perfect spherical surface on the left is approximated by tessellations. The figure on the right uses big triangles, resulting in a coarse model. The figure on the center uses smaller triangles and achieves a smoother approximation (source: i.materialize)
    The perfect spherical surface on the left is approximated by tessellations. The figure on the right uses big triangles, resulting in a coarse model. The figure on the center uses smaller triangles and achieves a smoother approximation (source: i.materialize)
    The perfect spherical surface on the left is approximated by tessellations. The figure on the right uses big triangles, resulting in a coarse model. The figure on the center uses smaller triangles and achieves a smoother approximation (source: i.materialize)

    Approximate or tessellated formats are best used in situations where you don’t need ultrafine resolutions of the 3D model. A good example is 3D printing. 3D printers cannot print beyond a certain resolution and therefore, this type of 3D printing file formats are perfect for the job. In fact, the most popular 3D printing file format STL indeed belongs to this class of file formats.

    1.2 3D File Format Geometry 2: The Precise Mesh

    An example of NURBS patches encoding a curved surface geometry precisely. The red dots are the control points of the NURBS.
    An example of NURBS patches encoding a curved surface geometry precisely. The red dots are the control points of the NURBS.
    An example of NURBS patches encoding a curved surface geometry precisely. The red dots are the control points of the NURBS.

    There are, of course, situations where an approximate encoding of the 3D model is not enough and one needs precise encoding of the surface geometry. For example, when constructing the body of an airplane, in particular the round hull, a discrete polygonal mesh won’t work. Although the model might look good at small resolutions,  the flat faces and sharp corners will become apparent up close.

    Precise file formats get around this problem by using Non-Uniform Rational B-Spline patches (or NURBS) instead of polygons. These parametric surfaces are made up of a small number of weighted control points and a set of parameters called knots. From knots, a surface can be computed mathematically by smoothly interpolating over the control points.

    These surfaces look smooth in any scale and can replicate the surface geometry of a small part of a 3D model in exact detail. However, there’s always a trade off. While the precise mesh is exact at any resolution, they render slower and should be avoided in applications where speedy rendering is important.

    1.3 3D File Format Geometry 3: Constructive Solid Geometry aka CSG

    Finally, there’s yet another type of file format that does not involve meshes at all. In this format, 3D shapes are built by performing boolean operations (addition or subtraction) of primitive shapes like cubes, spheres etc. For example, to make a dumbbell, one can simply take two spheres and add a connecting cylindrical rod between. If you have ever used a CAD software, then you have seen this in action, because most of them use this principle.

    Constructive solid geometry in action during the construction of a dumbbell in Tinkercad
    Constructive solid geometry in action during the construction of a dumbbell in Tinkercad
    Constructive solid geometry in action during the construction of a dumbbell in Tinkercad

    Constructive solid geometry is great for designing 3D models and is very user-friendly. Another big advantage is that each individual editing step (addition, subtraction, transformations of primitive shapes) is stored in this 3D file format. Therefore, one can undo and redo any step at any time.

    Clearly, if you convert this format to a mesh-based format,  you will lose the information about the individual editing steps.

    2. 3D File Formats: Appearance

    The second important feature of 3D file formats is the ability to store appearance related information. In many applications, the appearance of the 3D model is of prime importance. For example, no one wants to play Need For Speed with dull, colorless cars. The cars better be colorful and shiny! The color and shine of a car are examples of appearance related properties. In simple terms, appearance describes surface properties such as material type, texture, color etc. This decides how the model looks like when it is rendered.

    Information about appearance can be encoded in two different ways.

    2.1 3D File Format Appearance: Texture mapping

    Illustration of how texture mapping is used to encode color and texture information of one side of a cube
    Illustration of how texture mapping is used to encode color and texture information of one side of a cube
    Illustration of how texture mapping is used to encode color and texture information of one side of a cube

    In texture mapping, every point in the 3D model’s surface (or the polygonal mesh)  is mapped to a 2-dimensional image. The coordinates of the 2D image have attributes like color and texture. When rendering the 3D model, every surface point is assigned a coordinate in this 2-dimensional image. The vertices of the mesh are mapped first. The other points are then assigned coordinates by interpolating between the coordinates of the vertices.

    Most 3D file formats support texture mapping. In this case, the 2D image containing texture information needs to be stored within the same file or separately in a different file.

    2.2 3D File Format Appearance: Face attributes

    Another common way of storing texture information is to assign each face of the mesh a set of attributes. Common attributes include color, texture and material type.

    In addition, a surface can have a specular component indicating the color and intensity of true mirror reflections of light sources and other nearby surfaces. Surfaces can be transparent or semi transparent. This is encoded by a transmissive component describing the color and intensity of light that passes through the surface. Transparent surfaces usually distort light passing through them. This distortion is represented by an index of refraction property, associated with the model’s material type.

    A transparent 3D model of a chair. The transparency is encoded as a property of each individual facet.
    A transparent 3D model of a chair. The transparency is encoded as a property of each individual facet.
    A transparent 3D model of a chair. The transparency is encoded as a property of each individual facet.

    3.3D File Formats: Scene information

    The capability of encoding information about the scene is another important feature of some 3D file formats. The scene describes the layout of the 3D model in terms of cameras, light sources, and other nearby 3D models.

    The camera is defined by four parameters: magnification and principal point, location, the direction the camera is facing and an arrow indicating which direction is “up”.

    The encoding of the light source depends on the nature of the light source. In the simplest case of a point source, we simply need to store the source’s location, its color, and its intensity.

    Some 3D file formats have the capability to encode information about lights, as shown in this image.
    Some 3D file formats have the capability to encode information about lights, as shown in this image.
    Some 3D file formats have the capability to encode information about lights, as shown in this image.

    The spatial relationship between the 3D model and other nearby models is also sometimes stored. This is particularly important if the model is made of several parts, which needs to be laid out in a certain way to make up the scene.

    It is worth noting that most 3D file formats often do not support scene information. This stems from practical reasons. When it comes to layout, one can always ensure that the parts of the model are placed in the correct location before saving the model. In this case, the file format does not need to explicitly define the relationships between the parts. The camera and light attributes can also be ignored since it is expected that the end users will change the camera position anyway as they navigate around a scene.

    4. 3D File Formats: Animation

    Some 3D file formats have the capability to store animations of a 3D model. This is very useful in game designing or movie making where animations are used heavily.

    4.1 3D File Format Animation: Skeletal animation

    The most popular way of animating a 3D model is called “skeletal animation”. In skeletal animation, each model is associated with an underlying skeleton. The skeleton is made out of a hierarchy of virtual “bones”. The movement of bones higher in the hierarchy (parent bones) affect the bones lower in the hierarchy (child bones). This is similar to the human body, where a movement of the shin bone affects the position of the toes.

    It is important to understand that these bones are not real bones, but merely mathematical constructs that help an animator define movements in a model. The bones are typically represented by a 4×3 matrix where the first three columns represent rotation, scale, and shear of the bone.  The last column is the translation relative to the parent’s world space.

    In addition to the transformation, each bone is given a unique ID and is associated with a subset of the mesh encoding the surface geometry. This subset moves along with the virtual bone.

    Bones are connected by “joints”. Joints introduce constraints in the possible transformations associated with a bone, thereby restricting how a bone can move in relation to its parent. This is again similar to the human body – the elbow may only rotate around a specified axis while the ball joint between the thigh and pelvis allow rotation around all axis.

    Here is a cool and short video explaining how bones and joints can be used to create basic animations in Cinema4D.

    4.2 3D File Format Animation: Techniques of animation

    There are many different techniques of storing animations of skeletal structures. The most important techniques are forward kinematics, inverse kinematics, and keyframes. You can read much more about animation techniques and encodings in this Bachelor thesis by Marcus Lundgren.

    Which 3D File Format Should you use for Exporting and Sharing your Model?

    We are now in good position to answer this question.

    Every 3D modeling software allows exporting into many different 3D file formats. However, which one you choose for your application depends a lot on which features you need for your work and the software you are going to use. Since we are now familiar with the different features of 3D file formats, we are ready to take an abstract look at the different considerations that goes behind the choice of a particular file format. There are three major considerations.

    1. 3D File Formats: Which Features do you Need?

    3D file formats are used in many different sectors and industries and each has their own specific needs and requirements. Depending on which industry you are in, you might want different sets of features in your ideal 3D file format. To explain what we mean, let’s discuss three major industries using 3D file formats.

    1.1 3D File Formats for 3D Printing

    The 3D printing industry uses approximate file formats. Capability for storing appearance is required in some cases.
    The 3D printing industry uses approximate file formats. Capability for storing appearance is required in some cases.
    The 3D printing industry uses approximate file formats. Capability for storing appearance is required in some cases.

    In 3D printing, high precision is not a requirement because the current printers cannot print beyond a certain resolution. Therefore, file formats using the approximate encoding of the surface geometry are ideal for the job. STL is such a file format and is the most popular 3D printing format to date.

    STL, however, cannot store information related to appearance. So if you want to print a multicolor model, then you can’t use STL anymore because it cannot store color or material related information. There are other file formats such as OBJ or AMF which can store appearance related information. Thus these formats (OBJ being the most popular) are the best choice for multi-color models.

    1.2 3D File Formats for Graphics Based Applications (Games and Movies)

    Games require fast rendering, support for rich color and textures, and animation.
    Games require fast rendering, support for rich color and textures, and animation.
    Games require fast rendering, support for rich color and textures, and animation.

    In graphics based applications, the requirements are different from 3D printing. Since we are way past the black and white era, 3D models used in games and movies require rich colors and texturing. Games and movies also need to support animation. In addition, all graphics based applications usually demand high rendering speeds. Therefore, the best formats for this kind of job would be something that uses approximate geometry to achieve fast rendering, can encode appearance and support animation. The FBX and COLLADA formats check all these boxes and hence are ideal for graphics applications.

    1.3 3D File Formats for High-Precision Engineering

    3D modeling in the area of aeronautics engineering requires precise encoding of surface geometry
    3D modeling in the area of aeronautics engineering requires precise encoding of surface geometry
    3D modeling in the area of aeronautics engineering requires precise encoding of surface geometry

    The name says it all. In the discipline of high precision engineering such as aerospace engineering, the 3D models need to be smooth and precise at any scale. Therefore, formats using precise geometry such as IGES or STEP are going to be the best fit for this task.

    Since the features of a 3D file format is a crucial consideration in identifying the ideal format, we have provided a table of features supported by the top 8 3D file formats in the appendix to this article. You can take a look at it when you need to make a decision.

    2. Which Software Pipeline are you Going to Use?

    The next important consideration is the software pipeline that you will use for your task. Not all software support importing and exporting of all 3D file formats. You should choose a file format that is supported by your software of choice.

    For your reference, we have included a table of file formats supported by the commonly used 3D modeling software and engines in the second appendix to the article. This is another resource you can consult when deciding on a file format.

    Market share of the most popular 3D modeling software
    Market share of the most popular 3D modeling software
    Market share of the most popular 3D modeling software

    3. Which Software does your collaborator use?

    The file format that you choose not only needs to fit into your pipeline, but also into your collaborator’s pipeline. If you know your collaborators, ask them what they use and discuss which file formats fits well into both your and your collaborator’s workflow.

    If you don’t know your collaborators, then it’s best to play it safe.  Just choose the most popular format that satisfies the previous requirements. It’s best if the format is neutral and not proprietary.

    Top 8 3D File Formats in Detail

    So far, we have discussed 3D file formats at an abstract and high level. We have discussed the different features that 3D file formats implement and how you can pick the ideal 3D file format based on this knowledge. Now, let’s take a look at the 8 most important 3D file formats and find out which of these features they support, how popular they are and which industries use them the most.

    If you are looking for information about a certain 3D file format, you can skip the others and jump right to that 3D file format.

    1. STL
    2. OBJ
    3. FBX
    4. COLLADA
    5. 3DS
    6. IGES
    7. STEP
    8. VRML and X3D

    3D Files Format #1: STL

    STL (STereoLithography) is one of the most important neutral 3D file formats in the domain of 3D printing, rapid prototyping, and computer aided manufacturing. It is native to the stereolithography CAD software made by 3D Systems. The corresponding file extension is .STL.

    STL is one of the oldest 3D file formats and was created in 1987 by Chuck Hull, who is currently the CTO at 3D Systems. He also invented the world’s first stereolithographic 3D printer. The STL file format was created subsequently as a simple way of transferring information about 3D CAD models to this 3D printer.

    Main characteristics

    STL encodes the surface geometry of a 3D model approximately using a triangular mesh. Since it was one of the first 3D file formats to exploit tessellations as a way of encoding surface geometry, it has several backronyms such as “Standard Tessellation Language” and “Standard Triangle Language”.

    STL ignores appearance, scene, and animations. It is one of the simplest and leanest 3D file formats available today. The STL format specifies both ASCII and binary representations. Binary files are more common since they are more compact.

    Popularity and future prospects

    Ever since its invention, the STL file format has been rapidly adopted by the rapid prototyping, 3D printing, and computer-aided manufacturing industries. It is still the most widely used file format in 3D printing.

    The reign of STL over 3D printing might end soon, however. In recent years, 3D printing technology has advanced rapidly. The fidelity of printing processes are now reaching micron level accuracy. Since STL is an approximate format, it needs very small triangular facets to reach this resolution, producing huge and unwieldy files in the process. Secondly, many 3D printers now allow printing in full color, a technology that’s expected to become more widespread in the near future. STL can’t encode color information and is useless for this purpose. For these reasons, the reign of STL over the 3D printing world may not last long and formats like OBJ, 3MF, or AMF might replace it.

    Which industries use it?

    3D printing, rapid prototyping, computer aided manufacturing. To know more about the STL file format, you can see our detailed article on STL.

    3D Files Format #2: OBJ

    The OBJ file format is another neutral heavyweight in the field of 3D printing. It is also widely used in 3D graphics. It was first developed by Wavefront Technologies for its Advanced Visualization animation package. The 3D file format has the extension .OBJ.

    Main characteristics

    The OBJ file format supports both approximate and precise encoding of surface geometry. When using the approximate encoding, it doesn’t restrict the surface mesh to triangular facets. If the user wants, he can use polygons like quadrilaterals. When using precise encoding, it uses smooth curves and surfaces such as NURBS.

    The OBJ format can encode color and texture information. This information is stored in a separate file with the extension .MTL (Material Template Library). It does not support any kind of animation. The format specifies both ASCII and binary encodings, but only the ASCII encoding is open source.

    Popularity and future prospects

    The OBJ file format, by virtue of being neutral or open, is one of the most popular interchange formats for 3D graphics. It is also gaining traction in the 3D printing industry as the industry moves towards full color printing.

    Which industries use it?

    3D graphics, 3D printing

    For more information on the OBJ file format, you can see its Wikipedia page.

    3D Files Format #3: FBX

    FBX is a proprietary file format which is widely used in the film industry and video games. It was originally developed by Kaydara but was bought by Autodesk in 2006. Ever since the acquisition, AutoDesk has used FBX as an interchange format for its own portfolio which includes AutoCAD, Fusion 360, Maya, 3DS Max and other software packages.

    Main characteristics

    The FBX file format supports geometry and appearance related properties like color and textures. It also supports skeletal animations and morphs. Both binary and ASCII files are supported.

    Popularity and future prospects

    FBX is one of the most popular choices for animation. In addition, it is also used as an exchange format which facilitates high fidelity exchange between 3DS Max, Maya, MotionBuilder, Mudbox and other proprietary software.

    Which industries use it?

    Video game industry and film industry. To know more about the FBX file format, you can see its Wikipedia page.

    3D Files Format #4: COLLADA

    Collada is a neutral file format used heavily in the video game and film industry. It is managed by the non-profit technology consortium, the Khronos Group. The file extension for the COLLADA format is .DAE.

    Main characteristics

    The COLLADA format supports geometry, appearance related properties like color, material, textures, and animation. In addition, it is one of the rare formats supporting kinematics and physics. The COLLADA format stores data using the XML markup language.

    Popularity and future prospects

    The original intention behind the COLLADA format was to become a standard among 3D file formats. Indeed, in 2013, it was adopted by ISO as a publicly available specification, ISO/PAS 17506. As a result of this history, lots of 3D modeling software support the COLLADA format.

    However, the consensus is that the COLLADA format hasn’t kept up with the times. The COLLADA format was once used heavily as an interchange format for Autodesk Max/Maya in the film industry, but the industry has now shifted more towards OBJ, FBX, and Alembic.

    Which industries use it?

    Film industry, video game industry. For more information about the COLLADA file format, see the official docs from the Khronos Group.

    3D Files Format #5: 3DS

    3DS is a proprietary file format used in architecture, engineering, education, and manufacturing. It is native to the old Autodesk 3D Studio DOS, a popular modeling software which was later replaced by its successor 3D Studio MAX in 1996. Developed in the 90s, it is one of the oldest 3D file formats. It has become one of the de facto industry standards for storing 3D models or for interchanging between two other proprietary formats.

    Main characteristics

    The 3DS file format retains only the most basic information about geometry, appearance, scene, and animation. It uses a triangular mesh to encode the surface geometry approximately, the total number of triangles being limited to 65536. It stores appearance related properties like color, texture, material, transmissivity etc. Scene information such camera position, lights can also be stored, but the format does not support directional light sources.

    The 3DS format specifies a binary encoding and stores information in chunks. This allows parsers to skip chunks they don’t recognize and allows for extensions to the format.

    Popularity and future prospects

    Being one of the oldest file formats, 3DS has become a standard for storing 3D models and interchanging between other 3D file formats. Virtually all 3D software packages support it. However, since this format retains only the most basic information about the 3D model, it cannot be used in situations where one does not want to lose information. In this case, this format needs to supplemented by the MAX format (now superseded by the PRJ format), which contains extra information specific to Autodesk 3DS Max, to allow a scene to be completely saved/loaded.

    Which industries use it?

    Architecture, engineering, education, and manufacturing. To know more about the 3DS file format, you can check out the Wikipedia page.

    3D Files Format #6: IGES

    IGES (pronounced eye-jess) is a neutral old timer used primarily in the defense industry and in the field of engineering. It was developed in the mid-seventies by the US Air Force.

    Back in those days, the Air Force used to waste a lot of time in the tedious process of sharing and converting data between proprietary systems used by its suppliers. The situation was especially bad with larger projects like aircraft carriers or missile delivery systems involving hundreds of suppliers. The IGES format was developed by the Air Force in partnership with Boeing and others in order to serve as an interchange format that can be shared across all CAD systems. Since the 80s, the US Department of Defense has required that all defense and weapons contracts use IGES as the standard file format. The file extension corresponding to the IGES format is .IGS or .IGES.

    Main characteristics

    The IGES format is an ASCII encoding that is extremely flexible when it comes to representing surface geometry. It has the ability to use circuit diagrams, wireframes, precise free-form surfaces or CSG for storing geometry related information. The format can also store colors but does not support material properties like textures, material type etc. Animation is also not supported.

    Popularity and future prospects

    IGES has enjoyed widespread popularity ever since it was invented in the 70s. It has been adopted as a national standard in many countries such as UK and Australia. Virtually all CAD software supports it.

    The IGES file format is no longer developed, and yet it is still widely used to transfer data between CAD, CAM, and CAE software programs. It is a popular choice for 3D modeling, creation of technical drawings, and product design. It has the reputation of being a good choice for amateurs in 3D; professional 3D artists now prefer its successor STEP.

    Which industries use it?

    Defense, engineering

    3D Files Format #7: STEP

    STEP (The Standard for the Exchange for Product Data) or ISO 10303 was developed as a successor of the IGES file format. It is widely used in engineering related fields like automotive and aeronautic engineering, building construction etc. The corresponding file format is .STP.

    The officially stated objective of developing STEP was to create a mechanism that is capable of describing product data throughout the life cycle of a product, independent from any particular system. However, due to the complexity and size of the original standard, it has been later broken down into smaller, modular specifications in four major releases.

    Main characteristics

    The STEP format supports all the features supported by the IGES format. In addition, it can also encode topology, geometrical tolerances, material properties like textures, material types, and other complex product data.

    Popularity and future prospects

    STEP, like IGES, is a popular format for interchange of data between CAD, CAM and CAE software programs. For compatibility, it is still advisable to use IGES as it is the more common format and more likely to work with the receiving party’s software. However, for use cases where one needs to transfer information related to the model’s appearance, tolerances of the parts etc., STEP is the right format.

    Which industries use it?

    Engineering e.g. automotive, aerospace, building construction etc.

    For more information, read this comparative discussion of the IGES and STEP formats.

    3D Files Format #8: VRML and X3D

    The last 3D file format we will discuss is VRML and X3D. VRML (pronounced vermal and having the file extension .WRL) stands for Virtual Reality Modeling Language. It is a 3D file format that was developed for the World Wide Web. It has been succeeded by X3D.

    The term VRML was first coined in a paper by Dave Raggett titled “Extending WWW to support Platform Independent Virtual Reality” submitted to the first First World Wide Web conference in 1994. It took three more years till a mature version of the format VRML97 was created and became an ISO standard.

    VRML97 was used in some personal homepages and 3D chatting sites such as “CyberTown”. However, the format failed to gain any significant adoption. In addition, VRML’s capabilities remained stagnant while realtime 3D graphics improved fast. Eventually, the VRML consortium changed its name to the Web3D Consortium and started developing the successor of the VRML format X3D, which was released in 2001.

    Main characteristics

    X3D is an XML based 3D file format. It supports all features of the VRML format along with some additions.

    The VRML format uses a polygonal mesh to encode surface geometry and can store appearance related information such as color, texture, transparency etc. The X3D format adds NURBS encoding of the surface geometry, the capability of storing scene related information and support for animation.

    Popularity and future prospects

    The goal of X3D is to become the standard 3D file format for the web. In particular, X3D applets can run within a browser and display content in 3D using the OpenGL 3D graphics technology. X3D was also designed to integrate seamlessly with HTML5 pages much like the SVG format for images. However, till date, the format has not received wide acceptance.

    Which industries use it?

    Internet and the web. For more information about the X3D format, read this guide from the Web3D Consortium.

    Conclusion

    We have learned quite a bit about 3D file formats in this article. We discussed how and why there are hundreds of formats and how they can be classified into two broad categories: proprietary and neutral. Next, we explored the most important features of a 3D file format and provided tips on how you can choose the ideal format for your application.  We wrapped up with a discussion of the 8 most important 3D file formats, focusing on their features, popularity and use cases. The appendix has a wealth of information about the compatibility of these 3D file formats with the most popular 3D modeling software and engines. It also has a table for comparative analysis of the feature sets of these 3D file formats.

    We hope you enjoyed this article. Share it with your friends who are interested in the world of 3D modeling, game development, special effects, engineering, architecture and 3D printing. If you have any question, opinion or feedback, please share it with us in the comment section.

    Appendix

    1. Feature matrix of the 8 most popular 3D file formats

    Green indicates supported, red indicated not supported
    File format Geometry Appearance Scene Animation
    Approximate mesh Precise mesh CSG Color Material Texture Camera Lights Relative positioning
    STL
    OBJ
    FBX
    COLLADA
    3DS
    IGES
    STEP
    X3D

    2. Import/Export support in popular 3D modeling software and engines

    STL OBJ FBX COLLADA 3DS IGES STEP VRML X3D
    Sketchup No Export Export Both Both None No Export No
    Solidworks Both Both No No Both Both Both Both No
    Fusion 360 Both Import Both No No Both Both No No
    AutoCAD No No Both No Import Both Import No No
    Blender Both Both Both Both Both No No Both Both
    Rhino Both Both Both Export Import Import Import Both Export
    Cinema4D Both Both Both Both Both Import No Both No
    Unity No Import Import Import Import No No No No

    License: The text of „8 Most Common 3D File Formats – Simply Explained“ by All3DP is licensed under a Creative Commons Attribution 4.0 International License.

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  • PlastiSketch Debuts Alternative 3D Modeling Method Using Vectors

    PlastiSketch Debuts Alternative 3D Modeling Method Using Vectors

    Reading Time: 2 minutes

    PlastiSketch offers a new method of 3D modeling that is an alternative to established tools. It is designed for those that want to create sculpted 3D objects, but lack the artistic finesse required by the likes of Zbrush and Blender.

    In explaining his new creation, PlastiSketch, Marcel Urbanek also describes his personal frustration with 3D sculpting software. “I am totally unable to produce acceptable artistic output”. However, as he thinks himself a skilled vector graphics artist, he decided to develop a tool that meets him in the middle — taking what he knows well (2D vectors), and interpolating to form a 3D object.

    Currently an in-browser app, Urbanek worked through several weekends to finish the prototype PlastiSketch. It is based on open-source  graphical plugins paperjs, threejs and others. The beta version of PlastiSketch is available online for free.

    Urbanek describes the concept as a “reverse-MRT for 3D objects“. To create a 3D design you draw vector graphics that each represent one slice of the 3D object. Depending on the complexity of the object you wish to design, this may vary between two (the minimum number) and, say, half a dozen. You then fine-tune the design by specifying the distance between the slices. A preview of the design is displayed on the right of the program.

    Make 3D Things From 2D Things

    Admittedly it takes a while to wrap the head around this new approach to 3D modeling. Though from this early on in a protoype state, PlastiSketch already seems to have all the makings of a popular tool for beginners.

    To save you from fiddling with hundreds of points, PlastiSketch lets adjust the smoothness and quality of the 3D design. When you are happy with your design you can save it as OBJ file for 3D printing or revision in other programs.

    At the time of writing PlastiSketch is in beta, and is freely accessible online for anyone to use. If at a future point PlastiSketch becomes a paid service, Urbanek has promised to offer a free version with a similar feature-set as the version that is online now.


    License: The text of „PlastiSketch Debuts Alternative 3D Modeling Method Using Vectors“ by All3DP is licensed under a Creative Commons Attribution 4.0 International License.

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  • Facebook Supports New Format for Interactive 3D Model Uploads

    Facebook Supports New Format for Interactive 3D Model Uploads

    Reading Time: 2 minutes

    You can now digitally sculpt a 3D model and upload it straight to Facebook to share with your friends. In addition, Facebook is now offering support for higher-quality glTF 2.0 files.

    Facebook introduced 3D posts in October last year, enabling users to upload interactive models for their network to enjoy.

    For next steps, the social media giant is adopting the 3D industry-standard glTF 2.0 file format, enabling the sharing of higher-quality content. The new file format means it’s possible to show textures, improved lighting, and more realistic renderings.

    Better yet, the company is also offering tools to make implementing 3D sharing from any website, 3D software or app possible.

    “People build communities by sharing things they care about — through photos, videos and, increasingly, more immersive media types,” explains Aykud Gönen on the Facebook for Developers blog.

    With the new 3D posts, users are able to interact with a digital model by moving their mouse. The models are instantly responsive and it’s possible to swivel the post around to view it from all angles.

    The demonstration below shows the process of uploading a 3D model to Facebook.

    Sharing High-Quality 3D Models with Friends

    To upload a 3D model, you need to use an app which supports the company’s new API. You can also share a link from a website that supports 3D sharing to the social media website. It’s also now possible to take the 3D posts to the company’s VR hangout rooms, Facebook Spaces.

    If you’ve designed a model you’d like to share, simply drag and drop the file from your desktop into Facebook. Or, if you create models in VR, you can share a model from the Oculus Medium web gallery.

    Have a 3D model which isn’t a gITF 2.0? You can use Facebook’s open source converters on GitHub. With glTF 2.0, 3D content retains its desired texture and it’s possible to choose a background color for the model too.

    The company explain in their blog post that the aim is to create a 3D ecosystem across platforms. This is proven with how Facebook’s new Graph API endpoints enable developers to create 3D apps or cameras which share to the company’s News Feed directly.

    Another goal is to make sharing AR and VR easier for people with mobile devices rather than limit it to those with an expensive headset.

    Source: Facebook for Developers


    facebook developer


    License: The text of „Facebook Supports New Format for Interactive 3D Model Uploads“ by All3DP is licensed under a Creative Commons Attribution 4.0 International License.

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  • HP Z 3D Camera Offers HP Sprout’s 3D Scanning Capabilities For a Fraction of the Price

    HP Z 3D Camera Offers HP Sprout’s 3D Scanning Capabilities For a Fraction of the Price

    Reading Time: 3 minutes

    At CES, HP released a new “Z 3D Camera” which offers the 3D scanning capabilities of the Sprout Pro PC in a portable camera accessory. It attaches to your computer monitor and can help you scan 3D items in no time.

    At CES 2018, HP Inc. has announced its new Z 3D Camera. The company thinks this 3D camera will “help reinvent creative workflows and spark spontaneous real-time sharing of documents and physical work product.”

    So, what’s special about it? HP’s Z 3D camera allows creators to capture in 3D without having to buy a specialized scanner. Up until now, HP has offered the Sprout Pro which has a unique 3D camera integrated into the computer.

    HP’s Sprout PCs made 3D scanning easier with a down-facing camera and a touch mat. However, the system costs over $3,000. Instead, HP has now taken the 3D scanner feature and turned it into a portable option which can be attached to most monitors. With the Z 3D Camera and the mat, the same 3D camera technology will cost just $599.

    To 3D scan an item, you simply rotate the object in your hands or position it underneath the camera on your desk.

    “The demand for 3D content has skyrocketed and 3D pros are constantly looking for new hardware and software innovations to increase their end-to-end productivity, from concepting to production… HP Z 3D Camera helps speed up modeling, reinvent the creative palette and protect the artistic point of view as more people enter the profession and workflows become increasingly automated,”  said Louis Kim, global head of Immersive Computing, Personal Systems, HP Inc.


    HP Z 3D Camera

    Highlights of the HP Z 3D Camera

    The company claims to have had CG artists, 3D designers, game developers, and digital fine artists in mind while developing the camera. It will be able to capture and digitize 3D objects, 2D documents, and live video, alike the Sprout Pro.

    But there are compromises. You’ll be losing some of the features of the Sprout Pro: There’s no included projection capability of the Sprout Pro, also multitouch is not available with HP’s Z 3D camera.

    HP explains that the Z 3D camera will minimize desktop space thanks to a unique design. Although the technology is slightly scaled down in terms of its lack of Touch Mat and light projector, it still includes a 3D depth-sensing camera and a 14.6MP 2D camera.

    It also uses a technology called SLAM (Simultaneous Localization and Mapping) to track, scan, and construct a 3D model in real time. The resulting high-resolution “computer-graphics-friendly” images and textures can then be used for 3D and VR applications.

    Anyone with Windows 10 will be able to export models to PowerPoint 3D, Paint 3D and Mixed Reality Viewer. HP is also making it easier to share captures or live videos of notes and sketches from your desktop and hope to offer a “more human experience”.

    HP Z 3D Camera will be available in March but only in the US. Check out the company’s website to keep up to date and find out more.

    Source: HP Press Release


    HP Z 3D Camera

    Website: LINK

  • Star Wars Models Made by Zortrax Machines

    Star Wars Models Made by Zortrax Machines

    Reading Time: 3 minutes

    A lot of work goes into creating Star Wars models like the U-Wing and the Resistance Bomber. For that, model maker Alexander Hutchings trusts Zortrax machines.

    Alexander Jay Hutchings is a model maker who’s worked on a number of Blockbuster films, such as Rogue One, the Force Awakens, and The Mummy. While most of his work is done by hand, for many intricate components, he relies on 3D printing:

    “Lots of grills, complex geometry. We would 3D print those whenever we couldn’t make the part by hand.”

    According to Hutchings, the creative process “all begins with the script”. Screenwriters’ descriptions of vehicles are passed to concept artists, who in turn produce sketches for perusal by the director.

    The most promising designs are ordered as models. That’s where Hutchings comes in.

    Spaceship models for Star Wars are typically generated at a scale of 1:24. Especially large ships are done at 1:48, “otherwise the thing would have to be massive.”

    Hutchings uses the Zortrax M200, and relies solely on the company’s proprietary printing material:

    “The reason is simple, Zortrax has tested them. From my perspective, if I would use a third-party material, and it would clog up the printer, the machine would go out of order for half a day. It’s half a day’s worth of work lost. I don’t have time for this.”

    Although he started by 3D printing with Z-ABS, Hutchings now works almost exclusively with Z-ULTRAT, due to its low warpage.


    Another of the Star Wars models: the U-Wing Fighter

    From Toy Soldiers to Star Wars Models

    Hutchings grew up playing with toy soldiers and rifles made of sticks in Kent, UK.

    Make believe turned into a passion with Air Force, Navy, and Army models, as well as Games Workshop Warhammer figurines. Even his friends would give him their miniatures to paint, knowing full well his talent.

    Yet the original inspiration for modeling, says Hutchings, comes from Star Wars: “It was probably The Return of the Jedi that truly made me look at models, saying wow, they’re really cool, for the first time.”

    Of course, one doesn’t begin a career working at Lucasfilm. After high school, Hutchings studied at the Kent Institute of Art & Design, now the University for the Creative Arts.

    His first job was to create architectural mock-ups, models which require extreme levels of detail. Hutchings comments:

    “We’re talking down to a millimeter precision. One mistake and you don’t get paid. Above all else, it teaches you discipline.”

    The hard work paid off when the model maker was given the opportunity to work in the production of The Edge of Tomorrow. There he connected with and impressed Neil Lamont, who was also involved in the art for Rogue One and Force Awakens.

    It was working on these films where he first started using 3D printing. He now regards it as an essential part of his work:

    “Some of my colleagues perceived the 3D printer as a machine that would take their jobs away,” says Hutchings. “It’s not a technology about to replace us. It’s a tool to make our work better.”

    Source: Zortrax


    The U-Wing Fighter, in all its glory

    Website: LINK

  • Amazing Technology That Can Extract 3D Objects from 2D Photos

    Amazing Technology That Can Extract 3D Objects from 2D Photos

    Reading Time: < 1 minute

    Always wanted to created real 3D models from flat 2D pictures? If so, then „3 Sweep“ is just for you. Users will not only be able to „just extract them, but then manipulate them, transform them, copy them, and move them around the image.“

    You get the feeling that this is still in its early developmental stages, so there are some visible limitations. But in terms of what it’s capable already, we’ve never seen anything like it.

    If Adobe doesn’t have their eye on these guys, they’re making a big mistake.

    Official Source: LINK