How to convert glTF
to Parasolid?

glTF is an open standard file format for 3D scenes and models. It's designed to be compact and efficient, making it easy to distribute and render 3D content on various platforms and devices.

glTF files contain information about the 3D scene, including geometry, materials, animations, and more. They can be used in different applications, from gaming and virtual reality to augmented reality and web-based 3D experiences.

Support of glTF in CAD Exchanger

CAD Exchanger can import and export glTF 2.0 files in binary (.glb) and text (.gltf) format. Such support includes:

• polygonal representations;
• assembly structure;
• names;
• colors, materials, textures;
• user-defined properties;
• PMI as polylines (export only).

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Pros of the format

Efficiency

All the basic data (vertices, triangles, normals, UV coordinates, etc.) are contained in binary form and can also be further compressed. Besides, the file structure is carefully organized to ensure that there is no extra or redundant data. Thus, the file contains only the necessary information to define the 3D scene, without any unnecessary clutter. By eliminating redundant data, glTF files become more lightweight and easier to process.

Cross-Platform Compatibility

It is an open standard supported by a wide range of platforms and applications. This allows for seamless integration between different software, making it easier to share and view 3D models across various devices. Whether it's a web browser, a virtual reality headset, or a mobile device, glTF ensures that your 3D content can be experienced on different platforms without any compatibility issues.

Cons of the format

Lack of Backward Compatibility

glTF has seen rapid development and improvements over the years, which means that older versions may not be fully compatible with newer software or engines. This can be a challenge if you are working with older files and need to use them in a newer environment.

Limited support of advanced features

For more advanced usage scenarios it may be important that this format has limitations in the areas of animation and lighting. In particular, there is inadequate support for keyframe animation with cubic interpolation, animation of rotation angles, and tension-continuity-bias animation curves. glTF also doesn't support lights and multiple attenuation models.

FAQ

What are the glTF file extensions?

glTF files typically have the extension ".gltf" or ".glb". The ".gltf" extension is used for the textual representation of the glTF file format. It is a human-readable JSON file that contains all the necessary information to define the 3D scene structure, including geometry, materials, animations, and more.

The ".glb" extension represents the binary version of the glTF format. It is a binary file that contains all the data, including the scene hierarchy, geometry, textures, and more, in a compact and optimized manner.

How to open an .glTF file?

To open this file, you will need a compatible software application, for example, CAD Exchanger Lab. Launch the software and navigate to the 'New file' option. Browse your computer's directories and locate the .gltf file you want to open. Then select it and click "Open". Once the import process is complete, the .obj file should be loaded into the software, allowing you to view and interact with the 3D model and associated data.

History of glTF format

This format was initially introduced by Khronos Group in 2015. The initiative aimed to create a common, royalty-free specification for efficient transmission of 3D content, with a focus on real-time applications and web delivery.

The first version, glTF 1.0, was released in 2015, providing a foundation for 3D asset transmission. Building upon the success of glTF 1.0, the Khronos Group released glTF 2.0 in 2017, which brought significant improvements and expanded capabilities. glTF 2.0 introduced a more efficient binary file format, enhanced support for physically-based materials, skeletal animations, and more advanced rendering features. It also introduced a clear separation between the JSON scene description and binary data, allowing for more efficient transmission and loading.

Since then, glTF has gained widespread adoption and support across the industry. Numerous software tools, engines, and platforms have embraced glTF as a standard for delivering 3D content. The format continues to evolve with regular updates and extensions, addressing new requirements and advancing the state of 3D content transmission.

Parasolid file format is native for Parasolid geometrical kernel, a widely used 3D geometric modeling kernel developed by Siemens PLM Software. This kernel provides a set of advanced tools and algorithms for creating, editing, and analyzing complex models. Like any kernel, Parasolid also has a persistence format known as Parasolid-XT. The Parasolid format refers to the file format used to store and exchange 3D geometry data created using Parasolid.

Support of Parasolid files in CAD Exchanger

CAD Exchanger can import files starting from v0.15 and up to v35 and export files from v12 to v35. Such support includes:

• B-Rep representations;
• assembly structure;
• names;
• user-defined properties;
• colors;
• layers.

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Pros of the format

Kernel nature

The primary advantage of Parasolid-XT lies in its kernel-based architecture. When you need to import data into CAD software running on the Parasolid kernel, opting for this format is a wise decision. As a kernel format, Parasolid-XT excels in its handling of B-Rep geometry, demonstrating exceptional proficiency in storing intricate B-Rep models encompassing solids, sheets, wireframes, mixed components, and even non-manifold topologies.

A notable advantage over the ACIS-SAT format is its capacity to represent the model hierarchy, albeit with some limitations (parts and bodies are somewhat synonymous). Nevertheless, in essence, the conversion to Parasolid-XT has the potential to preserve your part-assembly hierarchies, adding to its appeal as a preferred choice.

Representation of hybrid models

Another notable capability is the endorsement of hybrid models, specifically those in which a single logical component encompasses both B-Rep and mesh geometry. While this scenario currently represents a relatively small portion of real-world data exchange, it's gaining popularity. Consequently, the Parasolid kernel has been actively advancing to embrace these models, with the most recent iterations of the Parasolid-XT format designed to handle them.

Cons of the format

Proprietary nature

Parasolid is a proprietary format owned and developed by Siemens PLM Software. This means that the specifications of the format are not publicly available, and only licensed software developers can fully access and utilize the features of Parasolid. While many CAD software applications support the import and export of Parasolid files, the lack of public specifications can limit the ability to develop custom tools or work with the format outside of the licensed software ecosystem.

The lack of extensive metadata and visual attributes support

Parasolid-XT offers some support for metadata and visual attributes, including the ability to name entities, assign colors to shapes, utilize layers, and user-defined properties as key-value pairs. However, if you're dealing with multi-body parts, PMI, or advanced metadata, it might be more beneficial to consider using alternative formats like STEP or JT. These formats provide more extensive support for those specific requirements.

FAQ

What are the benefits of using Parasolid format?

The Parasolid format offers exceptional interoperability, and precise B-rep modeling ensures high geometric accuracy, making it suitable for complex engineering and design tasks. Its wide industry adoption makes it a trusted and standardized format, ensuring compatibility and long-term support.

Which industries use Parasolid format?

The Parasolid format finds extensive use in various industries due to its versatility and precision. Industries such as aerospace, automotive, manufacturing, consumer electronics, and medical devices all rely on Parasolid for 3D modeling and design. Its broad adoption across these sectors facilitates the development of everything from aircraft components and automotive designs to medical implants.

What are the primary Parasolid file extensions?

In Parasolid, two primary file extensions are commonly used. The first one is .x_t (Parasolid Text), which represents a text-based format. It stores 3D geometric data in a text format, allowing for easy interoperability between different CAD systems. The second extension is .x_b (Parasolid Binary), which represents a binary format. .x_b files contain the same geometric information as .x_t files but in a more compact and faster-to-process binary format.

History of Parasolid format

The Parasolid format, as a file format for storing 3D geometry, has its own history. Developed by Shape Data Limited in the 1980s, the Parasolid format was designed to enable the exchange of 3D solid models between different CAD systems.

In 1996, the company was acquired by Unigraphics Solutions Inc., which eventually became part of Siemens PLM Software. Since then, Parasolid has continued to evolve and adapt, keeping up with the ever-changing demands of the CAD industry.

With its powerful capabilities and efficient representation of 3D geometry, Parasolid quickly became a standard format for CAD software developers. Its widespread acceptance can be attributed to its seamless interoperability. Many leading CAD software applications, including Siemens NX, Solid Edge, and SolidWorks, incorporate Parasolid as their underlying kernel, allowing users to create, modify, and exchange complex 3D models with ease.

Over the years, Parasolid has played a vital role in various industries, such as automotive, aerospace, and consumer goods. Its precision and accuracy have made it an indispensable tool for designers and engineers, enabling them to tackle intricate designs and perform detailed analyses. Today, Parasolid remains a cornerstone in the CAD landscape, empowering professionals to bring their creative ideas to life in the virtual world.