The Complete PRC/U3D to glTF Conversion Guide
Table of Contents
- General Information
- Converting and Optimizing PRC/U3D Files to glTF
- What are PRC/U3D and glTF files commonly used for?
- Comparison of Features Supported by PRC/U3D and glTF
- Limitations of PRC/U3D Files to glTF Conversion Workflow
- What's the best way to get PRC/U3D files into my 3D applications, and are there alternatives to using glTF?
General Information
This guide is part of the RapidPipeline 3D Formats Knowledge Database. It shows how to convert PRC/U3D to glTF, if you'd like to know more about the formats, please check out the following links:
Converting and Optimizing PRC/U3D Files to glTF
There are various ways to convert between PRC/U3D and glTF. With RapidPipeline, you can easily convert and and optimize PRC/U3D files, at scale. It supports glTF, as well as many other file formats (examples: FBX, OBJ, PLY, STL, USD, USDZ, VRM), at high quality.
Below you can find a video explaining how to convert your files:
Comparison of Features Supported by PRC/U3D and glTF
| Feature | Supported by PRC/U3D | Supported by glTF |
|---|---|---|
| Morph Targets | Partial0 | Yes |
| Rigid Animations | Yes | Yes |
| Skinned Animations | Partial1 | Yes |
| Animations | Yes | Yes |
| Free-Form Surfaces | Yes | No |
| Geometry Compression | Yes | Yes |
| Quad Meshes | Yes | No |
| Basic 3D Geometry | Yes | Yes |
| PBR Materials | No | Yes |
| Transparent Materials | Yes | Yes |
| Vertex Colors | Yes | Yes |
| Materials | Yes | Yes |
| Scene Composition | Yes | No |
| Hierarchical Scene Graph | Yes | Yes |
| Scene Nodes | Yes | Yes |
| Standardized Format | Yes | Yes |
| Embedded Textures | Yes | Yes |
| Multiple UV Channels | Yes | Yes |
| Normal Mapping | Partial2 | Yes |
| Procedural Textures | No | No |
| Texture Compression | Partial3 | Yes |
| Texture Transforms | Yes | Yes |
| Texturing | Yes | Yes |
Limitations of PRC/U3D Files to glTF Conversion Workflow
The following limitations should be taken into account when converting PRC/U3D files to glTF format:
| PRC/U3D Feature (not supported by glTF) | Limitation Details |
|---|---|
| Free-Form Surfaces | Free-Form Surfaces Support: PRC/U3D: Full support | glTF: No support   Impact: Free-form surfaces allow a CAD user to design surfaces with advanced controls over curvature and continuitiy. While these surfaces are common for CAD models (in the form of so-called boundary representations or "B-reps"), they need to be converted to polygonal triangle or quad data to work with most 3D rendering engines - a process called tessellation. In this example, a surface patch is used to describe a part of a curved surface of a product. Without support for this feature, the free-form surface has to be tessellated into quads or triangles. |
| Quad Meshes | Quad Meshes Support: PRC/U3D: Full support | glTF: No support   Impact: Quad meshes are a common way to hand-model and edit 3D models. 3D artists get intuitive control and such meshes are also easy to refine, as well as well-suited for creation of skinned animations. However, real-time rendering pipelines and hardware are usually all based on triangles, so if a 3D model should not be edited any more, it is safe to convert quads to triangles (and engines will do this automatically before sending data to the rendering hardware). In this example, a part of a mesh is modeled with quads. Without support for this feature, quads will have to be triangulated, producing a pure triangle mesh. |
| Scene Composition | Scene Composition Support: PRC/U3D: Full support | glTF: No support   Impact: Scene Composition describes the process of composing a scene through links from a main scene that pull in various other scenes/3D models. This can also happen in a nested fashion (through multiple levels of linkage). With a target format not supporting this feature, references to external models must be resolved and the content be baked into one 3D model, which is then saved in that target format. |
What's the best way to get PRC/U3D files into my 3D applications, and are there alternatives to using glTF?
Doing 3D conversion right, especially at scale, can be tricky, as 3D data is in general a rather complex (yet very powerful!) medium. This also applies to PRC/U3D and glTF files - the conversion guide above provides a rough first idea about that. Once you know what you would like to do, tools like RapidPipeline can help you perform the necessary steps, and to even automate the process for thousands or even millions of files.
Especially when introducing pipelines and workflows at scale in an enterprise context, it is usually good to rely on dedicated tools and expertise, making sure you do not introduce any steps into your 3D workflow that are detrimental to the final output's quality, or that take your team too much time (and money).
If you're interested to hire dedicated expertise from the best in the field to help your company reach your goals fast and reliably, please do not hestitate to contact DGG. Being the creators of RapidPipeline, and ambassadors for open 3D standards for more than a decade, we have been building some of the world's most advanced 3D pipelines, having processed many millions of 3D assets.
Therefore, our expertise will help you to reach your goals faster, at scale, and with the least possible friction, since we are focused on maximum interoperability.
To get started with 3D data conversion and optimization today, sign up for a free account!
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