The Complete PRC/U3D to SolidWorks Conversion Guide

Geometry Compression Support:

PRC/U3D: Full support | SolidWorks: No support

Impact:

Geometry compression describes the process of compressing the representations of a 3D model's geometry, usually a triangle mesh. 3D geometry compression does not change the topology of a 3D model, but just changes the way that a 3D model and its 3D positions and related vertex data is stored. Geometry compression can be lossy (just like JPEG compression in image processing can be lossy, for example), in which case one might notice slight artifacts like variations in 3D vertex positions (compared to the uncompressed 3D model). However, such differences are often not noticeable. There are only very few standards for geometry compression, like glTF's support of Draco compression and similar extensions.

Texture Compression Support:

PRC/U3D: Partial support | SolidWorks: No support

PRC/U3D Notes:

Basic texture compression for document embedding

Impact:

Texture compression refers to a process of compressing 2D texture images for memory-efficient rendering (and sometimes for efficient transmission). The decompression of compressed texture data is therefore performed on-the-fly during rendering, so that it never has to be stored in unpacked form, but can be kept as-is in GPU memory. Formats supporting texture compression methods, such as the ones offered by glTF through KTX2 containers, therefore allow 3D models to use a smaller memory footprint on the client device during rendering. This can speed up rendering time, and also make it possible to store and use larger amounts of texture data than it would otherwise be possible.

Multiple UV Channels Support:

PRC/U3D: Full support | SolidWorks: Partial support

SolidWorks Notes:

Limited multi-UV support, primarily through appearances and materials for visualization rather than game development workflows.

Impact:

Multiple UV channels allow the optimized and sophisticated use of various 3D modeling features at once. For example, one can use one set of UVs and 2D texture data to model a tiling texture or procedural material, and another UV set to leverage a global lightmap or occlusion map of the 3D model. In this example, a combination of tiled texture (UV channel 1) and baked ambient occlusion map (UV channel 2) is used. Without support for this feature, one needs to either give up the tiling property (e.g., by using a tool like RapidPipline to bake a single texture atlas), or give up the ambient occlusion map, as only one UV channel will be usable.

Embedded Textures Support:

PRC/U3D: Full support | SolidWorks: Partial support

SolidWorks Notes:

Textures can be embedded in appearances but with limited format support compared to dedicated 3D graphics formats.

Impact:

Embedded textures allow the storage and exchange of an entire 3D model and its materials within a single file, by embedding the texture images directly into the 3D file (and not storing them as separate image files). Without support for this feature, textures have to be stored in separate image files, and referenced from the main 3D model file.

Vertex Colors Support:

PRC/U3D: Full support | SolidWorks: Partial support

SolidWorks Notes:

Limited vertex color support, mainly through part coloring and appearance assignments rather than per-vertex color data.

Impact:

Vertex colors allow the attachment of colors to each vertex of a 3D model. This can be useful in scenarios such as scientific visualization, or when converting/meshing data from a colored 3D point cloud, for example. On the polygonal surface connecting the vertices, the respective vertex colors are usually smoothly interpolated. In this example, different colors are attached to the different corners of a cube. Without support for this feature, the cube won't have any colors.

Skinned Animations Support:

PRC/U3D: Partial support | SolidWorks: No support

PRC/U3D Notes:

Basic skeletal animation support in U3D

Impact:

Skinned animations are commonly used for 3D character models in interactive applications, such as games or virtual worlds. They make it possible to easily animate the 3D model using a helper structure based on virtual bones, composing a virtual skeleton for animation control. In this example, a skinned animation is used to pose a 3D character. Without support for skinned animations, the 3D model will remain in its default pose, such as the default T-pose.

Morph Targets Support:

PRC/U3D: Partial support | SolidWorks: No support

PRC/U3D Notes:

Simple morphing capabilities

Impact:

Morph Targets, or "Blend Shapes", are commonly used to animate facial expressions and soft surfaces, for example cloth under a cloth simulation. They model various states of the animations with different vertex positions. In contrast to skinned animations, morph targets do not use any virtual bones, but work solely on the vertex data. In this example, a facial animation is achieved through morph targets. Without suport for this feature, in this example, the face will not show the animation.

Standardized Format Support:

PRC/U3D: Full support | SolidWorks: Partial support

SolidWorks Notes:

SolidWorks uses proprietary file formats, though it supports many industry-standard import/export formats like STEP, IGES, and others.

Impact:

Standardization plays a huge role in 3D model formats. With a format being standardized, every application will have a clear way of how to load or store data using this format. This makes it easier to re-use the 3D model across different applications, but also to make sure it will still be accessible and usable after a couple of years.