Any 3D modeler that’s worked with engineering or architectural files knows the challenges for converting and optimizing CAD files for real-time visualizations like VR. Gary works in a 3D studio and helps develop VR and AR applications for different companies. He’s working on a new project – creating a VR simulation of a highly detailed robotic arm for an upcoming conference. The engineering CAD file of the robotic arm needs to be converted into polygon mesh and optimized for game engine development. Based on his experience, Gary knows that the CAD to VR content preparation pipeline is inefficient and time-consuming, and he wishes there was a better way to speed up CAD to VR data conversion and optimization.

The common pipeline of CAD design to VR visualization

Every 3D team or company has a unique pipeline for content development, but there are common practices that most 3D teams, like Gary’s, follow. The process begins when an engineering team exports their final model from their CAD design software to pass it on to the 3D team. The 3D team is in charge of converting the CAD file into polygon mesh using conversion software like Polytrans and Transmagic, or other 3D packages like 3ds Max. After the model is converted, the 3D team may either go directly into a game engine to create a visualization or into another 3D modeling program (Maya, Blender, Houdini, etc.) to do additional work, like texturing, adding materials, and UV mapping.

First hurdle: Conversion

The conversion process may sound simple on paper, but when you’re converting CAD files to a polygon mesh, the entire design is re-written in a new language. The problem is that the technical vocabularies between CAD and polygon mesh are incompatible, and therefore, metadata in the CAD file, including the connections between parts and names, are lost in the translation. The translation process also results in considerably larger file sizes, with many previously connected parts being separated or lost.

Let’s go back to our 3D modeler, Gary, that’s creating a VR visualization of a robotic arm to boost client engagement at an upcoming conference. He received a 500 MB STEP file from the engineering team. Using 3DS Max, Gary converted the STEP file into FBX, but to his surprise, the file quadrupled in size to 2GB. The file size wasn’t the only issue – the entire hierarchy of the robotic arm was broken, and the outliner was now made up of a giant list with multiple parents from each mesh. It was a nightmare to clean up and optimize.


Converting the robotic arm from CAD to polygon mesh significiantly increased file size and expanded the outliner. 

Second hurdle: Optimization

A combination of conversion issues, increased file complexity, and game engine limitations make CAD optimization necessary. The conversion process of going from CAD to meshcreated an expanded and messy outliner, increased file size, and separated small parts – fasteners like bolts and screws – that needed to be deleted because they were taking up unnecessary space in the visualization. At this point, Gary is starting to feel the pressure. He hasn’t even started creating the VR visualization for the client, and the deadline is fast-approaching.

Before being able to push the model into a game engine, there were a few tedious optimization tasks Gary needed to complete. First, Gary needed to organize the hierarchy because it was filled with empty nodes and multiple parents for each mesh. He also needed to optimize all the small parts – bolts and screws – found in the interior of the model. Although in SolidWorks these bolts and screws were connected in their metadata, all metadata was lost in the conversion, meaning Gary needed to individually delete all the thousands of bolts in the inside of the model. This is a tedious process – picture individually clicking and selecting each of the highlighted bolts below (and this is just a small section of the entire model).


The robotic arm model has a complex interior filled with small parts like bolts and screws. 

Gary knew he had to find a solution, luckily a fellow colleague suggested a 3D optimization software that could help him, and he was able to convert the STEP file into polygon mesh and optimize the model in a matter of minutes.

Bridging design to visualization with Meshmatic

Meshmatic, a 3D optimization software, is designed to optimize CAD files for VR and AR visualizations. While other software can convert from CAD to neutral file formats – like OBJ and FBX – Meshmatic does so in a way designed to work best with game engine development.

Now instead of going through the slow and inaccurate conversion and optimization process, Gary was able to import his STEP file into Meshmatic directly. Meshmatic analyzes the file and converts from CAD to a polygon mesh. Instead of using a third-party software to convert, you can use Meshmatic to convert and optimize your file, all in one go. Gary was able to easily fix the two main hurdles to optimizing his file –  the messy outliner, and large file size.

Using Meshmatic’s outliner optimization tool, Gary was able to organize the hierarchy in a matter of minutes. With just one click, empty nodes were removed and meshes with multiple parents were organized. Gary was also able to delete all the bolts and screws inside the model by using a tool that detects and groups parts based on volume size. After deleting the group of small parts that Meshmatic had detected, Gary’s file size went down by a whopping 54%! A testament to how important it is to delete unnecessary parts.

Once he finished optimizing, Gary easily exported the model directly into Unreal Engine (UE4). Importing into UE4 was a smooth process because the file size wasn’t bogging him down, and the outliner was nicely organized. He was able to focus on creating a high quality and accurate simulation for the client in less time, with much less effort. He even had time to sit back and enjoy a nice cup of warm coffee for a change. Well done Gary! 

A faster CAD to VR pipeline

For many 3D modelers like Gary, preparing CAD files for VR visualization is a lengthy process that’s slowed down because of inherent data conversion and optimization issues. Meshmatic provides a streamlined data preparation pipeline with smart automation tools and optimization algorithms that reduce file size while maintaining data accuracy. Instead of going from software to software to convert and optimize, you can use Meshmatic to complete the same steps all in the same software. With Meshmatic, 3D teams can be sure that they are delivering the best quality and most accurate visualization projects for the companies and clients they work with.

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