In this post I demonstrate how to achieve improved performance in Fusion 360 when working with meshes or STL files, particularly those mesh files with very high polygon counts. This polygon reduction technique is not located within Fusion 360 itself, but rather a free tool hosted on a website.
I've also created a tutorial on YouTube that walks you through the entire process:
Fusion 360 Performance
Ever tried to import a high triangle mesh into Fusion 360? If so, you'll know how problematic it can be when it comes to performance. I'm running a high spec machine with a 24GB Nvidia RTX 3090 and it doesn't help the situation at all.
Why not just use Fusion 360's Mesh Reduction tool?
Of course, Fusion 360 has a mesh reduction tool built in. But what use is this tool if you can't import the mesh into Fusion 360 in the first place? Plus, it's still twenty times slower than the technique I'll show you here.
Fast-Quadric-Mesh-Simplification
The technique is called fast-quadric-mesh-simplification. This technique is fast, memory efficient, free, high quality and based on the quadric-based edge collapse mesh simplification method. Fast quadric mesh simplification uses a threshold to determine which triangles to delete, which avoids sorting but might lead to lesser quality. It is about 4x as fast as Meshlab and can simplify 2M -> 30k triangles in around 3.5 seconds.
No Installation Required - Use the Web Tool
While this tool has been developed as a local plug-in and command line tool, a Live Web Version has also been developed by Tiger Yuhao Huang. This is a great contribution because you can use the tool anywhere provided you have access to the internet.
The mesh reduction tool is self-explanatory, but I'll run you through an example anyway. You simply browse for your chosen STL/OBJ file and adjust this slider to your desired mesh reduction percentage.
Fast Quadric Mesh Reduction Example
For this example I'll be using a 3D Relief Model from Turbosquid:
Input: 1,000,000 Verticies, 2,000,000 Triangles - 97.66MB
This model is very detailed, hence the high triangle count. If you zoom into the image below you can see all the triangles.
After uploading your chosen file to the mesh simplification tool you'll see a process log:
Output: 50,000 Verticies, 100,000 Triangles - 4.88MB
As seen in the process log above, the quadric mesh simplification tool simplified the model down to 5% of its original size. An example of the output file has been shown below:
How Significant is Detail Loss?
Ultimately, mesh reduction does come at a cost which is a loss of detail. However, the example above demonstrates that this loss is very minimal to the human eye. For typical CNC applications such as 3D Printing or Milling an extreme level of detail is unnecessary. It is outweighed by the fact that it causes your CAD/CAM workflow to be slower.
I actually went on to carve this reduced model into wood and the outcome was impressive.
Conclusion
This technique solved a lot of problems for me. I am now able to import what would have been an overly complex mesh into Fusion 360 and modify it. I am also able to generate CAM toolpaths a lot faster due to a 95% reduction in processing. Overall, I would say this is an essential tool to add to your arsenal if you work with high poly meshes frequently.
Thanks for Reading!
As always, thank you for reading. I hope you learned something. Be sure to subcribe to my YouTube channel for more great tutorials and CNC related content.
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