CAD Files and Rendering and Engineers! Oh MY!

In the Spring of 2022, I collaborated with Peter Bohn of our Engineering Department. The department had shifted into what they call a "Design-based" curriculum; and as such, they had a group of around 15 freshman mechanical and electrical engineers take a CAD class with Autodesk Fusion.

I recognized that these types of CAD models represent distinct challenges when rendering. The parametric surfaces that Fusion uses to be able to adjust the models after the fact are difficult to convert to renderable geometry. Well, actually, they are quite easy to convert, it's just that they convert to disorganized and distorted triangles.

I thought their efforts would make an interesting challenge for my Junior level animators who were taking MART 363 Animation Rendering and had just finished a unit on Arnold's procedural texturing capabilities. The results can be seen in the movie below:

The first three models are actually Fusion files (exported to .fbx files) that I created while the rest are widgets modeled by the ENGR 112 Engineering Design and Fabrication class. We set up the files and let them using Arnold's area lights as well as HDR Sky Dome images we downloaded form Polyhaven.com.

I gave my students one example that I created while we waited for the engineers to complete their widgets. We talked about ways of lighting and texturing, and in some cases where the triangles were too distorted, we had to take the models into ZBrush to retopologize them.

Rendering was an interesting challenge too in that we had to look very carefully at the specular reflections as Maya's default sampling values are far too low. We discussed the necessity of balancing render times with looking good in the final render.

Interestingly, that particular class of engineers produced an interesting product. They designed an LED flashlight that they produced in a small production quantity of 90 units. An example can be seen below:

They printed 90 copies of the casing on our Lulzbot TAZ 6 FDM printers in PLA filament. The LED holders were cut out of masonite with our Glowforge Pro laser cutter/engraver. They wired the batteries and the switch manually and assembled the final project.