For years, the CAD world has been splintered. Parametric modeling and direct modeling have been at odds. While parametric modeling has dominated the MCAD landscape, the insurgent potential of direct modeling has challenged its authority.
For its part, parametric modeling has held sway among mechanical, electrical and other designers because of its inherent ability to create structured components that can be customized in a very linear manner. But the problem with parametric modeling is that when it comes time to make sweeping surfaces like the type you’d see on a slick roadster, the amount of cajoling needed to make a desired shape can be a nightmare.
And that’s where direct modeling comes in.
With direct modeling, complex surfaces can be created by pushing and pulling a surface in the same way that you’d sculpt a ball of clay. But though you can create more complex geometries in an organic fashion with direct modeling, you lose nearly all control over how a model can be adapted to fit other configurations.
Is there a way that the two modeling paradigms could be brought together to form a more perfect union?
Parametric Modeling
All of those sketches came together to make this fountain.
But for parametric modelers, design intent doesn’t end at the sketch level. Once a sketch has been completely drawn and dimensioned, it’s used as the basis for creating a feature. Just like a sketch, features can be related to one another, making a model’s related component in a model dependent on driving factors that can be defined by a user at will.
While creating parametric models can be extremely time consuming and complex, their ability to define the geometry of machined parts or reconfigurable components make them extremely useful for a business whose products require customization.
With a parametric model, designers can simply get dimensional input from a customer and use a parametric model to create a custom configuration in short order.
Direct Modeling
In contrast to parametric modeling, direct modeling or, in the case of Fusion 360, “form modeling,” begins by selecting one of several stock forms such as a quadball, a box, a torus, a sphere, etc. With a useful starting form in place, users are asked to define the number of faces that a form should have and its overall size. While the size variable of a standard form is less important (pushing and pulling the shape is going to change that value after all), the number of faces a form has is critically import.
Though it might not be obvious in the abstract, the more faces that an object has, the smoother it becomes. In the case of direct modeling, having more faces also means its surface geometry will be more complex.
After the appropriate number of faces has been added to the form, users simply select the faces that they’d like to modify and push, pull, rotate or twist with the selected object.
Though it does take some time to get used to (this coming from someone schooled in GD&T and parametric dogma), once the learning curve has been achieved, direct modeling makes creating dynamic, organic forms simple.
So, with that being said, can these two modeling paradigms work in concert?
Jasco Products Puts Fusion 360 to the Test
For the last 40 years, Jasco Products has been developing innovative consumer products licensed for General Electric (GE). Whether you’re talking Disney-themed electronics or nightlights that provide illumination when power fails, Jasco’s designers have consumers covered.
The GE 2-LED Power Failure Emergency Light’s previous form.
Fortunately, Lange’s boss introduced him to Fusion 360 and insisted that he give the software a try. After kicking and screaming through Autodesk tutorials, Lange finally admitted to himself that Fusion 360 might actually offer a more efficient method for design products than his former tools. Lange suspected that Fusion 360 would offer him more efficient workflows and an easier modeling paradigm, but he needed proof, so he got to work.
“Honestly, the last 20 projects that I’ve modeled have been built using Fusion 360,” said Lange. “The user interface is so simple and quick access to intuitively-sourced tools with the tap of my right click makes my work far easier.”
But beyond quick and easy access to his tools, Lange also found the ease with which a user can move between the “Sculpt” and “Model” paradigms in Fusion 360 to be a huge time saver.
On one recent project, Lange was tasked with redesigning the GE 2-LED Power Failure Emergency Light that doubles as a flashlight when a home or office experiences power failure.
While the original design was built using Lange’s old tools, the new design was modeled using Fusion 360. According to Lange, when using his old software, building the surfaces and ergonomics of a nightlight such as the Power Failure model was often frustrating because he’d have to stitch or thicken surfaces and then just hope they’d knit together. But with Fusion 360, Lange was able to quickly sculpt the sweeping ergonomic design of the nightlight from a single, unified surface and then switch to the parametric “Model” paradigm with the click of a button. Fusion 360’s seamless workflow wasn’t stopping to correct surfacing issues, which allowed Lange and his team to move forward and develop products faster.
A Grand Union, Finally
Parametric designs should always be used to develop the critical components that form the backbone of a product. Whether that be the electronics or mechanical components that make a product go, parametric modeling has all the tools to make a complex system work and fit precisely.
On the other hand, a product’s ergonomic form, or overall aesthetics, should be left to direct modeling.
But is there a single tool that allows you to work with both modeling paradigms in a single, fluid environment?
There is. It’s Fusion 360, and I think its ability to work with both modeling techniques in such a fluid manner makes it a very potent tool.
Why?
In my mind, having the ability to control both types of modeling makes Fusion 360 a tool that can be shared among different types of designers in a company. By giving industrial designers the tools to push and pull surfaces so they can sculpt the design packaging, while concurrently offering a parametric environment in which electrical designers can plot board and wiring locales, Fusion 360 transforms itself into a collaborative product design platform.
Maybe all CAD packages ought to be heading this way? For now at least, Fusion 360 stands apart.