4 Advantages of Parametric Modeling from 3D Designer, bchan!

The designer of the month for July is Brian Chan (aka bchan). Brian designs everything from instruments to animals to superhero characters and many of his designs are inspired by nature.

I started 3D modeling as a high school student, way back when Rhino3D came out as a beta, and I still use it from time to time. Back then, my interest was mainly creating mechanical and sci-fi creations like armor suits and space ships, to make neat renderings.

Now that 3D printing has become more accessible, I mainly design a combination of aesthetic and practical models. One of the great things about 3D printing is that complexity is free, so there’s almost no limit to the intricacies one can include. I have always wanted to make organic, lifelike creations, so a few years ago I created a collection of articulated arthropods. These are available as finished prints on my Shapeways account.

My interest in sci-fi remains and has evolved to include costuming. For the past three years my ongoing project is an Iron Man suit.  It is designed from the inside out, with articulation points inspired by those insects and crustaceans I have been modeling.

Here’s a picture of me at NY Comic Con with a really cool Spiderman cosplayer I met. My helmet is 3D printed on an FDM machine, and the gauntlets were 3D printed by Shapeways. The rest of the body was made from thermo-formed plastic sheets, but I’m gradually adding in more 3D printed components for improved detail.

The newest version of the Iron Man gauntlet incorporates Formlabs Tough resin in some of the larger panels.

Recently I have been drawing many of my mechanical (and hybrid organic/mechanical, like Iron Man and musical instruments) designs in Onshape, a cloud-based parametric modeling program. While I have made many designs with basic mesh modelers (the skull in Sculptris and the articulated creatures in Wings3D) or non-parametric programs (3 generations of Iron Man gauntlet in Rhino3D), a parametric CAD program has four main advantages:

4 Advantages of a Parametric Modeling Program 

1. A parametric program makes it super easy to modify dimensions later on.
2. It’s more easy to join organic shapes, like armor panels, with precise mechanical components like hinges and mounting features for hardware.
3. Onshape is set up rather like Google drive in that it allows easy collaboration between users working in parallel on a shared document.
4. The “part studio” method of creating parts, and handy interfaces for doing splits and booleans makes it a lot faster to break one part into multiple parts or to join parts into one. Since many of these models are intended for 3D printing, I can easily divide a part so that it prints optimally.

Here are a few examples of models I’ve been working on in Onshape:

Kylo Ren’s Lightsaber, modeled in Onshape with mostly extrusions and revolutions.  

I usually start with a front/side view and draw the cross-sections for extrude/revolve based on those initial drawings. That way, I can change the proportions of the final model by editing dimensions on either the front or side view sketches.

Front View sketch of Kylo Ren’s saber, showing all the adjustable dimensions.

While solid modelers like Onshape or Solidworks are mostly used to draw shapes based on extrusions and revolutions, their loft features are pretty well-developed too.

I used a loft to define the upper “cap” of the Iron Man Mark 7 Helmet, modeled in Onshape. The loft cross-sections themselves are aligned to the front and side views drawn earlier. I have used lofts and loft-like operations in Wings3D or Rhino3D but one of the great things about Onshape is that even with complex shapes like this, the “shell” feature works reliably to change it into a hollow shape. Of course this is super handy for making armor pieces! 

There’s certainly a lot more that Onshape can do, but I highly recommend trying it out with some simple designs first. The program is free (with some limits on storage) for users who keep their files public, so you don’t have to commit anything to try it out.

Thanks for reading this far and please stay tuned as I do hope to keep adding more models to my Pinshape collection!