Jason Pohl and how xShape has changed his world of industrial design.
xShape offers a new way to make shapes as well as a way to make organic shapes. Organic shapes—those that are smooth, rounded and irregular—are the norm in nature but are avoided by CAD users because making them with CAD programs is almost impossible. It helps to be a wizard with surfaces, but few CAD users are.
It’s Not Natural
Nature is complicated, whereas all solid modeling shapes are made from combinations of simple shapes: rectangular solids, spheres, extrusions and the like. Sure, with enough simple shapes and time, you could eventually make Michelangelo’s David. In the manner of all professionals who make their art look simple, the artist is purported to have said that all he had to do was chip away all of the Carrara marble that didn’t look like David. A 3D model could be made by subtracting from a rectangular solid, with big chunks first and then smaller and smaller chips, the features getting more refined over time. Lots of time.
Streamline Moderne
CAD veterans will ask, Why even try to make organic shapes? What’s wrong with perfectly straight, round and flat ones? Is that not an improvement over nature? Why copy nature when you can improve upon it? Is it just for art?
Some organic shapes are made for purely aesthetic reasons or to satisfy the fashion of the times. This happened in the 1930s when the advent of commercial aircraft led to streamlining everything. Streamlining cars and locomotive engines may have had some justification, but the Streamline Moderne movement also shaped stationary objects such as toasters and bus stations.
But there are also very practical reasons to create organic shapes and the best are found in the interface of ourselves and the things we create. This is where our hands meet our tools, our bottoms meet seats and shoes meet our feet. At this interface, natural shapes meet man-made shapes, soft meets hard, round meets flat, and so on.
Here lives the industrial designer, that blend of artist and design engineer, and the study of ergonomics, which comes from the Greek “ergon” for work and “nomos” for natural laws. Industrial designers have flailed at ergonomic designs of tools, containers, furniture, and so on with CAD tools but gave up. Who has the time to chip away at blocks? A few design tools have evolved for their purpose—those that use splines rather than lines, the foremost and favored being Rhino 3D by Robert McNeel & Associates. Rhino has found a niche with architects as well in making conceptual models. But for the most part, Rhino has not entered the mechanical design mainstream.
Enter xShape
Dassault Systèmes hopes its entry into organic modeling, xShape, will change all that.
Available as part of the company’s 3D Sculptor “role,” xShape uses subdivisional modeling, or sub-D, instead of the Parasolid geometry engine used in mainstream MCAD applications, like SOLIDWORKS and Solid Edge.
Using xShape is literally child’s play. You start with a slightly rounded cube and you pick and poke at it until you get the shape you want. Pull out a point in the middle of one face to start a nose, for example, and points on adjoining faces that will be fashioned into ears. They are just lumps at first, but you can zoom in to add detail with ever-smaller picks and pokes. xShape uses symmetry planes so that any tweaks on one ear are reflected in the other. The surface seems to be able to add enough splines to support the next level of detail. There’s no apparent limit to the level of detail and you may have to tear yourself away. Do you really need to show the pores on David’s skin?
Wolves at the Door
Jason Pohl is an industrial designer and brand ambassador for Industrial Design at Dassault Systèmes. Pohl is familiar to SOLIDWORKS users, having wowed the crowd when he was the lead designer with Orange County Choppers, one of which was ridden onto the main stage by then-CEO of SOLIDWORKS John McEleney, bringing down the house.
Since then, Pohl has started his own design practice and discovered xShape. It has been a revelation.
“I’ve relied on SOLIDWORKS to bring my designs to life for years,” says Pohl in a Dassault SysteÌ€mes video. “The first thing that caught my eye on the 3DEXPERIENCE platform was the 3D Sculptor role and xShape. I am absolutely obsessed with it.”
Pohl likens xShape to “digital clay.” He admits that this was an area that his previously preferred CAD tool was “just not the strongest.”
xShape provides C2 surface connectivity, says Pohl, which makes for smooth transitions between surfaces. The “teeth” of a curvature comb will change length abruptly with C1 continuity but will change length gradually with C2.
C0 continuity means that the surfaces are in contact but could have formed an edge. With C1 continuity, the surfaces are tangent where they meet. If you took the first derivative of one surface where it meets the next, their first derivatives would match. Switch the display to zebra stripes, and the stripes with C1 continuity will meet each other at the interface but could have abrupt changes in direction. With C2 continuity, the second derivative of both surfaces matches where they are in contact. Zebra stripes will meet smoothly with C2 continuity. The Holy Grail of continuity is C3 continuity, which matches the third derivative of the surfaces C3 continuity and provides the smoothest transition of all. Surfaces with C3 continuity are referred to as Class A surfaces. xShape goes as far as C2 continuity, but automotive design programs like Alias can go as high as C3 continuity. This is a must for automotive exteriors, which are held to the highest standards of fit and finish of any consumer product.
To show off the organic modeling capability of xShape, Pohl uses a request from his kids, who, for some unknown reason, like wolves.
Why not, says Pohl, eager to use a creative modeling ability long denied.
Pohl starts off with a “quad ball,” a squarish sphere, if you will. He selects edges, corners and points of the splines on a face, and after only minutes of pushing and pulling, has come up with a recognizable wolf shape. Pohl looks like he’s having fun doing it—in sharp contrast to the ordeal that would have occurred using SOLIDWORKS for the same exercise.
“This is something that would be a serious challenge to pull off inside SOLIDWORKS,” he says—though he hasn’t turned his back on SOLIDWORKS altogether. The xShape model of the wolf is opened up in SOLIDWORKS so that he can make a base 3D print of the result.
