Surface Modeling with SOLIDWORKS 2016
There has been a progression over the years from the pencil to 3D modeling. With that progression has come great capability. Now, you can build your product digitally, specifying the appropriate materials, and pull all kinds of important information out of it. How much will it weigh? How much material will you need to purchase and produce it? Even, what colors will you need to make the product? You can also drop your product into virtual environments and see what it will look like in use. So much can be quickly and easily defined with a 3D model. It truly is amazing. The performance you require will depend on the tools you use to build your model. SOLIDWORKS has stepped up to the proverbial plate with SOLIDWORKS 2016—and can it model!
Beneath the Surface
Building a 3D model can be done in many ways, and SOLIDWORKS 2016 is up to the task. In industrial design, a virtual model must embody the right elements of style and function. It has to fit the purpose, as well as the hand. It has to both look good and work. To get there, industrial designers use a variety of tools. One of the most powerful is surface modeling. By building with surfaces, you can create just about anything you can imagine. SOLIDWORKS 2016 has tools to not only do that, but also make it relatively easy.
Figure 1. With C1 continuity, surfaces intersect abruptly and you can make out an edge.
One of the most important terms to understand is continuity. This is how a surface interacts with, and is influenced by, other surfaces on a model. Tangency (or C1 continuity) is where the surface curvature intersects abruptly at only one point of contact. It can generally be seen because the curvature only matches at the point of intersection (see Figure 1).
Figure 2. With C2 continuity, it’s hard to see the intersection of two surfaces.
C2 continuous curvature looks smoother because it both intersects and shares angles between the intersecting surfaces. It is hard to see the line that forms at the intersection of two surfaces (see Figure 2). That’s what makes it attractive on an instinctual level. With a smooth transition, reflections glide over edges instead of just ending at the next surface.
Figure 3. A boundary surface just needs a closed loop.
Complex organic shapes are difficult if not downright impossible to achieve with solid modeling because, in nature, exact tangencies are hard to come by. But SOLIDWORKS 2016 has tools to handle almost any challenge. You can extrude a surface, revolve, sweep and loft—all of the things you would expect. (These are all available in solid modeling as well.) But you can also create boundary surfaces (by identifying curves that create a fully closed loop—a perimeter in 3D space, see Figure 3), fills (for when things just don’t come together) and freeforms. The Mid Surface creates a surface between two surfaces that is equidistant from each—like bisecting an angle.
As powerful as surfacing is, SOLIDWORKS 2016 is at its heart a parametric solid modeler. It has all the requisite solid features you need to create wonderfully complete models. But that’s not to say that it won’t do surfacing. In SOLIDWORKS 2016, solid modeling can work a lot like surfacing. There are features and capabilities that can get the same results. Take for instance SOLIDWORKS 2016’s C2 Edge Blend. This allows you to create a blend on an edge that is beautifully smooth.
If you work with imported models, you’ll appreciate SOLIDWORKS face-editing features. These features treat the faces of your model as if they are surfaces. How many times have you needed to remove features from imported models? In SOLIDWORKS, you just select the faces to remove and they’re gone. You can even move and offset them. What if a hole isn’t in the right place? No problem. Select the faces to move, and tell them where they can go. You can choose to move them in a delta from where they are or from point to point. And when someone sends you a model that isn’t the right thickness, just offset the face/surfaces. You can replace a face with the geometry of a selected surface. You can heal imported surfaces and knit, trim and extend them.
Figure 4. Zebra Stripes are a great way to show how light will play over your model.
Bi-Directional Sweep, also new in 2016, allows you to place your profile sketch anywhere along the sweep path and create a feature that spans the entire path. You used to have to create your profile at one end or the other. Instant3D allows you to click and drag your model geometry to make changes, just like a surface mesh. Even before this release, SOLIDWORKS gave you some really useful surface analysis tools. Among them are Draft Checking (which will allow you to see what faces have appropriate draft), Thickness, Curvature, Minimum Radius and Deviation Analysis. Using Zebra Stripes is one of the best ways to visualize how smooth your model is, as it allows you to see how abrupt the transition from one surface to another is (see Figure 4). You can also use a bitmap the same way. Surface Flatten will take faces and surfaces and unwrap them into a flat pattern. This is great for building things out of sheet materials.
Whether you use solids or surfaces, SOLIDWORKS 2016 has tools that will speed you through your tasks. For more information, see www.solidworks.com.
About the Author
Michael Hudspeth has been a designer for two decades, a lifelong artist, an avid model builder and author (specializing in science fiction). He, his wife, two daughters and one too many cats thrive in the great American heartland, just outside of St. Louis, Missouri.