T-Splines simplifies organic CAD modeling in Rhino and SolidWorks, making it easier, faster, and more fun. T-Splines gives a high-quality human feel to your designs, which nicely compliments the exact engineering details that can be added with other software.
Greetings and salutations cadjunkies, my name is Adam and I am an industrial designer and founder of cadjunkie.com, where you can find a veritable cornucopia of tips, tricks, and training for digital design tools. Welcome to a special presentation of tsElements for SolidWorks, brought to you by the good folks over at T-Splines.
Today we’re going to be talking about T-Splines little bro,’ tsElements for SolidWorks. I personally use tsElements in my studio on a regular basis for real-world product design situations (which I’ll talk more about in a minute). It has literally changed the way I use CAD tools for rapid product development—and even manufacturing. Not only can I build organic models much more quickly, I can accomplish things that were virtually impossible before T-Splines came along.
There are lots of ways you could make use of T-Splines in your own workflow, but I’m going to show you how I use it in my own work. The basic premise is that SubD has huge advantages in terms of speed and flexibility for freeform modeling, while NURBS and parametric solid modeling are far superior to SubD for adding precise details, and for prototyping, machining, and manufacturing. T-Splines bridges the gap, allowing me to use both SubD and CAD together, rejoice and sing choirs of angels, this is sweet, sweet news for those of us who straddle the creative and manufacturing worlds.
Today we’re going to demonstrate the power of tsElements for SolidWorks by walking through a real-world workflow. There are actually two things I want to show you: first, we’ll model a toy car in modo, use modo to create clean, simple B-side offsets, and then export the surface to SolidWorks to add the final details before prototyping. After that I want to take you even further into the rabbit hole and demonstrate a wild and crazy sculpting workflow I used for a toy design project last week, and trust me, this one’s gonna blow your mind.
The purpose of this video is to demonstrate the power and flexibility that tsElements for SolidWorks gives me, but not the nitty-gritty step-by-step. For that kind of detail you’ll want to check out the other tutorials on cadjunkie.com. Ready to go? Lets do this.
First, let’s take a quick look at SubD modeling, just so the SolidWorks users out there understand what we’re looking at. I’m going to be using modo to demonstrate, but you could substitute in any SubD modeler here; each has its own srengths, but fundamentally SubD is SubD, whether it’s modo, Lightwave, Cinema 4D, 3DStudioMax, SoftImage, Maya, Blender, or any of the billion or so others.
Here’s the basic idea: I can create a cube, hit the [tab] key, and the cube will be converted to a "Subdivision Surface," or SDS. I can hit [tab] again to go back to the parent cube. SDS is a just a way of taking a blocky "cage" mesh and converting it to an ooey-gooey smooth shape. By adding more details to the blocky cube, I can then see those details smoothed out using the [tab] key. I can make modifications to the mesh in either smooth or faceted mode, and as you can see, I can very quickly create extremely organic surfaces.
While creating extremely organic forms is incredibly fast and intuitive in SubD, you’ll find that adding very crisp, tight details is much more difficult. Take a look at this toy car model: I want to cut some perfectly-circular holes for the wheel wells, but believe it or not that’s actually really hard to do in SubD. Or how about cutting out the door panels? That’s actually ridiculously difficult in SubD.
So this is where a CAD system like SolidWorks would really pull out ahead, but until now there has been no way of getting that smooth SubD mesh into SolidWorks. But I have tsElements for SolidWorks installed! All I have to do is save my modo mesh as an OBJ file, head over to SolidWorks, and File > Open. Select OBJ as T-Spline from the file type dropdown, and find the file.
Bam. The result looks like it did in modo, but now it’s a patchwork of curvature-continuous surfaces that can be used just like any other surface in SolidWorks. I can use the Trim tool to cut the model in half across the X.
I can sketch the profile of a door and use it to trim the surface to cut out a door panel.
I can sketch the profile of a wheel well, and extrude a surface that intersects with the T-Spline surface, and then use a face fillet to create a constant-width curvature-continuous edge round between the two surfaces.
Now, even after adding all those surface details, I can edit the tsElements import feature and make minor adjustments to the original SubD cage. When I exit the feature, the trimmed result updates to reflect the changes.
Okay, lets take a few steps back and look at another workflow issue: the B-sides. That’s right, creating A-surfaces for the exterior of the product is one thing, but what about the offsets for the interior of the product?
Here I’ve created a really simple shape in modo and brought it into SolidWorks as a T-Spline surface. Since the shape is closed, tsElements has automatically converted it to a full-fledged solid in SolidWorks. We can use any other solid features within SolidWorks. For example, I’ve created a circular pattern of stripey details all the way around the engine, along with a revolved-cut to create this little visual part break. Since this is a bona fide solid, I can even run the Shell tool, select a wall thickness, and end up with a hollow solid body, all ready for rapid prototyping. I can even go back to the original T-Spline import feature, and as beflore, I can make changes to the parent surface and see those changes propogate to all of the child features! Fantastic.
But our toy car is going to be a bit more trouble. You see, CAD systems in general have a lot of trouble offsetting surfaces when the resulting offset would intersect with itself, as it would with these sharp corner details on our car. If we try to run the Shell tool with this surface, it’s going to fail on us.
Fret not, my children! This is just for rapid prototyping after all, so we don’t need a perfect offset; close is close enough! So here’s another application for T-Splines. Let’s hop back over to modo and see what we can do about this. I’ll just take that original mesh and duplicate it. Now watch what happens when I use the Push tool to offset the surface: see how the sharp corners intersect with themselves and totally jack up our surface? To fix the problem, all we have to do is remove those problematic edge loops. I’ll just work my way through the model finding problematically small polys, and remove the corresponding edge loops.
Now when I use the Push tool, I get a nice clean result. I’ll push those surfaces in by 3mm, and export them to OBJ.
Back in SolidWorks, I once again use File > Open, OBJ as T-Spline, but this time I’ll click the Options button, and tell tsElements to import the OBJ into the current document, rather than creating a new one.
Sweet! Now we’ve got two surfaces, an A surface and a B surface. I can create a planar surface across the bottom of the car and use the trim tool to create a closed manifold surface. The surface is closed, but it’s technically still a surface body. To make SolidWorks recognize it as a solid, use the Thicken command, and check the "create solid from enclosed volume" modifier. We now have a full-fledged solid, complete with offset interior surfaces, ready for details, mechanical features, fillets, chamfers, screw bosses, structural ribs, rapid prototyping, or machining.
Now, generally speaking T-Splines works best with relatively simple, lightweight mesh data, and you’ll also want to avoid self-intersecting meshes. You really want to avoid converting high-density mesh data in T-Splines in general, particularly if you want to be able to modify them from within SolidWorks. But that said, I’ve converted some pretty gnarley SubD meshes to T-Splines with impressive results. For example–and this is the last thing before I let you go–ast week I had a client ask me to design a toy that looked like it was whittled out of wood. Yes, whittled. My heart said "yes!" but my CAD brain was saying "no friggin’ way!!" And then I had an epiphany: what if I could sculpt the A-surfaces in modo, and then export them to SolidWorks using tsElements? It was worth a try!
So I’ve modeled this sling shot shape as an example surface, and notice I’ve already created a 2.7mm offset surface to serve as my B-side. Now I use modo’s new Pixar SubD’s to do some multi-resolution sculpting. I could even take advantage of P-Subs’ new edge-weighting features to sharpen edges without creating more geometry. Here you see me just using the "Flatten" tool to make the mesh look irregular and faceted, as if it had been hand-carved.
Now here’s the trick: T-Splines can’t read Pixar SubD’s on its own, but it can read the raw mesh data. I’ll duplicate the PSub mesh since the next step is destructive, and then I can run Geometry > Freeze, and end up with a dense-but-mostly-clean mesh.
I’ve saved out an OBJ of the final frozen slingshot mesh, and provided it’s not too dense, tsElements eats it right up. Unbelievable: now I can use this as the basis for a manufacturable solid model, ready to send to the factory.
And that is just the beginning! My good people, if you routinely use SolidWorks to design physical things, and you want to build highly organic surfaces rapidly, particularly during the early stages of the design process, you need tsElements. I’ve only had tsElements for a few weeks now, and I’ve already used it for toys and movie props. My clients are blown away, and my coworkers are scratching their heads wondering how I do it, now you know the secret!
That’s it, kids. Keep in touch!