Importing a CAD solid model as a Body Object

- [Instructor] 3ds Max is great for visualizing computer-aided designs because it provides many options for converting solid models to polygons. The 3ds Max body object type preserves the solid model so we can interactively adjust the polygon tessellation and change the level of detail at any time. This is something that can't be done in Maya, for example. I've got a solid works document that was kindly donated by fellow author Gabriel Corbitt of Tiger Industrial Incorporated. And he's converted that into step format so the 3ds Max can load it. And it's in my project folder in the exercise files. So let's import it. Go to the File menu and choose Import, Import. We're taken to the current projects Import folder. Select the step document and click Open. And in the Import Settings we want to get this right. We don't want to Convert to Mesh at this stage. We want to have Convert to Mesh turned off, and that way it will come in as a body object, and we can change the surface approximation or tesselation at any time. Also just for convenience, I want to change the Hierarchy Mode to flattened so that any groups or layers are discarded, and the objects are simply placed at the root level of the scene hierarchy. Click the Import button and we get a progress dialogue saying Converting using ATF, which is Autodesk Translation Framework. And that'll take a moment to import. Once that's been imported we can orbit around in the perspective view with alt and middle mouse button. And just select the outer body of this watch model and then go over to the modify panel, and I just want to change its wire frame or object color so that we can see the wires a little bit easier. Click on the color swatch and set it to a medium green color and click OK. And also so that we can see those wires and that green color and also adjust the modify stack parameters over here at the same time, we can turn on pin stack and then deselect the object, and then finally enable edged faces with F4. And if we get in closer with control alt and middle mouse we will see that the edges here are not actually polygons. They are curves. Over in the Viewport Display Settings rollout and display options we have Curves, Mesh, or Both. And the default is Both. And that means we're going to see a shaded representation of the model and we'll also see the curves superimposed over that if we have edged faces enabled. Down here in Curve Display if we want to we can increase the parametrization, or the number of iso lines. We can set Lines U to 2 and Lines V to a value of 3. And now we see more of those lines. And that's an indicator once again that this is a semi-parametric object. We can't get at the original parameters for this, but we are able to change its level of detail. And here we're just changing the display of the number of iso lines. I'd actually recommend that you display a mesh. So let's go over here to Display Options and change this over to Mesh. And now we're seeing a polygon representation. And this is closer to what we'll see when we render. But this is only for the viewport, hence the name Viewport Display Settings. The actual rendering settings will be controlled in the Rendering Approximation rollout. And each one of these has some presets. Let's go down into the Viewport Display Settings and change the Mesh Quality Preset to Coarse. And now we're seeing a very rough approximation, which is good for performance reasons, especially if we have a very heavy CAD document. We want to set that Mesh Quality Preset appropriately. Now I want to talk about active shade for a moment because there are some gotchas around that. We can now view active shade directly in a viewport. I can go up to the perspective viewport menu, click on the Standard button, or the shading menu, and switch that over to ActiveShade using Arnold, which I've set up previously. And that'll take a moment to kick in. And now we see the Arnold rendering underneath the wireframes. I can navigate with the middle mouse button. So this is a little bit deceptive, because what we get in ActiveShade is the tendering approximation tesselation. And then the wire frames superimposed over that. So we're actually seeing both of these settings at the same time. And when we look closely when we turn the edged faces back off again with F4, we'll see that this is a nice curve. Okay, so just keep that in mind, ActiveShade is actually going to show you the Rendering Approximation settings, and if you have wireframes turned on those'll be superimposed using the Viewport Display Settings. I'll go back to turn the ActiveShade back off again. And now let's talk about the Rendering Approximation settings for production rendering. And to see that most effectively we want to use a wire frame material. So let's open up the Material Editor. And in here we want to create an Arnold map to material node. To right click in the view and choose Materials, Arnold, Utility, Map to Material, and then drag out from its Texture Map slot, release the mouse, and choose Arnold, Utility, Wireframe. So now we have a Wireframe map fitting into a Map to Material material. And then just assign that to the object. Just click on its output and drag over onto the object, which is named CIRPattern1. And now that's assigned we can close the Material Editor. And let's do a production rendering. I've got that set up with Arnold as well. Click on Render Production. And that completes pretty quickly. We can see now that we've got a pretty decent production rendering here. And just to mention that we have some presets here. We can switch this over to Good and do another rendering and see what that looks like. And that's a rougher approximation. So that we can see the difference when we change some settings, let's clone this rendered frame window. And I can just sort of store that off to the side or minimize it, and the default Rendering Approximation, Render Mesh Generation Setting, is View Dependent. That means the size of the polygons is going to depend upon the size of the object in the frame. And we can illustrate that if we dolly back in our perspective view with control alt and middle mouse. Just dolly back until that watch is picking up maybe a quarter of the vertical height of the frame and then do another production rendering with view dependent approximation enabled. And once that finishes we can see that we're getting fewer polygons. We can zoom in on this window by giving focus to the window and just using the mouse wheel to zoom in so we can see that better. And here's my other rendering. We can restore that. And we can see that when we're zoomed in more closely we have a higher fidelity or higher level of detail. We can go back over here and zoom in on this a little bit more. And we can see that we have fewer polygons when we're dollied back, when the object is smaller in the frame. All right, very good. We can close that. And then also close the clone. And if you want consistent results regardless of the size of the object in the frame. You can use size dependent approximation and then I'll switch back over to the Production Quality Preset. Dolly forward, get in real close in there. And do another production rendering. Okay, and with these settings, no matter how large the object is in the frame, we'll get this same tesselation, which is good in case of animation we don't want the tesselation to change adaptively during a camera move for example. And that's how to import a CAD model as a body object and change its display settings and Rendering Approximation settings.