Description
Key Learnings
- Discover how to create 3D models by combining basic shapes to create more complex objects
- Learn how to use meshes and surfaces to create organic shapes
- Learn how to modify 3D models using sub-object selection and underlying curves
- Learn how to convert between solids, meshes, and surfaces
Speaker
- DCDavid CohnDavid is the Senior Content Manager for CADLearning® products at 4D Technologies, where he develops content standards and creates affordable training solutions for Autodesk software, including AutoCAD, AutoCAD LT and ReCap. He has more than 30 years of hands-on experience with AutoCAD and 15 years with Revit as a user, developer, author and consultant, and is an Autodesk Certified Professional for both AutoCAD and Revit. A contributing editor to Digital Engineering magazine, he is also the former senior editor of CADalyst magazine, and is the author of more than a dozen books about AutoCAD. A licensed architect, David was also one of the earliest AutoCAD third-party software developers, creating numerous AutoCAD add-on programs. As an industry consultant, David has worked with many companies, including Autodesk. He has taught college-level AutoCAD courses and has consistently been a top-rated speaker at Autodesk University.
DAVID COHN: OK. So I hope you guys enjoyed that. So just briefly, my name is David Cohn. As I said, I've been-- this is my 26th AU. I know there's only 25 of them, but there was one year where there were four around the country. And glutton for punishment that I am, I went to two of those. So I've been to 26 of these.
I work now for a company called 4D Technologies. We do video based training for about 60 different Autodesk products. So not by any way of advertisement, but I just wanted the people that didn't hear when I mentioned at the beginning, when I first came in the room, I'm running AutoCAD live in the background today. And at the end of the class, if we've got time for Q&A, we can do stuff live. But because I've got so much material to cover I'm using the tools that I use 50 hours a week for my job, which is I've recorded everything using Camtasia Studio. So all the demos I'm going to show you today are pre-recorded and embedded in my PowerPoint. And that just enables me to stay on task and hopefully also improves your ability to see what I'm doing. Because then I can zoom in and highlight things as I'm explaining them.
Hopefully, most of you had a poker chip on your seat when you came in. So that poker chip, if you then go to CAD learning website, you can sign up for 30 day free trial. We are not-- my understanding is they're not collecting any personal information. So if you'd like to see what the video based training that we do looks like go there and then while you're there you can register to win a 3D printer. OK. So we're giving stuff away at AU this year. If you didn't get a poker chip I've got a few left up here. And there's a few on the empty seats because I put them in the front half of the room. Hopefully, everybody also got a raffle ticket. Anybody didn't? Great. So we'll do that about halfway through the class.
Also I want to make sure that you do realize that if you're using the Autodesk University app, both my handout and the PowerPoint that I'm running today, minus the videos, can be downloaded from the Autodesk University app. And then you can also use that app to turn in your survey at the end of the class. And if you will send me an email, and I'll send you a reminder next week, if you'd like any of the datasets that I'm using to create the model. And I save it in various steps along the way. So if you don't think you followed it up to a certain point, you can open it up at a later stage and continue working. I'll make all my data sets available as well.
So just by way of setting the stage for this, we all work in a 3D world. Everything that we build, everything that we manufacture, everything we create is three dimensional. But for years what we've done is we've envisioned things in 3D in our mind. We've used AutoCAD to draw it in 2D. Produced 2D drawings and then someone interprets those drawings to manufacture 3D parts. And that's simply silly.
When I work in AutoCAD today, I won't say 100% of the time I'm working in 3D, but if I'm making something in 3D, I'm modeling it in 3D. And then I may use AutoCAD to create the two dimensional drawings I need. But I actually find it more efficient to model in 3D and use AutoCAD's tools to create 2-D drawings from those 3D models. That way if my model changes I can quickly update those drawings automatically using the model documentation tools in AutoCAD.
So I model 100% in AutoCAD rather than having to remember how to flatten things. So this is the model we're going to create today. And if you've seen me do this class before I've been using the same model for years, because it's such a good example of what it is we're going to create. There's multiple parts.
Many of the parts can be modeled using solid modeling. But then I have to resort to either surface modeling or mesh modeling to get the little rubber grip on the top of that air hockey paddle. So it's a nice model to work with. So that's what we're going to create today in the next, hopefully, about 45 minutes.
The tools for working in 3D in AutoCAD are located on the 3D modeling workspace. So AutoCAD comes with multiple workspaces. You've got drafting and annotation, which is what you see initially out of the box. And those are the tools for working in 2-D. But if you simply go down to the status bar and expand the workspace switching tool, or turn the workspace switching tool on, up on the Quick Access toolbar, you can switch to either the 3D basic's workspace, which is a subset of the 3D modeling tools, or the full 3D modeling workspace. And then all of the 3D modeling tools in AutoCAD become available because the ribbon changes now to show all of those 3D modeling tools.
So when you first start AutoCAD, if you know you're going to work in 3D it makes sense to start with a 3D drawing template rather than a 2D drawing template. You can start in a 2D drawing template. It's just fine. Once you're in the 2D workspace, you simply hold down the Shift key, press the middle mouse button, you orbit around, and you're working in 3-D. But if you start with the 3-D modeling workspace , or the 3-D modeling template rather, it simply provides you with a bunch of tools already preset to make it easier to work in 3D when you're working in AutoCAD. OK? And what I've done there is I enabled my 3D modeling workspace.
Once you're in the 3-D modeling workspace, if you think about the things that we create, most things start out, until you start whittling away and sculpting them, as solid primitives. So things like cubes, and cylinders, and spheres, pyramids, all the tools for creating those are located on the Home ribbon in the 3-D modeling workspace, in the solids panel. And it's a split button. So when you expand that split button you've got all those tools. Initially you see the cube tool, but as soon as you use the cylinder tool, split buttons in AutoCAD, whatever tool you use last floats to the top of that tool.
So if the last tool you used is a cylinder, then the next time you go to that tool in AutoCAD the cylinder will have floated to the top of that split button. But all the tools show up in that one split button. The nice thing about working with solids is solids are known shapes.
And when you select a solid in AutoCAD, if you go to the Properties palette, all of the properties of that solid are exposed in the palette. So if you've created a cube you'll have tools in there so that you can change the height, width, and length of the cube. If you select the sphere, then in the Properties palette you'll have a control in there to change the diameter and/or radius of the sphere. If it's a cylinder you'll have the radius and height of the cylinder.
So even after you've created that solid you can go to the Properties palette and modify the property, or you can select that object and then modify it using grips. So for example, if I go to my toolbar and I create a cylinder, which is the first shape I'm going to create to make this air hockey paddle, this tool looks an awful lot like the AutoCAD circle command when I started. It asks me for the center and the radius.
But then after I specify the radius it also asks for the height. And as I move my cursor I'm creating a three dimensional solid in AutoCAD. So the whole idea here is that the tools for modeling three dimensional solids in AutoCAD look an awful lot like the same tools we've used for years working in 2D. The only difference is now you're giving them a 3-D volume. Instead of just defining the centerpoint and radius, your defining centerpoint, radius and height. Make sense?
OK. Once you've created solids, when you click to select the solid inside the AutoCAD model, you will see grips on the solids. And then as I said, if the Properties palette is open you'll also see the properties of that solid. When you select the object in AutoCAD, if you don't see grips on all of the surfaces of the solid check up in the ribbon and see if Culling is turned on or off.
So there's a feature in AutoCAD called 3D culling. And if 3D culling is turned on, then AutoCAD will only display grips on the surfaces that are visible. So if you're looking at a cube, you won't see a grip on the bottom of the cube. You won't see a grip on the far face of the cube. You'll only see grips on the surfaces, or faces, of the cube that are visible at that point. If you want to be able to select the grips that aren't visible as soon as you turn off 3-D culling then all of the other grips become available.
But AutoCAD assumes out of the box that you don't want to see things that are not visible from your current viewpoint. And so three dimensional culling is turned on. So again, if I select this cube, or the cylinder, right? So there's the culling. If I turn culling on when I select that cylinder you only see grips on the top and at the quadrant points.
If I turn 3D culling off, when I select that same cylinder now I'm seeing a ghosted image of the radius of the base. And I can select a lot more and see a lot more grips. And so typically when I'm doing some conceptual design using AutoCAD I turn 3-D culling off.
The most recent thing I can think of that I did in AutoCAD totally working entirely in 3D was a set for a play at a local theater company, where I had turntables that were turning around. That it was a wild play. It was a play called Tuna Christmas. Takes place in the fictitious town of Tuna, Texas. And at one point of the inhabitants of the town is abducted by aliens.
And so I had a spaceship that landed on the set and the ramp came out. And the guy walks-- a bright light shines on him, he goes in the light, the ramp closes, the spaceship takes off, and carries him away. I modeled it in 3D, entirely in 3D in AutoCAD. And then our construction crew built it. It was pretty cool. OK.
Once you've built-- once you've got solids in here, as I said, you could turn on the Properties palette. And then you can adjust the solids. So the sphere, or the cylinder, or the cube, you create doesn't have to be the shape-- when you're first doing conceptual design, you may not know what the right size is. You're just kind of getting the proportions right. And then you can fine tune it.
So as long as you're working with solids and you haven't done anything to them, you can turn on the Properties pallet, or Quick Properties. If you double click on it, the Quick Properties palette comes up. The nice thing about Quick Properties is you don't have to go through every single property for a given object.
You can actually customize the Quick Properties palette so that it only shows you the properties of objects that you need to deal with. If all you're looking for is the radius and the height of the cylinder, then you can change the Quick Properties pallette so that's all it shows you.
Whereas, if when you look at the Properties palette, AutoCAD will show you literally every single property of that object that you could possibly change, including its x, y, and z location. So again, if I select that cylinder, and then double click on it-- well it's single click first then go to the Properties palette, here is every single property for that cylinder. But I can quickly change the dimensions of that cylinder by changing its properties. If I double click on it then I get my Quick Properties palette. And I'm doing essentially the same thing, but you can see I've gotten a much smaller subset of properties.
So I find that just double clicking on it is a lot easier. And again, you can customize what shows up in the Quick Properties palette. So it only-- you can customize it so it only shows you the properties that you need to deal with. OK. So for our air hockey paddle, we've created one cylinder that's the broader portion of the striker.
And now, I'm going to create a second cylinder that's going to start to be the part that you're going to hold onto. And I'm going to use standard AutoCAD commands. I'm going to create a second cylinder but I'm going to use object snap to snap it to the center of the lower cylinder.
Now, you could use 3D object snap. 3D object snap will let you snap to the center of a face. But at this stage, I find it easier to just use the standard 2D command. And it'll let me snap to either the bottom of the cylinder-- I'm sorry the circle at the bottom of the cylinder or the center of the circle at the top of the cylinder.
So I'm just going to make sure that when I object snap it, I'm going to object snap it to the center of the surface at the bottom of the cylinder. So again, I'll draw another cylinder and just turn on center object snap as an override. And so there it is. And then I'll give it a radius and I'll give it a height. And I've created my second part. And they must be showing a movie next door.
OK. The next part of this is going to be the rounded, dome-like top. And it's much easier for me to just do that as a sphere. And then I also am going to subtract some material away from my cylinder. And so what I'll do is I'll create a pyramid-- I'm sorry, a cone, which I'll ultimately use to subtract material away from that cylinder that's at the bottom. When I create the cone, I'm going to create it upside down, so the wider part at the top and then tapered to a point at the bottom. And again, I can edit this using the Properties palette. I can edit it using grips. I can edit it using Quick Properties.
So I'll start out by adding a sphere to the top. I don't even need to know how big that cylinder is. I'm going to snap the center of the sphere to the center of the top of the cylinder. All right? So I'll do an object snap to center to get it to the top of the cylinder. And then in terms of getting the diameter of that sphere I'll simply object snap to the quadrant of the cylinder.
Now, AutoCAD also has various visual styles. And when the model starts getting more complicated I'll go to a wireframe. Because now I'm going to create this cone and I want the cone snapped to the top of the cylinder, and then the point is down there at the bottom. And if I left it in a solid mode, I wouldn't be able to see through the object. So I switch to a 3D wireframe so that I can see it.
But what I'm doing now is grip editing that cone to reduce it down. Because when I subtract it away from the cylinder at the bottom, I want to leave a small lip around the side. So I simply grip edited in four units from the outside. And then I also grip edited the bottom so it's slightly smaller than that cylinder that's sitting in the center. And also that the point is now no longer at the very bottom but it's up several units from the base of that stack of cylinders. Make sense?
OK. Everything I've done so far I've simply been building this model up by creating a bunch of individual solid primitives. At some point I need to start merging all that together to create my actual solid, my single solid object. And to do that I'm going to use the exact same Boolean tools that you might have used before in AutoCAD in 2D. Basically union, which takes a bunch of objects and merges them to create one object. Subtract, which AutoCAD prompts you to select one set of objects and then a second set that you're going to subtract from the first set. Or intersect would give you just the volume that is shared by all those objects.
So I'm not going to do the intersect in this case. But I am going to do a union and a subtract. When you perform Boolean operations the order in which you perform them is important. If you perform them in the wrong order, you're going to end up with things that don't work. So in this case, I would not union the two cylinders and the sphere and then subtract the cone, because if I did I'd end up with a disjointed solid. Where the cone got subtracted the two pieces would now be separated. OK? So I first need to subtract the cone from the lower cylinder. Then I can union them all together.
So again, the tools right there on the 3D modeling panel. So I'll first subtract the cone from the lower cylinder. And I'm going to switch to some kind of a wire frame view so that I can really make sure I see what it is I'm selecting. So AutoCAD-- This is one of the few AutoCAD commands that prompts you for two separate selection sets. What are you subtracting from? And then what are you taking away from that first set? OK?
Now that I've got that volume subtracted now I can do a union and merge all these together into one solid object. So it's no longer going to be a separate sphere, two separate cylinders, and a cone. It's going to be one solid object. And now AutoCAD tells me that's a 3D solid. That at that point, is a composite solid. So the order of the Boolean operations is important. Because if I were to union all this together first and then subtract -- Right? Subtract that cone from those objects. Look what I get when I-- Right? It's not right. And yet AutoCAD will still treat that as one solid object. Even though it's obviously got a gap. It's still considered a single solid. What AutoCAD refers to as a disjointed solid.
Now, there's one other tip. By default, AutoCAD-- So are any Inventer users-- anybody ever play with inventor? OK. So Inventor has this whole idea of a history tree. Right? And you can track the history. And Inventor's really made for doing this kind of modeling. But if you're doing it all in AutoCAD, AutoCAD has a history. It simply doesn't expose the tree. But it uses the same solid modeling engine as Inventor. But by default the history is turned off.
So one of the other nice things of working with solids in AutoCAD, and the reason I like to start with solids, and I'll work with solids as long as I can, is because if I turn solid history on before I create those solids, and before I do those Boolean operations, I can still come back later and press the Control key on my keyboard. And I can still edit that sphere as if it was a separate object. I can still edit that cylinder as if-- I can still expose the properties of those solid primitives and modify them, even though, as far as AutoCAD is concerned, they've been unioned together to create one solid.
Whereas, if solid history is set to zero, is set to off, which it is by default, you can't do that. So you need to make sure that either you turn solid hist-- just type solid hist and set it to one before you ever create those primitives. Or if you forgot, select the primitive, go into the Properties palette.
In the Properties palette, solid history is one of those properties of that solid. And you can turn solid history on for that object, even if you had solid history off when you first started. And then AutoCAD will still let you do this. OK? So even though I created that and it's now one object, if I press the Control key I can still select the sphere.
I can still select-- I can select it and move it away. Right? Even though this is still one solid object because I had solid history turned on I can still go in and select these things and manipulate them and change their size. Right? And here's a great example.
So if I start a model with solid history turned on. And I create a cube and a sphere and subtract the sphere from that cube. I can still select that, or I guess in this case, solid history was off. OK? So when I selected, all I can select is the surface. But if I turn solid history on in the same drawing. And now create that exact same cube and the exact same sphere. And subtract that sphere from the cube.
I can press the Control key and select the sphere, even though it doesn't exist anymore. And change the size of the sphere and the byte taken out of that cube will update. OK? So just make sure you turn solid history on before you start manipulating the solid.
And then, again, you'll see me constantly going either into the ribbon and turning, changing my visual style, or up in the upper right hand corner, you have the in canvas controls. And you can change the visual style from inside the drawing viewport. I don't use it as much in classes because it's kind of hard to see.
And so to make it clear what I'm doing, I go up to the ribbon. But you can change it from any of those locations. And when you're working in 3-D in AutoCAD, you will find yourself doing this all the time. Because there's times when you need to see this thing as a solid object to make sure that it's looking right. And then there's times you need to see it in a wireframe mode so that you can dig into that object and start manipulating it, and make sure you're snapping to the right points.
So don't be afraid to change Visual Styles as you work. OK. When you combine these objects in AutoCAD, AutoCAD creates a composite solid. As long as you've got solid history turned on you can still press the Control key and select those individual objects. And then you can still modify them. Otherwise, you can only modify those objects using direct manipulation, which means you can only modify their surfaces, which makes it really difficult to modify the objects. I can't stress that enough.
OK. But there are some commands in AutoCAD that once you use them the solid history disappears. And you'll no longer be able to press the Control key to go in and modify those solids. So you want to put off those commands as long as possible. Because once you perform them you can no longer press the Control key to go in and modify them.
AUDIENCE: What commands are those?
DAVID COHN: I'll get to them in a couple of minutes. I'm getting a little bit ahead of myself. I'm going to jump ahead a little bit here. OK. Because there's a few more things I want to do this model before I take that step. Right now, it's kind of got hard edges. OK? So I want to add some chamfers and fillets because if we're going to injection mold this, it's not going to come out of the mold if it's got all those hard edges. It won't come out of the mold unless I add some taper to it as well. But I'm not going to worry about that.
You can use the exact same fillet and chamfer commands as you've always worked with in 2-D, in AutoCAD. But when you're working in 3-D, AutoCAD does have some additional commands. Also, when you add those chamfers and fillets, AutoCAD treats them as other objects that are added to your composite solid. And as long as solid history is turned on, you can press the Control key and modify those chamfers and fillets.
So again, if you want to use the same commands they work a little differently than they do when you're working with 2-D objects because AutoCAD immediately sees that that's a 3D object. And so the prompt changes. It needs to know what-- We're adding a chamfer right now. So it needs to know, OK, which face represents the first chamfer distance and which face represents the second chamfer distance.
But I just added a chamfer to the bottom edge using the exact same chamfer command I would have used in AutoCAD. And then I undid it. Or I can use the 3D chamfer command and it's a little bit more intuitive when you're working in 3D. Because you immediately get these grips.
And then you can drag the grips to change the chamfer distances. But either way, you can still go to the Properties palette, press the Control key, select the chamfer, go to the Properties palette, and you can still manipulate those chamfers that way, as well.
And then same thing with a fillet. I can use the same fillet command that I used in AutoCAD working in 2D. When I select a 3D object, AutoCAD knows that it's a 3D object. So the prompts are slightly different. But I don't get these grips to be able to manipulate the object.
Whereas, if I use the 3D fillet command, when I select the object notice I now have these grips and I can go in, and when I select them that fillet I can actually manipulate the fillet using grips. But I can still control select it. I can go to the Properties palette and change the fillet radius inside the Properties palette.
Or I can select it and use the grips. So there's one of those grips. Then I can drag that grip and change the fillet radius visually. But again, only because I turned solid history on so I can do a Control select to select that object.
And I don't really want the chamfer on the bottom. So I did a control select and then hit the Delete key and got rid of it. Because the chamfer on the bottom really didn't make sense. OK. So somebody asked, what commands throw away the history. Here's one of them. This is going to be an injection molded part. So it really needs to be not a solid, but a thin shell solid.
So there is a shell command in AutoCAD. It asks you to select a solid object. And then it asks you if you want to remove any faces. If you were to not remove faces what you'd end up with is a hollow solid. But you wouldn't know it's hollow. So I need to remove the bottom so that what I end up with is that shape over there on the right. OK?
And this is one of those commands that once you use it this is no longer made up of solid primitives. It's now one composite solid object that can no longer be edited. So the thing to remember here is eventually you'll probably need to use a tool like this, especially if you're doing an injection molded plastic part. Put this off as long as possible, while you're still playing around with the size and shape of the thing. Keep working with solids and don't worry about the fact that it's still just this one big solid object.
Once you know that it's got the shape and size that you want and you need to convert it into a thin shell, then go ahead and use this command, understanding that you're not going to be able to go back and change its size or shape anymore, unless you undo back to before you shelled it. But the command itself is fairly straightforward. Right? It's actually part of the solid edit command.
So it's one of the options of the solid edit command. AutoCAD prompts you to select a solid. Right? And then you press Enter. And then it says, what faces do you want to remove. And I select the face on the bottom. And I press Enter.
And then it says, how thick is it going to be. And I gave it a thickness here of 1.5 units. And there's my thin shell solid. OK? And it's thin shelled right around those fillets. So it-- obviously, if I was really going to injection mold this I'd need to add some taper.
So now I'm going to add a second part. Because this model I'm creating actually has a thin disk that snaps into the bottom. And that disk also has some stiffening ribs. So I'm going to create another cylinder. That cylinder is only going to be 1.5 units high and it's going to fit exactly inside that diameter. So I don't even need to know what that diameter is. I can use object snap to snap to the inside of that hollow shell.
So in terms of the location, I'm snapping to the center of the bottom of the cylinder. And then in terms of where, we'll just orbit around and snap to the inside quadrant. And you can see that-- is it showing up? You can see that extra cylinder that I just snapped inside there.
OK. Now I'm going to work on that plate. I think I've done everything so far in the zero layer. I wasn't even worrying about layers. I need to get rid of the top part of the striker. Because now I'm working on that cylinder on the bottom. So I can use the hide and isolate tools in AutoCAD to just turn off that upper part for the time being. Hide it. So that all I'm looking at is the cylinder on the bottom.
So it's very simple. Just select that part. Right click. And go to the hide tool. And just say I want to-- you can either isolate, which means only that one object remains visible. Or you can select it and say Hide. And then once you've got objects hidden, remember that down in the status bar that hide isolate tool will show up with a little blue circle, to indicate that-- just a reminder that you've got some objects that are hidden now. Because they'll stay hidden when you save your drawing.
So now the next thing I'm going to do is I'm going to add some stiffening ribs on that thin cylinder that I made for the bottom. Just so that it doesn't deflect once we're using this air hockey paddle. And I'm going to create this by just creating a box of any shape I want, just out in space. And then I'll move it and snap it to the center of that cylinder and start adjusting it so it's the right size.
So there's my cylinder. Now I'll just create a box. I really don't care how big this is. I just give it a length, a width, and a height. And now I'll move it to the center of that cylinder. And now all grip edit it so it snaps out to the quandrant of that cylinder. And then I'll use my properties to give it a thickness of 1.5 units.
Pretty straightforward? OK. Anybody see the flaw?
AUDIENCE: [INAUDIBLE] pieces up here.
DAVID COHN: Yeah. There's little pieces that stick out. Right? Because I snapped it to the diameter. So it's got little tiny pieces that are extending out. So I need to get rid of those. Otherwise, that thing's never going to fit into the bottom of that hockey paddle. So the way I'm going to fix that is to use another command in AutoCAD that works with two selection sets, the interfere command.
The interfere command will show you where those little pieces are that overlap. But if you use it and turn on one option it will actually create a new solid that consists of the portion that is interfering. And then you can use the subract command to get rid of the interference.
Most people that have used this command don't realize that the little red objects that you end up with can stay in the AutoCAD drawing after you've seen them. OK? So we'll simply use the interfere command. I'm going to unhide that other part because that's the part I need to see if it interferes. And now I'll use the interfere command. And I'm also going to turn on selection cycling.
So this was a tool when Autodesk-- most tools that get added to AutoCAD, when they're first added they're turned on. And then if they get in the way in later releases they turn them off. So in all the most recent releases of AutoCAD selection cycling is turned off. But in this case, I want it turned on. So I make sure that I can really see which object I'm selecting.
So AutoCAD prompts me for two selection sets. And then calculates the interference between the two. And by default I don't want AutoCAD to delete that overlapping solid. So now I've actually added a solid to my model that consists of the interference. Now I'll hide the upper portion again.
And then I'll use the Subtract command. I'll select the rib. And then what am I subtracting from the rib? I'm selecting just that tiny little end. And it's a disjointed solid. It was at both ends. So that quickly removed that overlap. And now my rib is following the contour of the sphere. So now I no longer have that interference.
OK? Everybody stand up. Because you've been in here for a little over 30 minutes and the mind can only absorb what the seat can endure. So everybody get a stretch. Want to reach in there and pull a ticket? If you had seen the number on it. OK. I'll let this finish playing.
So if I call your number-- if I don't call your number sit down. So it starts with six, three, two, zero-- everybody's still up? Two, four-- if you've got that number you should still be standing.
AUDIENCE: No. I think they left.
DAVID COHN: Oh. Well, then we'll-- And this one was a keep-- well, maybe they kept the other half. Six, three, two, zero, zero, seven. Let me see your ticket. OK, I've got a couple more things to give away at the end. So you get another chance. Enjoy some Starbucks on me.
OK. So now back to our class. There's more giveaways. So don't leave. OK. So now I've created one rib. I'm going to array that rib. Because I actually want to end up with six ribs around the bottom. So again, it's just the standard AutoCAD array command. I'm going to use a polar array. I'm going to create it as an associative array.
So I can adjust it and make sure I get it right. But then I need to explode the array. Because you can't union an associative array. You've got to eventually reduce it back into the individual parts. But in terms of creating the array, I'm just going to use the standard array command, polar array.
Make sure that I select the right part. I'm going to array it around the center of that sphere again, just a simple center object snap. And now, I can go in and I can adjust the array to make sure I get the right number of objects. OK?
But then that's an associative array so once I've created the array, if I try to union it-- because this is all one injection molded part. If I try to union that AutoCAD's going to say I can't do it. Because AutoCAD will not allow me to union an associative array. So I need to explode the array. But that's fine because now it is the way I want it. And now I can union all of that together. And now that is one solid object. OK? So now I've got my two parts. Now let's add a surface to create this nice sculpted rubber handle on the top of the air hockey paddle.
So here is where I will use-- now, when I first started doing this class I did it using a mesh. Because surfacing wasn't added until like-- what was it? 2010? 2011? So before that we only had mesh tools. Surfaces are a whole lot nicer because surfaces remain associated to the curves from which they were created, which means that even after you create the surface you can select the curve and do grip editing to adjust the curve. And the surface will automatically update as you modify the underlying curves. So surfaces are a much nicer way of working when you need to create sculpted shapes.
So in this case, I've now added layers to my model. So I can have my plastic part on one layer, my rubber handle on another layer. And I've already pre-drawn my curves. So the first thing I'm going to do is a revolve. So I'm going to revolve that curve around that center point 360 degrees to create a surface. OK? So I just created a 3-D surface by simply revolving one two dimensional curve around a vertical axis.
And then again, once I've created that shape I can still select the curve and use grips and use properties to modify the curve to get the exact shape that I want. I can also-- I'm going to cap the top of that rubber handle by using another tool that simply creates a surface patch by selecting the open edge. And I'll do the same thing on the bottom.
But the cool thing here is that when I go in and edit that, as long as I can still see my curve, I'll select the curve. And again, this a nice time to have selection cycling on. So I make sure I select the curve and not the surface. But once I've got that curve I get my gizmo. And notice I'm only clicking on the two dimensional face. So I'm only moving the gizmo in it's own two dimensional plane.
But I can select that and I can move the curve. And the surface updates in real time as I'm modifying that curve. So I can continue to sculpt this thing to get the exact shape that I want. Then to make this I eventually need to convert it into a solid. A surface is not a real shape. You can't manufacture a surface. Even if you're working with sheet metal, that sheet metal still has some thickness. OK?
So in order to injection mold this piece of rubber that's going to fit over the top of the handle, I eventually need to turn it into a solid. And I can't turn it into a solid until it's what's called watertight. It has to have a top and a bottom, as well as that outer surface. So the first thing I'm going to do is patch this to fill in the gap at the top and the gap at the bottom. And I'll do that by using a surface patch tool.
And again, it's a very straightforward tool. So I'm going to make sure that I'm on the proper layer. And then I'll simply say, OK, patch this surface. And AutoCAD prompts me for the edge. I'll select that edge. And then AutoCAD has the notion of continuity. So I want this curve to be smooth. I want that patch-- if I change the curve of the lower portion of the surface that we swept around, I want the top to continue to be a nice smooth curve all the way around.
So AutoCAD has the sense of g-0, which is basically no continuity, g-1, which is point continuity, but not three dimensional continuity, or g-2. So I'm making that surface patch g-2 continuous. And then I also gave it a bulge factor. The patch that I'm putting on the bottom I don't care. So I made that g-1 continuity. And then I added a fillet around that.
Once I've got this thing as an enclosed water tight surface, I can still continue to grip edit it those curves. Right? Because right now it's still a surface. I haven't converted it into a solid yet. So I can still grip edit those curves and continue to adjust that surface. Once it's the shape I want, then I need to convert it into a solid. Because I can't do anything with surfaces.
So I'm going to use a tool to convert it into a solid. But then it's one big solid block. It needs to fit over the injection molded portion of that hockey paddle. So I'm going to need to subtract that hockey panel solid from the rubber handle that goes over it. But now, since the hockey paddle is a thin shell I'm going to end up with a disjointed solid.
I'm going to get the part of the rubber that's on the inside of that hollow cylinder. And I'm going to get the portion that's on the outside. And AutoCAD is going to treat it as if it's one solid object. So then I need to use another tool to split it into two so I can get rid of the one that really doesn't exist on the inside.
So here is my surface. Right? Right now it's a bunch of different surface patches. Now I'm simply going to use this tool to turn it in-- that entire object just window select it. And now it's a solid. OK? And now that it's a solid I can use the same subtract tool. We'll turn on the lower cylinder.
But because subtract throws away whatever you subtracted from the object, I'm going to make a copy of that first. Because I know once I do a subtract, the stuff I subtracted from the green rubber handle is gone. And I still need the rest of the paddle. So I perform my subtract. And then I'll hide that base.
So now, you can see it's got-- that's all one solid. Right? Doesn't matter where I hover over it. AutoCAD sees that as a single solid. But now I can use the separate command, which again, is just an option of the solid edit tool. And I can separate it into two separate. Solids and then delete the inner part.
And then I'll turn the base back on. Because the base is in the right spot. So I'll unhide that. And now I'll just move the copy back in. So it's snapped to the center. So we'll just snap it back to the center of the other part. I'm done. Cool?
AUDIENCE: Wicked cool.
DAVID COHN: Wicked cool. As my friend, Matt Murphy, would say, wicked cool. So I did want to show you-- so I said, back when I first started doing this class, the only way to model the handle on the top, the rubber handle, would have been to use mesh editing. Now I prefer to use surface editing because I can continue to modify the surface by editing the guide curve.
But if I wanted to do this in mesh editing it does take a bunch of steps. And meshes are very difficult to modify to get anything precise. But they do let you create some really interesting organic shapes. So real quickly here is how I would do this if I was using mesh editing. I would start out with a mesh cube. And I'd put the mesh cube kind of centered on the sphere.
And then once I've got that mesh cube I'd add a crease around the bottom, because I want the bottom to kind of have a hard edge. But I want to be able to make the top part very sculpted. Then don't increase the level of detail on that. And when I do, I start to get this more curvy shape. I don't need the bottom. So I turn the bottom off temporarily. Then I'll take the top part, where I need to add more detail, and I'll add more facets to the top part of that mesh. And then I can go in and I can actually grip edit those individual facets and start sculpting it.
But as you can see, this is more of a trial and error way of modeling. Whereas, when you're working with surfaces as long as you construct guide curves you can then go in and grip edit a very simple curve to modify what otherwise is a very complex shape. But again, because this is a mesh I can't do anything with it. I need to convert it into a solid. So eventually after I get done sculpting this, and with the mesh I'm adding some little finger recesses, which I didn't do with the surface.
So that's easier to do in mesh editing. Because mesh editing is very organic. Whereas surface editing is kind of organic. So once I get the shapes that I want I still need to convert this into a solid. Because right now it's a mesh. So there is a tool in AutoCAD that will convert a mesh into a solid, just like there was to create closed surfaces, watertight surfaces, into a solid.
So now that's a solid. And now that it's a solid I can go through the same process and subtract a copy of the other part from that mesh. And then do the same thing. Once it's a solid, I create this disjointed solid, separate it, get rid of the inside part, and then move my other part back in. And I'm essentially back at the same point. OK? I'll let this finish.
So two different ways to accomplish the same thing. OK. Real quickly, I can then apply materials to this so I can create a very realistic looking object. So materials in AutoCAD are very simple. Again, while you're working in the 3-D modeling workspace, just go to your visualize toolbar. And that's where you'll find all the rendering tools. And I selected a red rubber looking material for the grip and a white plastic material for the base.
And then once I've created my 3D model, this is why I like to model in 3D, even if what I'm trying to do ultimately is create 2-D drawings. Because I can then take that 3D model and go into the model documentation tools in AutoCAD. And quickly create two dimensional drawings of that 3D object. The nice thing being, if I went in and made any changes to that 3D object they would update, including any dimensions I placed on it. Right?
So by working in 3D and letting AutoCAD create the 2D drawings for me, if I modify my 3D model the two dimensional drawings will update automatically. So this has only touched on one subset of 3D modeling tools in AutoCAD using a very simple object. But there's lots of other tools. One of the most powerful tools you can use in AutoCAD is the press pull tool.
So anybody use FormIt or SketchUp? Right? So this is kind of a SketchUP like tool right inside of AutoCAD. If you draw a circle on the face of a solid, you can then use the press pull tool to extrude that circle out or pull the circle right through to create a hole through that solid. Right?
So just real quickly, just a very simple cube. And I've drawn some-- I've sketched some circles on the surface of that cube. And if I select them, if I select inside the circle it adds it as part of that solid. If I select the circle itself it added it as a new solid. If I select and push it through it created a hole through it.
If I select a two dimensional curve it creates a surface. If I hold down the Control key, I can make it continue to taper. If I don't, it just takes that and extrudes it. And you can even do multiples. And when you do multiples, by selecting the multiple option, now when you extrude it it does all of them the same distance at once.
So it's a very powerful tool. When you're working with surfaces AutoCAD's got tools that let you sketch right on the surface. And then you can create holes in the surface and extrude out from the surface. So if you wanted to do something like a surface based teapot, I can place some guide curves on the surface. And notice AutoCAD is-- I'm sketching right on the surface, because AutoCAD knows that surface exists.
I'm kind of drawing a spline, a closed spline on the surface, and then I can use a tool to subtract the inside of what I just created from the rest of the surface to create that hole. And then once I create the hole I can extrude the edge to create spout. And then after I've created the spout, I can use the 3D fillet tool to add a 3D fillet where those two services intersect. And then I could eventually turn this into a solid so that I could actually manufacture it.
Because again, surfaces are a synthetic object. You can't-- they're great for modeling something. But ultimately, if you want to do something that you can manufacture, even if it's being manufactured out of thin sheet metal, you still need to convert it into a solid. And there's lots of other tools in AutoCAD. You can-- I showed you the revolve tool earlier, where I revolved the curve to create the surface for the rubber grip.
But I can extrude and if I extrude a two dimensional object, it creates a surface. If I extrude a closed object, that was drawn with a polyline, it'll create a solid. I can sweep something along a helix, a three dimensional helix, to create a spring. I can loft through several two dimensional profiles to create a three dimensional object that's being lofted.
And I can even, by setting up guide curves, in just a few clicks, I can create a three dimensional tea-pot and lid by simply first revolving that curve. And then I'll revolve the inside curve. And then I can subtract the inside curve from the outside curve. I can do a sweep along that guide curved to create the handle.
Or I can do another sweep, or in this case a loft, between those two profiles along that path to create the spout. Then I created some concentric circles. I'll loft them along the same guide path to create the inside of the spout. You can see. I'm doing it real quick. But you can see where it's going.
I union the inside together and subtract it from everything else. And in a few seconds create a very intricate three dimensional teapot. Right? And this is just all-- I've sped the video up. Obviously, I wasn't quite working that fast. It's like those people you see sketching, you know-- Yeah. I'm good. But I'm not that good. Right?
But I mean, I should have used a different color. But there's what it looks like in 3-D rendered. Right? I mean, you can model anything in AutoCAD. You truly can. Right? So there's the teapot. I modeled a little hand drill in AutoCAD using the same kinds of tools.
So I mean, you really can model anything in 3D in AutoCAD. Is it the best tool? No. If you are manufacturing something you should be using Inventor or Fusion. Because they've got tools that understand what it is you're going to manufacture. Like I said, my injection molded part is not going to be able to be extracted from a mold because there's no taper. Right? I
Do a lot of set design. And after I built that set for Tuna Christmas, the next set I modeled inside RevIt. Because I realized, wait, my set is nothing more than a building built inside a building. So I now use RevIt for a lot of my set design. But you can-- if AutoCAD's the tool you've got you can model entirely inside AutoCAD.
OK. Let's do a couple more of these. I won't make you stand up this time. So I've got-- how many of these do I have? One, two, three, four-- OK. So let me pull four of these. So who has 045? Anybody? Back there? So here is a-- these are 16 gig thumb drives, which I think everybody could probably use. 049. Could you pass that back to that gentlemen, please? 070.
AUDIENCE: Oh. So close.
DAVID COHN: And one more. 006, one of the early arrivals. I trust you. OK. So we've got a couple of minutes left. If you want-- again, so if you've got the-- did everybody get a poker chip? OK. So see me afterwards and I'll give you a poker chip. So again, the company I work with is Four D Technologies.
We do the CAD learning video based training, the same tools that I used to record the lessons today. Please-- you can go out there. Your poker chip will get you 30 days free to any of our courses. We've got courses on about 60 different Autodesk products. And we'll also automatically enter you in the drawing for the little 3D maker bot.
Remember to download the course materials either from the AU website or using your app. Both the PowerPoint and the handout are there in color PDF. And then if you enjoyed this class, please remember to vote. Remember that one is poor and five is excellent. Some people, I think, reverse that sometimes.
And if you'd like the data set at various iterations, as I worked through this so that you can go home-- and I hope my handout, my intention with the handout is that so when you read through it-- I went very quickly today to get through a lot of stuff. But I explain in great detail in the handout. And you should be able to take the data set, or even working without the data set, go through the handout and recreate everything I did today.
But I put the teapot model up there as well. So if you want to try something more intricate . I've got all the guide curves already built, if you want to try the teapot. I don't remember if I've got the drill in there. But I'll see if I can find the hand drill and put that in there as well. OK?
And then again, here's some additional contact information. So our website is cadlearning.com. That really is my live email address. So I'll stick around. I don't know if there's another class coming into this room afterwards or not. But I'll stick around and answer questions. We publish a newsletter. I've got a blog. I'm available on Facebook. So please feel free to get in touch with me. And again, thanks so much for being here at AU.