Join Scott Onstott for an in-depth discussion in this video Sculpting surfaces, part of AutoCAD 2013: 3D.
Here you will draw an ellipse over a sketch and revolve half of it to form a 3D surface. Then you will move it into position and sculpt a NURBS surface to add additional surface detail to the column capital. Open the Column 5 project file, go to the Layers panel (audio playing) and toggle on (audio playing) the Image layer. Set layer five current. Go to the top view and zoom in. (audio playing) Let's focus on making this elliptical object. Go up to the Draw panel (audio playing) and open the Ellipse flyout and choose the Axis End method.
Turn off Snap. Click the lower point here. And then click some upper point, maybe about here. (audio playing) Click a point over here (audio playing) to represent the width. Then turn off the image layer (audio playing) and orbit. We probably need to move the ellipse to line it up perfectly with this central axis line. Move, (audio playing) select the ellipse, turn on Object Snap, grab it from the quadrant point and snap it on the end of the line there.
Then draw (audio playing) a temporary line from (audio playing) quadrant to quadrant (audio playing) and then trim off half of the ellipse. (audio playing) Erase the temporary line. Go to the Surface tab and revolve the elliptical arc, from end point to end point, (audio playing) and then press Enter to accept the 360 degree rotation. (audio playing) Next we need to move this surface up so that it intersects with the blue surface, so we can see the relationship there. We'll use the Rotate command to do this.
Remember the Rotate command rotates objects around the z-axis, so we need to change the UCS before we rotate this object. Type UCS, Enter, x, Enter, Enter to rotate the UCS about the x-axis 90 degrees. Now the z-axis is parallel with the column's central axis. Type RO for rotate, select (audio playing) this surface, press Enter.
Click a point here at the center (audio playing) and you're warned because removing the surface independently of its defining curve. That's okay. Click Continue. (audio playing) Turn off Ortho and you can see how the surface is being rotated. Type 90 and press Enter. So we got it closer, but I'd like to rotate it back. A distance that's half as wide as this is in arc measure.
This is a 45 degree arc surface. So if we rotate it back 22.5 degrees, it should be right in the center. (audio playing) So let's do that. RO, Enter. P for previous, Enter, Enter. Specify the base point at one if these center snaps and type negative 22.5, Enter. So, now its centered perfectly. Go ahead and select the blue object.
Go to the Home (audio playing) tab. On the selection panel (audio playing) choose the rotate (audio playing) gizmo. Make sure Snap is off and Ortho is off. Click the red ring, we are warned that we are rotating this independently of its defining curve, that's okay. I'm going to say do not show this message again and continue. I'll rotate it about like that, and press Esc. Next, I want to sculpt this surface here to give more detail.
So, I'm going to select it and go to the Surface tab. Choose Convert to NURBS. NURBS surfaces give you more control. You can actually sculpt them by moving their control vertices, known as CVs. Click Show CV, select the surface, and press Enter. We see a few CVs here in the middle. I'd like to rebuild the surface so it has more CVs. Click Rebuild, select the surface, and you get this dialog box. Every NURBS surface has two directions, U and V that are on the surface itself. And it's hard to keep straight which is which.
So let's try 12 in U and 6 in V. Click Preview. Now we have 12 in this direction and six in the other direction. That's not what I want. Press Esc. (audio playing) Change this to 6. And change this to 12. Click (audio playing) preview. Now we have 12 going across this long direction thats better.
Now we have 6 going that way. Press Enter. Now I'd like to sculpt the surface by moving individual CVs. I'll select the surface to activate it. Then I'm going to hold down the Shift key and click on multiple (audio playing) CVs here. I might need to orbit while I'm doing this because the rotate Gizmo is in the way. Actually, I'm going to go back to the Home tab, on the Selection panel, and change this to the Move Gizmo. Then I'm going to go ahead and hold down Shift and click on these four CVs To highlight them all.
I'm continuously holding down the Shift key (audio playing) so that I can select multiple CV's. Now I'm going to position the cursor over this blue axis and click, and move it up. Look at what's happening. (audio playing) I'm sculpting the surface (audio playing) This is going to add some additional detail which should be interesting on the column capital. I'll press Esc to deselect. Go back to the surface tab and click hide c v. Now we need to array this around.
So go to the Home tab. Open the Array Flyout on the Modify panel and choose Polar Array. Select the blue object and the surface object and press Enter. Turn on Object Snap and click one of the center points. Change the number of items to eight. Press Tab. We don't need this to be associative. So make sure this is unchecked. And click Close Array. That looks great. However, it seems like it might be a little bit large. Let's scale it down a bit.
I'll turn off the green layer. And then go ahead and choose scale, select everything on the screen hold down Shift and deselect that central access line. Press Enter. Click the midpoint of the axis. And let's scale it down by 0.08. Let's turn on the other layers and see how it looks. I'll turn on Layers 1, 2 and 3.
(audio playing) It looks good. Let's go ahead and conclude by mirroring this volute to other side. Type MI. Enter. (audio playing) Orbit. (audio playing) Select crossing windows here to get the bar relief red objects and the yellow objects. Enter. Click any one of these center points. (audio playing) Turn on Ortho.
(audio playing) Click again and press enter. Now we have completed the detail in the column capital. In this lesson, you learned how to convert a regular surface into a NURBS surface. You rebuilt the NURBS surface, and turned on its CV's so you could sculpt it by repositioning its CV's. In the end you arrayed the detailed object to complete the column capital.
- 3D views, perspectives, and tools in AutoCAD
- Controlling the visual style
- Working with tiled viewports
- Composing perspective views
- Drawing in 3D
- Modeling an Ionic column
- Documenting 3D models
- Creating dynamic slideshows, animations, and renderings