building a teapot lesson 3 building a teapot · building a teapot 11) select the birail modeling...

Building a Teapot

Lesson 3 Building a Teapot This lesson focuses on building surfaces while using construction curves. You will also use the surface intersection tool and understand the advantages of a Construction Tree based modeling environment. • NURBS curves. • Lathe. • FillPath. • EdgeExtract. • Pipe. • Birail. • Surface Intersections.

Learning solidThinking 1

Lesson 3

This lesson can be completed in about 30 minutes. You will start modeling the base of the teapot by defining the curve that will then be revolved.

Organizing your workspace 1) If you are already working with solidThinking, choose the

from the File menu, select New and save the scene you were working on. Otherwise, you must first run solidThinking.

2) Choose the default layout option from the Layouts panel

(choose View4Layouts).


Building a Teapot


3) Open the Grid Setup panel by selecting Edit4Grid Setup. 4) Choose the Grid#1 tab and set X, Y, and Z to 0.5.

5) Then, choose the Grid#2 tab and set X, Y, and Z to 1.

6) Leave all grids visible and enable Snap to Grid 1 as in the next picture.

Then, click the Close (X) button. Note: solidThinking allows you to define up to four different grids, each of them with its own origin and spacing, grid type, and color.

Lesson 3

Drawing NURBS curves

You will now draw the curves that will later be used for the construction of the teapot body.

1) Click the NURBS curve modeling tool icon or select the

Tools4Curves4Nurbs curve menu item. This tool enables you to draw a NURBS curve.

2) Draw the curve you see in the picture of the next page

following the same points.

Press the Spacebar to end points insertion.


Building a Teapot

3) To enlarge the Front view, click the Zoom icon in the title bar and drag in the view without releasing the mouse button.

4) Now, you can create a second curve that will be used to

construct the teapot lid. This is another simple curve you create using the NURBS modeling tool. The working axis is the same.

Draw the curve as in the picture below starting from the top,


Lesson 3

Press Alt + e , which is the shortcut for the New Entity command. Note that while the console is prompting you for an operation, the Modeling Tool panel is disabled. However, you can still use the command shortcuts. If you do not want to use the shortcut, you can press Spacebar . In the Modeling Tool panel, press the New Entity button.

Click in the view and place a new point as in the picture below, then press Spacebar .

To obtain the corner, you could also position two points at the same place, but this approach is less correct from a mathematical point of view. In any case, the number of replicated points should NEVER be higher than "curve order - 1". In other words, if you have a curve of order 3, you can replicate only 2 points at the same place.


Building a Teapot

Creating a revolved surface

To obtain the body of the teapot, you can use the Lathe modeling tool, which creates revolved surfaces by rotating around any user-defined axis. 1) Click the Lathe icon or choose the Tools4Surfaces4

Lathe command. 2) Click the first curve and press Enter to confirm the values

in the console: 360 degrees of rotation; revolution axis 0, 0, 0; vertical axis.


Lesson 3

3) By now, you have created the base. By repeating the

procedure for the other curve, you will attain the basic teapot as shown in the image below.


Building a Teapot

Building the teapot spout

In the Front view, the spout of the teapot can be easily created by using the Birail Modeling Tool. 1) Start with a circular section that you can get with the Circle:

center, radius modeling tool. 2) Draw a circle with center 0, 0, 0 and radius 1.

3) Using the NURBS modeling tool, design two curves like the

images below, which show the curves in relation to the teapot body. They will represent the two curves to be traced with the birail function to build the spout.

Note: The birail surface is created according to the rails; thus, you can position the circular section at your convenience, depending on your needs.


Lesson 3

4) Now, apply the Birail function by clicking it. Select first

the circle (the section of the shape to be created) and then the two curves you have just attained. The outcome will be as the one shown in the image below.

Now, to find the intersections between two surfaces, you will discover how to split the spout and retain only the part external to the body of the teapot. You will turn the body and spout of the teapot into a single object.

5) Select the Intersect CT modeling tool. 6) At the program console prompts, select the two intersecting

surfaces.


Building a Teapot


Lesson 3

7) Once you have selected both surfaces, the console prompts

Choose which surfaces will be split and offers you three options: Both, 1st, 2nd.

8) If you type B (Both), you will split both surface #1 and

surface #2. By choosing 1st or 2nd, you will only split surface #1 or the surface #2, respectively. Type B.

9) The console prompts Select faces to remove. Click on any

faces outlined in dark blue to select them for removal from the final object. Hold the CTRL key for multiple selections and press Spacebar to end. You can deselect a face by holding the CTRL key and clicking on its yellow wireframe.

10) After choosing the faces to remove, press Spacebar to end

and end the creation phase of the tool. The “removed” faces will no longer be a part of the end result object.

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Building a Teapot

Using pipe to create the handle

You now need to design the handle, which is formed by three parts: the first is the section of a round tube that is adapted to the natural curve of the object; out of this tube comes the second piece which is a slender black metallic bar; and, on the upper side, an anatomical hand-grip equates to the third part. We will start using Pipe, a modeling tool that lets you create a surface by sweeping a cross sectional profile curve along a second path called extrusion path. 1) First, draw a NURBS curve as in the pictures below. It will

be our extrusion path.

2) Then, create another circle with a radius of 1. It will be used as the cross sectional profile. Working in the Top view, you can easily place its center to correspond to the last point of the extrusion path. The circle can be positioned wherever


Lesson 3

you like as the extruded surface is created with reference to the extrusion path and not to the profile.

3) Choose the Pipe function. At the console prompts, select the circle and then the curve you have just drawn, thus building the first portion of the handle.


Building a Teapot

4) To specify the position of the extruded surface according to

the sectional curve, you must activate the Origin option in the Align to section of the Modeling Tool panel.

5) As you did for the spout, use the Intersect CT modeling tool to split the surface. At the program console prompts, select the two intersecting surfaces and type B so that splitting the intersecting surfaces outputs a single object composed of all resulting faces. At the prompt Choose which surfaces will be split, type B.

6) Pick the part of the handle internal to the teapot base while holding the Alt key down. You can then use the Edit4Delete command to delete it.


Lesson 3

7) You now need to plug up the frame. Therefore, you have to

create a cap to place at the end of the tube. First, choose the Edge Extract modeling tool and select the handle surface. Pick the edge you want to extract and press the spacebar to end edges selection.

8) Once you have extracted the circle from the surface, you can

fill it. Choose the FillPath modeling tool and select the circle. Press the Spacebar .


Building a Teapot

9) Create the second bar that serves to hold the handle by first

drawing a NURBS curve.

Then, create a circle of radius 0.2 in the Right view, placing its center in correspondence to the last point of the extrusion path.


Lesson 3


Building a Teapot

Finally, using the Pipe function, create the entire metallic bar.

10) All you are left with is the grip, and you can obtain it by

using a simple Birail function. Draw an ellipse in the Right view and adjust its position in the Front view.


Lesson 3

Then, create two curves as in the pictures below to delineate the shape of the grip itself. Draw both curves starting from the left.


Building a Teapot

11) Select the Birail modeling tool. In the same order, select the circle you have just created, the lower curve (the wavy one), and the upper curve. The result is illustrated in the following pictures. The handle is created with respect to the rails, but you can modify its position by simply adjusting the values of Point on Rail#1 and Point on Rail t#2 to 0.25 and 0.75, respectively.


Lesson 3

12) Select EdgeExtract and the grip surface. When this is green, pick the external curve that is now blue. Upon selection, it turns yellow, indicating that the curve is extracted.


Building a Teapot

13) Ultimately, use FillPath to close the open portion of the grip.


Lesson 3

If you don’t like the lid surface, for example, you can take advantage of the Construction Tree to modify the construction profile. Just select the curve while you are in Object mode, then switch to Edit mode and edit the control points.


Building a Teapot

Learning solidT 25

While you modify the construction curve, the surface is interactively updated.

You have just completed your project! Its form has been fully realized. As you can tell by looking at the picture above, it already grants an optimal representation.

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building a teapot lesson 3 building a teapot · building a teapot 11) select the birail modeling...

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