Modeling the shape

Level: Beginner/Medium

This tutorial starts with creating a simple revolve, then texturing the result into a realistic pot. We make use of the Scope feature to show how to clip an image onto a surface that is already textured.

Start with a new project and select the front view, turn off perspective and reset the view.

Front View
Parallel View
Reset View
The Finished Pot

In the NURBS tab, click the Curve icon. In the control bar select Polygonal curve by clicking the Order icon, and then select Polygonal from the drop down list. Leave all the options at their default settings - we want to draw an axis vertically that we can sweep our pot around. Start the curve at the lower middle of the view window; click once, then make another mouse click straight up the view and towards the top so the line is roughly vertical. (Holding the SHIFT key will keep your line vertical.)

If you keep clicking at this point the curve can be made more complicated - but all we need is an axis so we will accept the curve at this point by pressing the Accept button in the toolbar (you can also right click and select accept from the pop-up menu). This finishes the creation of the curve.

Accept button

To simplify matters - it is always a good idea to name your objects. Under the select window, we can see that we have created a nurbs curve. By slowly double clicking the name next to the nurbs icon we can rename the object. Call it 'Axis'.

We now want to create the "Profile" of the pot. Think of this as a section through half of the pot that is 'swept' around our axis. Firstly though, we must select our axis - make sure it is highlighted before continuing. Under our NURBS tab again, click the Curve tool and select Cubic this time from the Order drop down list. (Polygonal curves have sharp edges - quadric and cubic curves are very smooth.)

We are going to use the axis curve we created as a point to rotate about when we make our profile. To do this, we need to select "Rotate" under our toolbar - click the Pen option to see the different methods - select Rotate.

Starting at right hand side of our axis, click points from the base upwards to create a profile curve similar to the one shown. Each red point represents a mouse click. To get sharp edges in a nurbs curve, we need to put the points closer together. Hence the top has three closely grouped points. Note too that the curve draws both the outside, then goes inside the pot as well.

Do not worry too much about how accurately you place the points - you can edit them later. Notice too how you can see the creation of the revolve.

When you have finished creating all the points, click the Accept button again to finish creating the profile.

Accept

The shape of your pot profile

Notice now that our level structure has changed and we now have a mesh in the view. We created the mesh by rotating our profile curve about the axis. The two curves are now put 'under' the mesh. Press the "+" icon next to the mesh to see the curves below. By editing these curves now will change the shape of our resultant mesh. Rename our nurbs curve to 'Profile'. Note that a mesh is a 3D surface - so when we render the image this is what we will see. Generally, curves by themselves are not rendered.

Rename the mesh to 'Pot'. Let's tweak the profile curve a bit. Select the profile curve, under the context sensitive toolbar a series of options are shown that we can do to this particular curve. Click the Edit button and we will move some points around to create the shape we want.

Edit

If you move the mouse cursor over any single point, the cursor changes to a cross. This means that you can now click on the point and move it around. Do this for each point until it looks roughly like the above image and has an even space between the inside and outside. You can now pan around the view and examine the pot you have created.

To get a better feel for the shape - turn on Open GL view to see the mesh better.

You can also raytrace the view by pressing teh render button in the view control bar.

This is a good point to save your work. Under the File pull down menu, select Save As. Select the appropriate directory by clicking the '...' button next to the name field and Save the file as Pot_Part1.