Loft Tool Use
The Skinning/Lofting tutorial provides tips for improving your effectiveness for creating free-form, organic objects and characters. In addition to showing you how to use the Loft tool, you will also be given tips on removing vertices and on duplicating, re-sizing, and reshaping a 3D form.
Skinning/Lofting
Skinning is the best method for modeling most things. It uses a series of splines as a framework and then connects them in the order that you choose to make a 3D form. The splines can be open like single lines or closed like an oval or rectangle. For this example, you will use closed splines.
- Click on the color swatch and select a color.
- Using the Oval Tool, draw an oval in the Top window.
- Press S on the keyboard to get the selection tool (arrow). Click with it in a blank area of the Top view so that nothing is selected.
- Click on the outline of the oval that you just created. It should now be in reshape mode and display 8 white vertices. You only need 4 of these, so to save memory and make reshaping easier, always delete the following four.
Removing Vertices
- Select the Minus Pen Tool by clicking and holding down the Plus Pen Tool (4th one down on the right). While clicking and holding down the Plus Pen Tool, you should see the Minus Pen Tool pop up.
- Once you have selected the Minus Pen Tool, then imagine the oval as a clock and click on the following vertices to delete them: at 1:30, 4:30, 7:30 and 10:30. You should now only have vertices at 12, 3, 6 and 9.
Duplicating a Shape
- Click in the Groups palette to select the name of the oval that you just drew. It should be called ellipse. Once you have selected the oval in the Groups Palette, the reshape mode will be turned off because the empty vertices disappear and instead, black selection squares show up at the corners.
- Press S on the keyboard to get the selection arrow. In the Front Window click the Fit to View button at the bottom (small square).
- In the Front window, click on the line that is the oval and after you start to drag it down, press the Option and Shift keys down.
NOTE: The Option key will make a duplicate, while the Shift key constrains the dragged duplicate shape to a straight line.
Reducing the Size of the Shape
NOTE: After you have dragged the duplicate shape down in the Front window, you can make the view smaller by clicking the little mountains button and then you can drag it down even further from the original.
TIP: Remember to press the Shift key down after you start to drag the oval, so that it will move in a straight line.
- Once you are finished dragging the second oval, the press Command T or go to the Operations menu and select Transform...
- In the Transform dialogue box, under Resize on the bottom left, type in .5 for the x axis. Since the Same box is turned on (has an x in it), the size will be .5 for all three axes.
- Under Center of Transform: select Center Object(s) from the pop-up button.
- From now on whenever you transform an object, choose Center Object(s) for Center of Transform:
- Click OK.
NOTE: The second oval should now be half the size of the first one and also centered right under it in the Top view.
Making the Final Duplicate Shape
- Press and hold the Spacebar down and in the Front view, click and drag up to move the view of the 2 ovals to the top of the front window.
- While the second oval is selected (if it is not selected, then click on its name in the Groups palette), click on it in the Front view and drag it down and after you start to drag it down, press the Option and Shift keys down to make the 3rd duplicate.
- Press Command T to get the Transform box and reduce this oval by .5. The number from the last Transform should still be there as well as the Center of Transform:
NOTE: Your 3 ovals might now look somewhat like those in Illustration 11.
Illustration 11 - Skin/Loft Step 1
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Skinning/Lofting the 3 Ovals
The order that you select the ovals will determine the final 3D form. In this case, you will just select them starting at the top and work down.
- In the Front view, click the top oval to select it.
- While pressing and holding the Shift key down, select the second and third ovals in that order.
- Press Shift O or click the Loft/Skin Tool. You should notice that the top oval and the middle one have lines connecting them (Illustration 12).
Illustration 12 - Skin/Loft Step 2
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- Now, look at the top of your screen where the Loft/Skin Info palette is displayed (Illustration 13).
Illustration 13 - The Loft/Skin Info Palette
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NOTE: The palette gives you several choices.
- The first 2 buttons on the left allow you to go to the next shape to connect it or go back to a previous one if you need to make any changes before clicking the Done button.
- The Shift Left and Shift Right buttons allow you to rotate the connecting lines.
- The Reverse button connects opposite vertices to each other. You only use these when connecting lines are scrambled and the resulting 3D form looks twisted.
- The Evenly button is used only when the program adds an extra vertex to the next connected shape. It makes sure that only the existing vertices are used. Always loft/skin shapes that have the same amount of vertices.
NOTE: If you skin between shapes that each have different amounts of vertices, then the results can be unpredictable.
- The box labeled Circular is only checked when you want the last shape to connect back to the beginning shape.
- The Smooth option is for getting connecting splines that can be rounded by dragging their direction points. Usually, you would leave this option on because you want to be able to reshape your splines. If you are connecting 2D shapes to make a form with straight lines like a box, then turn this option off.
- Click the Next button in the Loft/Skin Info Palette to connect to the 3rd oval. It should now look like Illustration 14.
Illustration 14 - Skin/Loft Step 3
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- Click the Done button to complete the skinning process.
- The resulting 3D form should now look somewhat like the one in Illustration 15.
Illustration 15 - Skin/Loft Step 4
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Reshaping a 3D Form
- Press S on the keyboard to get the single arrow and select the 3D form by clicking first in a blank area of a window to deselect the object and then click on one of its lines in any window to select the object so that it is in reshape mode.
- Select the very top four vertices by drawing a selection marquee around them in the front window (Illustration 16).
Illustration 16 - Selecting vertices
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- Press the Space Bar key down and then the Command key by holding both keys down you will get the magnifying glass. Use it to get a close up of the selected vertices by dragging around them in the front and top windows. Notice they are filled while the un-selected ones are hollow.
- Select the Resize Tool located as the 3rd one down from the top left. It has a smaller square with an arrow and a larger dotted square icon.
- At the very top of the screen you should now see a horizontal tool info palette. Next to the word Anchor: click on the pop-up menu that currently says User Defined Point and select Selected Vertex(s).
- In the top window click on the top filled vertices and drag down. While dragging down press the Shift key down to constrain the tool to only one axis. Drag down until you see the top oval shape close up into a straight line.
- Now click on the far right selected vertices in the top window and drag to the left while holding the Shift key down until all the selected vertices close up so they look like they've been squashed together.
- Press the Command and Space bar keys down at the same time to get the magnifying glass and use it to get a close up of the selected vertices in the front window. If you see that the selected vertices aren't together tight enough, then click on the far right one and drag it to the left.
- Repeat the same previous steps to close up the bottom vertices of the 3D form.
- Remember to use the single arrow first to select all four of them before using the Resize Tool.
- You can access the arrow by pressing and keeping the Command key down.
- When you're done using the arrow to select the vertices, let go of the Command key and you will still have the re-size tool.
Next, you will reshape the form using the control points of selected vertices.
- Press S on the keyboard to get the single arrow.
- In the front window click on the right angled vertical line (spline) next to the bottom vertices that you just closed up.
- Use the magnifying glass to zoom in or out until you see a hollow diamond shape control point near the very bottom vertices. The control point will most likely be located very close or almost on top of the bottom vertices.
- In order to select the control point instead of the vertices, press the Control key down while clicking on the control point and drag to the right until the spline becomes more rounded (Illustration 17).
Illustration 17 - Reshaping a spline
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- Now, in the Front window, with the single arrow, click on the left angled vertical line (spline) next to the bottom vertices and drag the control point to the left until the spline becomes more rounded. Use the Control key if you have trouble selecting the control point.
- Get a close-up of the bottom of the form in the Right window and reshape the left and right vertices so they are more rounded.
- Repeat this process with the top of the form.