教程:使用形状图层在Adobe After Effects CC中创建动画低三分之一

在本教程中，我们将看看使用Adobe After Effects CC 2015的形状图层来构建低三分之一的图形. 我将演示如何使用一些简单的技术创建自定义的低三分之一图形.

创建一个新公司

Let's start with getting After Effects open and creating a new composition. Select and adjust your composition settings, so that they match your video project. 完成后，按OK.

绘制并定位一个矩形

Next, we'll navigate to the toolbar and hover over the Rectangle tool. 如果您在过去的项目中使用过此工具，您可能会看到另一个形状. To change this tool back to the Rectangle tool, just select the drop-down arrow and choose rectangle (下面的图1).

图1. Make sure you have the Rectangle tool selected.

激活形状工具, you can now go to your composition window and, 通过点击和拖动, you can start to draw a rectangle. 左右或上下移动鼠标可以完全控制这个矩形的外观. If you're looking to keep your rectangle or any shape you draw proportioned, then you can undo the shape by pressing Command+C (Mac OS) or Control+C (Windows). Now, before drawing the shape, hold down Shift when clicking and dragging.

In this example, I'm just going to draw the custom rectangle shown in 图2(下面).

图2. The custom rectangle we’ll use in this example.

Once you have your shape drawn, select the selection tool to reposition your shape. In this example I'll move the rectangle to the bottom part of my Composition window, as this is the area where my final lower-third will live.

选择填充颜色

You can now begin to further 定制 the shape. 通过在时间轴面板中选择相应图层名称旁边的三角形来打开形状图层的内容(下面的图3).

图3. Opening the contents for the Shape Layer.

Select the Contents drop-down, then Rectangle. Here you can adjust a number of things, including the color of our shape which can be found under Fill (下面的图4).

图4. Adjusting the contents of the rectangle

Open the Fill options and select the color. This will open up the Color dialog box. Here you can pick whatever color you'd like. Use the eyedropper tool to pick an exact color from a logo or a color palette. For this example, I'll select a darker gray color and then press OK.

添加描边

Next, let’s add a stroke around the shape. Collapse the Fill option and open up the Stroke drop-down. 在这里你可以选择描边的颜色，但我将跳过它并调整宽度. Here, I'll enter a value of 25. 现在，你可以看到 图5(下面), the shape has an outer stroke applied to it.

图5. The rectangle with a Fill color selected and Stroke added.

You can continue adjusting options here and really fine-tune your look.

添加一条线

I'll stop there and quickly add a line to the shape. This will help separate a person's name from their title, which is commonly used in lower-third graphics. To add a line, begin by navigating to Layer in the menu, and then choose New > Solid (下面的图6).

图6. To add a line, begin by choosing Layer > New > Solid.

The Solid Settings dialog box opens (下面的图7). 在这个例子中，我将选择一种白色，因为这是我想要的颜色.

图7. The Solid Settings dialog box

Now, press OK and adjust the scale of this new white solid. 在时间轴中选择白色实体图层后，按S键打开缩放属性. Now, deselect the Constrain Proportions option (下面的图8)，并单独调整比例值，直到它们适合矩形形状. This might take some fine-tuning, depending on how you drew your shape.

图8. Deselect the Constrain Proportions option.

最后, 我将调整图层的不透明度，选择它，然后按T键打开不透明度属性. I'll change this value from 100 to 20%. This makes the line a little more subtle, but still offers some separation between the name and the title.

Now, we have a lower-third, shown in 图9(下面)，我们可以在After Effects或其他编辑程序(如Premiere Pro CC)中添加文本.

图9. The shape is ready for us to add 文本.