Drawing lines and shapes in Motion is pretty fun and flexible. But what about animating those lines? Well, it's actually pretty easy, although there are some tricks to be aware of. I'm doing a very simple line drawing here, but you can use these same techniques to manipulate more complex parameters in very complex ways. Let's take a look at how to do this.
We will launch Motion 5 and select a generic Motion project at 720p, 30 fps. I'll name the default Group to 'Boat Group'. I'll use Shift-Command-N to create a new group above that one and name it 'Water Group'.
Select the Boat Group so our boat drawings will reside inside of that group. I'll use the rectangle drawing tool to create some squares for the boat housing, and the bezier drawing tool to create the boat body. F1 to the Shape tab and change the outlines and fills to match up. Building this all inside of our Boat Group will allow us to manipulate the Group as a whole, thus the boat as a single object.
I'll turn off the Boat Group's visibility check box for now. Select the Water Group so our water drawings will reside inside of that group. Using the bezier drawing tool I'll create a rough sawtooth shape for our water surface. I'm drawing only a sawtooth line, but not closing it. I'll hit Enter to finish it off. F1 to the Shape tab to turn off the fill, set Outline to blue and about 10 points for the Width parameter. Then to the Geometry tab to adjust the Roundness to about 20.
There are two ways to animate the water. The hard way is to manually set keyframes. But I'm not here to show you the slow hard way. I'm here to show you the quick easy way. In the Geometry tab, looking at the Roundness setting, Control-click (or right-click) directly on the word 'Roundness', go to Add Parameter Behavior, and select Oscillate. We can set the Wave Shape to Sawtooth, Amplitude to 50, Speed to 30, and turn on the Half Range checkbox. This is a good starting place, adjust to taste.
Now we will have the boat rock to match the waves. Turn on the Boat Group's visibility and highlight it. F1 to the Properties tab, open the Rotation section so that you can see the 'Z' rotation parameter by itself. Control-click (or right-click) on the 'Z' title for the parameter, and Add Parameter Behavior, then chose Link. You'll automatically be put in to the Behaviors tab to adjust the Link behavior.
From the Water Group, drag the Bezier shape you drew for the water into the Source Object well. For Source Parameter, click the Compatible Parameters menu and select Object, then Shape, then Roundness. Adjust the Scale to about 0.25 and adjust the Roundness Offset so the boat rocks upright and level-ish.
With the playhead at the start of the timeline, move the Boat Group to the edge of the frame it needs to start in. F1 for the Properties tab, click the keyframe diamond to the right of the Position parameter. Move the playhead to the end of the timeline, then move the Boat Group to the opposite side of the frame. The new keyframe should get set automatically.
I told you I was here to show you the quick easy way to animate that water. But I'll go ahead and show you the longer more time consuming way to do it. This can be worth it depending on the animations you need to do with your lines.
Command with the Minus key (-) to zoom out of the canvas window. Let's turn off the visibility of the water line we already drew. With the Water Group highlighted, I'll use the bezier drawing tool to make the water again, but this time I'll draw sides and a bottom to the shape that sit outside of my video frame. This time I'm closing it off.
Start with the playhead at the beginning of the timeline. F4 to get to the Shape tab, go to the Geometry tab, and click the keyframe animation diamond to the right of the Control Points parameter title, to create a new keyframe here. Remember that this parameter does not automatically create new keyframes. Move the playhead a second or two along the timeline. Click the diamond to create another Control Points keyframe. Then with the Edit Points tool active (tool menu to the left of the Tool Bar) readjust the wave points. Move the playhead another second or do along, create a new keyframe manually, adjust wave points. Repeat as needed.
Drawing and combining lines in Motion is easy enough. But when it comes to animating them it's super simple. Manually keyframe them with the Edit Points tool. Or use a Shape or Parameter Behavior. I hope some of these tricks will help you to bring your own more complex projects to life.