The emitter is an incredibly versatile tool you can use to make a ton of different effects really easy. I wanted to include some vines in a title sequence for a documentary I’m working on, so started off using the Replicator, but it wasn’t giving me the effect I wanted. So here’s how I made realistic vines using the emitter instead.
Create the leaves.
- Hit “b” to bring up the b-spline tool, and draw two leaves, like so:
- Hit Apple-4 to bring up the layers sidebar, and select “Group”. Hit “e” to create the particles.
Customize the emitter.
- Go to the inspector tab for the emitter.
- Change the Life to 20, so the particles live forever.
- Change the Speed to 0, so the particles don’t move.
- Change the Color Mode to “Pick from Range,” so there will be a variety of colors of leaves. Change the gradient so one side is a darkish green, and the other a darker green. The emitter will choose a green from this gradient for each leaf.
Make the leaves appear.
- Because the speed is 0, the particles won’t move once they are emitted. So, in order to have new ones appear, we will need to move the emitter.
- Click on the Emitter layer, and add the Behavior “Motion Path,” which is in the “Basic Motion” submenu. A straight red line will appear. Reposition the line and leaves at the left side like this:
- Now, Alt-Click the line to create a new control point. Drag this to make a nice flowy vine-like vine.
- Play back. Whoops- there are way too many leaves being made, making it a solid line. We’ll need to take the Emitter’s Birth rate down to 2.
- Play back- it’s better, but the leaves are almost too big. Again, in the Emitter’s Inspector tab, take down the Scale to where the vine looks more realistic. This will really depend on the leaves you drew at the beginning, so play around. Here’s what we have so far:
Make the leaves grow.
- But we want the leaves to grow, not just appear like they do right now. Luckily, the emitter has a behavior for this. Select the Emitter layer again, and add the Behavior “Scale over Life” from the Particles submenu.
- In the Inspector, a new control for “Scale over life” will appear. Change the increment type to Custom. Click on the little arrow to make the graph show up.
- We want the leaves to grow fast, then taper off. There are two lines on the graph, one for the particles’ x-scale, and the other for the y-scale, so make sure you’re getting both about the same. Click on the line to create a new point on each line, and drag it to about 15% on the X-axis, and 85% on the Y-axis. Now, select the points by dragging a selection box over them, and right click them, and choose Interpolation- Continuous. This will smooth out the point.
- Play back- you should get this:
Add the vine
- The leaves seem out of place, and need a vine to hold them together. Hit “c” to draw a small circle, about the size you want the vine.
- Select the circle layer, and hit “e” to make particles.
- Again, set the Life to 20, and the Speed to 0.
- Set the Color Mode to “Colorize”, and set that to a dark green.
- Right below that is the Opacity Over Life function- we want it to start transparent, then quickly fade in. Make it look like this:
- Move the Vine emitter to the right between the two leaves.
- In the layers tab, select the Motion Path behavior from the Leaf Emitter, and hit “Apple-C” to copy it. Now, click on the vine emitter and hit “Apple-V” to paste it there.
- Play it back. It should look like this. You may need to move the Vine Emitter so it matches up better to the leaves.
- To see the project file to this point, right click and save this Motion 3 file.
Spice it up
- It looks pretty good, but you can spice it up a bit.
- I added a bit of a more organic look on the Leaves Emitter, adding some Birth Rate Random (very slight), Angle Random, and Scale Random. I also keyframed the Angle so that the leaves would go along more with the vine.
- To see the final project file, right click and save this Motion 3 file.