Join Lee Lanier for an in-depth discussion in this video Preparing CG particles, part of VFX Techniques: Creating Particle Effects.
We're now ready to add an evil ray coming out of the evil wizard's wand. This time, though, we're not going to use particles built into after effects, we're going to import a renderer. Let's do that. File Import>File, in the evil ray folder. Inside footage, or grab the evil ray clear sequence and open that. I'm going to make sure it's pre multipled. This is actually rendered in Maya, and then make sure the edges are good quality, need to make sure it's set to pre-multiplied. Then we're going to make a new composition to prepare this.
We'll call this prepRay. Make it the same resolution, frame rate, and duration. We'll drop that new footage in. Let's take a look at that. So this is a Maya dynamic particle simulation that shoots out blobby particles that stick and fall on a stand-in piece of geometry that represents the good wizard. Now that's not ready to go as is. We have to fine tune it, and fit it, and work with the timing. That's not unusual when you're dealing with a renderer that was created outside After Effects. The first thing I want to do is offset the footage.
On frame 14, I want the particles to hit the wizard. That works well with the way the footage is currently cut. So, I'm going to Click+drag the footage to the left until it gets to the correct frame. So, I want it to be like this in frame 14, where the particle blob has hit the person. Starting to creep around the shape, so look for this frame, and make sure that occurs in frame 14. Now we're going to have to rotate and scale and position this, so in anticipation of that, I'm going to move the anchor point by going to the Pan Behind tool, and dragging that anchor point over here to the start.
Let's work with the scale next. It needs to start very small, so on the first frame I'm going to key the scale to 25. By frame 14, I want it to fit the frame. Because in Maya, frame 14 was used as a reference. In terms of where to put the stand-in man, and where to have the particles go. Now this actually created as half resolution, so I need to scale up by 200%. I just need to make sure the position is such that it fits the frame again. So I can use a trick where, with the layer selected, I can Ctrl+Alt+F.
Or Cmd+Alt+F to fit that so it's back at the start position. We're going to go ahead and key the position, turn on the time icon for that. Then what I can do is, animate the first nine frames to make sure it comes down at the wand. Now, to figure that out I need to have the wizard footage in there as reference. I'm going to go back to the build three composition then Ctrl or Cmd+Click the evil wizard, good wizard, and good wizard matte layers. Then copy them, Ctrl or Cmd+Z, then go back and paste those in on frame one, Ctrl or Cmd+V.
And pull this down, go to the layer name. Let's make sure they're in the right order. I actually need the evil wizard on the bottom, good wizard second, and then the good wizard matte, and there they are. Now I can go ahead and finish the position animation on the ray. I'll zoom in close and then drag it up here so it's on the tip of the wand. I just need to do this for the first nine frames. They're going to overlap where the particle starts in the tip of the wand just a little bit.
(SOUND) There we go. Now one odd thing is, this is starting to form a straight line, but it's not oriented the same direction as the wand. It would be great to have some rotation on this also. So I'm going to key the rotation. We'll start at 60 degrees on frame one or the first frame, and then by frame 14, it's back to zero degrees. There we go.
Now frame nine through 14 or so is fine, he's just firing the ray. Now one problem is, the speed the ray gets fired out is pretty slow. So what I"d like to do is speed that up. Now it looks like though, the rotation's a little bit late. So what I'm going to do is, instead of putting that second rotation key on frame 14, I'm going to make it on frame nine. That way when it shoots out, it shoots out straight. In any case though, it's a bit slow at the start here, so what I can do is, add another time warp to this layer. We're going to back up to Layer>Time>Needle Time Remapping.
Let's check out the curve to that. A falling curve means there's no warp, what I could do though is Cmd or Ctrl+click on the curve at frame 14 to insert a new key frame. Then I'll insert a key frame on the first frame. Then what we're going to do is pull the first frame down. What that means is, it's going to dig deeper into the image sequence, closer to the start of the image sequence, and use more of those frames in a sped up fashion. So we pull this down to say ten or as close to ten as we can get, say 10.24.
So we'll speed up that section. And you'll see the frame value right there at the bottom left of that yellow balloon. So let me get it back to you, something close to ten, actually 9.82 is pretty close also. So at that point I'll let go. We'll see at this part of the curve is steeper which means it's using more frames in more rapid fashion, then it goes back to normal speed. Now if I play it back I can see that initial blast is faster. Now since I warped it, I might want to check my position key frame to make sure it's still following the wand.
Looks like it's slipped off a bit. So I should update those keyframes. There we go. Let's work on making this particle ray a little bit more interesting. It's a bit transparent and dull. And add a special effect to stylize it, or go to Effect>Time>Echo.
Echo layers the number of copies of the same footage on top of itself, so what I can do is, set the echo time. Determines the distance between copies to negative 0.02. That's a portion of a second. Then the number of echos that uses the layer three, and then to prevent this from going pure white, I'll change the echo operator, which is like a blending mode to maximum. Now it looks thicker and more interesting. I'll also add a curves effect to adjust the contrast. So another S curve, give it more contrast, (SOUND) something like that.
Now one last thing we might want to do here is maybe mask the particles. Look at a later frame. Especially around, say 25, particles are starting to fall off in circular blobs. Rather have a more continuous mass that sticks to the man. So what I can do is, draw a subtractive mask around this layer to cut away some of that and make it smoother. We'll change that mask to subtract, and then maybe convert it to a roto Bezier so I can smooth it off better. Layer mask and shape path > roto Bezier.
Go back to the Convert Vertex tool and and use that to click drag left or right to smooth out that mask. Now I don't want this tracted mask to be permanent and fixed in one shape, so I need to key frame that over time. So for example I can set a key on frame 20 and I'll probably have to reshape it for that frame. Just cutting off those extra blobs. Then maybe frame 40.
Now to prevent this from being a very static edge, I can move a few points to make it look like it's actually dripping. Or moving downward slowly. And then another key frame at frame 20. I want to sped some time shaping the mask. And then playing it back. And see what it looks like. I'm going to rush through it just for now. I should also feather that so it's a little bit softer on the edge. So a feather of six. There we go. Now, I can also a second mask too. I can draw a mask on the back side to make sure the accumulation of particles doesn't get too thick.
So it will be another subtractive mask. So back to the Pen tool, draw a mask that's a little bit tighter to the back; goes out and comes back. Change that to subtract also. So, on a later frame, starts to cut into that mass. You can slso feather this too. Now, this one doesn't really have to be keyframe, just find a good position for it and leave it there. Now that we've prepped the particles, we can hide the wizard layers. They are just there for reference, so I'm going to turn these off.
So we brought in a Maya render, adjusted the position and the scale and the rotation, add a few effects to prepare those particles for integration into the main composite.
- Setting up the project in After Effects
- Generating a particle blob
- Hand tracking particles into the plate
- Patching the background
- Creating particle puffs, sparkles, and explosions
- Motion tracking elements
- Color grading shots
- Keying green screen
- Layering particles