Graphics Programs Reference
In-Depth Information
have told the particles to follow the empty. Animate the empty to move across the screen
(see Chapter 9 for a refresher on animation). When the animation is played, select the cube
in the 3D window. Particles are emitted from the cube, head towards the empty, and attempt
to follow it as it moves across the screen (Figure 13.64). Having the cube selected displays
the particles as little orange squares; if it isn't selected, all you get are black dots, which are
hard to see.
Note:
With a high particle amount, Blender may crash due to overload when calculat-
ing data. This of course depends on the capability of your computer.
13.11.2 Example: Directing Movement
In this example, I will demonstrate how to direct particles to move from one object to another.
Start a new scene and add a second cube object by pressing Shift + the D key. Note that the
default cube is named “Cube” (see the lower left side of the 3D window) and the new cube is
named “Cube.001.” Position the Cubes as shown in Figure 13.65, scaling the new cube down.
Select the original cube and add a particle system with boids physics. In the “Emission” tab,
reduce the “Amount” value to 10 and set the “Lifetime” value to 1500; we want to keep the
number of particles low and have them visible for a fair amount of time in the animation. Go
to the timeline window and set the animation “End” value to 1500 frames.
Now let's display the particles in a different way. In the “Particles” button - “Display” tab,
select “Cross” and set the “Draw Size” value to 10; you will see a cross appear on the cube. In
the “Boid Brain” tab, remove “Separate” and “Flock” and add “Goal.” Click in the “Object”
box below the rule window and select “Cube.001”—this tells the particles emitted from the
original cube to go and find the target. Play the animation to see the result: crosses emitted
from “Cube” migrate across to and accumulate on the target (Figure 13.66). Remember that
the location of either or both of the cubes in the scene may be animated at the same time.
Figure 13.65
Cube
Cube.001
