3ds Max 2012 Bible - Kelly L. Murdock [442]
3. With the Super Spray icon selected, open the Modify panel, and in the Basic Parameters rollout, set the Off Axis and Off Plane Spread values to 40.
4. In the Particle Generation rollout, keep the default Rate and Speed values, but set the Speed Variation to 50 to alter the speed of the various particles. Set the Particle Size to 20.
5. In the Particle Type rollout, select the MetaParticles option, set the Tension value to 1, and make sure that the Automatic Coarseness option is selected.
6. Open the Material Editor (by pressing the M key), and drag the Purple Soda material to the particle system icon.
Figure 41.9 shows a rendered image of the MetaParticles spilling from a soda can at frame 25.
FIGURE 41.9
MetaParticles emitting from the opening of a soda can
Instanced Geometry
Using the Particle Type rollout, you can select an object to use as the particle. If the Instanced Geometry option is selected as the particle type, you can select an object to use as the particle. To choose an object to use as a particle, click the Pick Object button and then select an object from the viewport. If the Use Subtree Also option is selected, then all child objects are also included.
Caution
Using complicated objects as particles can slow down a system and increase the rendering time. •
The Animation Offset Keying option determines how an animated object that is selected as the particle is animated. The None option animates all objects the same, regardless of when they are born. The Birth option starts the animation for each object when it is created, and the Random option offsets the timing randomly based on the Frame Offset value. For example, if you have selected an animated bee that flaps its wings as the particle, and you select None as the Animation Offset Keying option, all the bees flap their wings in concert. Selecting the Birth option instead starts them flapping their wings when they are born, and selecting Random offsets each instance differently.
For materials, the Time and Distance values determine the number of frames or the distance traveled before a particle is completely mapped. You can apply materials to the icon that appears when the particle system is created. The Get Material From button lets you select the object from which to get the material. The options include the icon and the Instanced Geometry.
Rotation and Collision rollout
In the Rotation and Collision rollout is an option to enable interparticle collisions. This option causes objects to bounce away from one another when their object boundaries overlap.
The Rotation and Collision rollout, shown in Figure 41.10, contains several controls to alter the rotation of individual particles. The Spin Time is the number of frames required to rotate a full revolution. The Phase value is the initial rotation of the particle. You can vary both of these values with Variation values.
Note
The Rotation and Collision rollout options also can increase the rendering time of a scene. •
You also can set the axis about which the particles rotate. Options include Random, Direction of Travel/MBlur, and User Defined. The Stretch value under the Direction of Travel option causes the object to elongate in the direction of travel. The User Defined option lets you specify the degrees of rotation about each axis.
Interparticle collisions are computationally intensive and can easily be enabled or disabled with the Enable option. You also can set how often the collisions are calculated. The Bounce value determines the speed of particles after collisions as a percentage of their collision speed. You can vary the amount of Bounce with the Variation value.
FIGURE 41.10
The Rotation and Collision rollout options can control how objects collide with one another.
Tutorial: Basketball shooting practice
When an entire team is warming up before a basketball game, the space