EFFECTS

Cristal

 

The Effects->Nebula, Effects->Cometa, Polygon->Mosaic, or Polygon->Breakup. The Cristal effect can be used to make the particles travel through space, strike other objects, bounce off obstacles, or react to wind effects. For example, you can animate particles falling and bouncing off the floor, striking other objects, or moving with the wind or in water.

 

Procedure

  1. Create a polygon mesh object and separate the polygon mesh into particles using another custom effect such as Get->Nebula in the Model module, Effects->Cometa in the Motion module, and Polygon->Mosaic in the Model module, or the Polygon->Breakup in the Model module.
  2. Select the polygon mesh that has been separated into particles. Transform it as desired in your scene.
  3. The particle object must always be frozen before using the Cristal effect. Do this by choosing the Effect->Transformations command in the Model module.
  4. Select the Effects->Cristal command in the Motion module. The Cristal dialogue box is displayed.
  5. Set the parameters as desired and click Ok.
  6. Pick the particle polygon mesh object.
  7. If you selected the Hit Object option in the dialogue box, pick the obstacle polygon mesh. If you did not select the Hit Object option, select the particle polygon mesh again.
  8. Play the animation.

 

Parameters

 

Frame Rate

Number of frames per second for the animation.

Gravity

Simulates a gravitational effect to act upon the particles. The default value is 9.8, which represents the Earth's gravity. Values range between 0 and .

Elasticity

Determines the resilience of a particle after it strikes another object. If the value is set to 0, all the momentum of the particles is lost when they collide with another object (the particle sticks to the object). If the value is set to 1, all the energy of the particle is maintained after the collision (it keeps the same velocity and acceleration it had before striking the object after it bounces off the object).

Air Friction

Simulates the friction caused by a particle moving through a medium. If the value is set to 0, no friction is applied to the particle as it moves through space. Values range between 0 and .

Linear Speed

Sets the initial speed of the particles. The speed of the particles can be controlled along the x, y, and z-axes, and is measured in SOFTIMAGE units per second.

Wind Speed

Simulates a wind effect that acts upon the particles. The wind speed can be set along the x, y, and z axes, and is measured in SOFTIMAGE units per second.

Hit Object

When you select this option, the particles bounce off another object you specify. The object must be a polygon mesh. The object can also be concave, but all its polygons must be convex (with the normals pointing out toward the particles striking the object).

Rotation On

When you select this option, the particles randomly rotate after the first collision.

Flat after Landing

When you select this option, the particles lie flat on the "ground" (see the Ground level option below) after the particles lose momentum and come to rest.

Ground Level

Simulates a limiting plane that represents a floor. When you select this option, the particles bounce as soon as they strike the floor plane that lies parallel to the x and z-axes. You can specify the level of the floor plane anywhere along the y-axis.

Gravity Active Only after First Collision

When you select this option, the Gravity value you set affects the particles only after their first collision against the floor or an obstacle polygon mesh.

Particles Visible Only after First Collision

When you select this option, each particle is visible only after its first collision against the floor or an obstacle polygon mesh.

Wind Uniform until First Collision

If you have specified the wind speed using the Wind speed option, a random value is applied to each particle. This random value causes the polygon mesh object to start breaking up into its constituent polygons (particles) as soon as the simulation starts. When you select the Wind uniform until first collision option, the random value assigned with Wind is the same for all the particles in the polygon mesh. This ensures that the polygon mesh object does not break apart before the first collision.

Repeat

By default, after you have run the animation created with the Cristal effect, you cannot play it back. This is because it is impossible to know in advance what the position of the particles are at a given frame. Therefore, you can only repeat the animation if the Fast playback option is selected in the window's Layout dialogue box.

If you select the Repeat option, the frames of the animation are written to disk. For each frame to be saved, a new file is created which contains the position of the centre of each particle. When the animation is played back, SOFTIMAGE 3D checks if that frame has already been computed, and if it has, the position of the particles is read from the file.

You specify the name and location of the files to be saved in the text box to the right of the Repeat option. The default name and location that is applied to the files is /usr/tmp/Frame.

Save One Frame Out Of

When you select the Repeat option, this Save option specifies which frames in the animation are recorded to disk. For example, assume you want to record an animation which is 10 frames long. If you set this value to 1, every frame in the animation is recorded; if you set the value to 2, frames 1, 3, 5, 7, and 9 are recorded, etc.

Delete Saved Frames after Finished

When you select this option, the files created using the Repeat option are deleted from disk when the Cristal effect is terminated.

Do not select this option if you intend to recreate and render the effect at a later time.

Next, Previous, Delete, Key, and Frame

To animate the effect, Next advances to the next keyframe, Previous goes back to the previous keyframe, Delete removes a keyframe, and Key sets a keyframe at the frame you specify in the Frame text box. These controls can only be accessed after you have set the initial parameters in the dialogue box and clicked Ok. To return to the dialogue box and edit keyframes for the effect, select the effect icon and choose the Effects->Edit Parameters command in the Motion module.

 

Last updated 02-apr-1998