Using the Particle Operation - Particle Emission

In this tutorial we will describe how to use the Particle operation to "emit" particles.

This tutorial assumes familiarity with 3D Canvas and that the 3D Canvas Basics tutorial has been completed.

bulletDrag and drop two cubes onto your scene as shown.

 

 
bullet Animate the leftmost cube as shown.

This cube is going to be our "source particle". It will be duplicated and "emitted" along this path.
 

 
bulletWhile still in animation mode, select the leftmost cube and right-click the Particle operation. This will open the Particle operation's options window.

Click the Default button.

Enter a Generation Frequency of .1. This means that 1/10th of a particle should be generated per key-frame. A default 3D Canvas scene has 10 key-frames per second, so that means 1 particle will be generated every second. That's a very small number of particles, but it makes a good example.

Enter a Generation Duration of 100, meaning that particles should be generated for a period of 100 key-frames.

Enter a Life Span of 100 to 100. This means that a particles generated will have a life span of 100 key-frames (minimum of 100, maximum of 100).
 

 
bulletWhile still in animation mode, select the leftmost cube and click the Particle operation. Be sure that you are at animation key-frame 0 by clicking before applying the Particle operation.

Click the animation Play button to play the animation.

Particles are generated every second of the animation.

Looking at this animation it is a little bit hard to see what exactly is happening.

 
bulletSwitch back to non-animation mode and drag and drop a cube on to the "particle" as shown.

Return to animation mode.
 

 
bulletClick the animation Play button to play the animation.

This may make what is happening more clear.  The "source" particle is being "emitted" along the animation path at a rate of one particle per second.

At this point we have not defined what the particles should do when they are emitted, so they are just "dropped" along the path.

 
bulletBe sure that you are at animation key-frame 0 by clicking . Select the particle and click the Operation Layer Panel's Update button.

This opens the Particle operation's parameters for this particle.

Enter values of -90 to -90 in the Initial section's Scale X, Scale Y and Scale Z.

The Initial section is used to apply effects to a particle to set an "initial state" for each particle as they are generated. The first number is the minimum amount and the second number is the maximum amount. 3D Canvas will generate particles with random values within this range.

In this case we want particles to be scaled by -90% when they are created. -90 to -90 indicates that we wanted a fixed particle size. If we had said -90 to 0 we would get particles randomly scaled between 0% and -90%.

Click OK.


 
 
bulletThe "Initial" amount is applied immediately to the source particle.

 
bulletClick the animation Play button to play the animation.

Now the particles generated are all 1/10th (-90%) of the source particle's size.
 

 
bulletSelect the particle and click the Operation Layer Panel's Update button. If you find the particle is too small to select, you can select it using the Object Hierarchy.

Enter a Generation Frequency of 1. This means that one particle should be generated per key frame. A default 3D Canvas scene has 10 key-frames per second, so that means 10 particles per second.

Click OK.

 
bulletClick the animation Play button to play the animation.

Now the particles are generated in a steady stream of 10 particles per second.
 

 
bulletSelect the particle and click the Operation Layer Panel's Update button.

Enter a Life Span of 0 to 100. When 3D Canvas creates the particles it will give each one a random lifespan of between 0 and 100 key-frames.

 
bulletClick the animation Play button to play the animation.

The stream of particles is no longer steady since some particles are dying earlier than others.

 

 
bulletSelect the particle and click the Operation Layer Panel's Update button.

Enter values of 5 to 5 for the Scale Y option of the Velocity section. The Velocity section defines how the particle should behave while it is alive. Scale Y values of 5 to 5 indicates that the particle should be scaled 5% per key frame during the particle's life. Negative values for this and the other scaling parameters are a good way to have a particle "fade" (get smaller) and then disappear as it dies.

 
bulletClick the animation Play button to play the animation.

 
bulletNotice that when the particles are emitted on an up slope or down slope they are oriented as though the are following the path. This is intended behaviour which we will cover later in this tutorial.

 
bulletSwitch to non-animation mode.

Move the non-particle cube as shown, select the front face and apply a Tip operation. This is our "rocket".

Use the hierarchy to name your particle "Particle" and your rocket "Rocket". Move the rocket object to the same group as the particle using the hierarchy.

 
bulletReturn to animation mode, select the rocket and click the button on the animation toolbar to reset the animation of the group.

Re-animate the rocket as shown, ensuring that you orient the rocket for the up slope and down slope.
 
bulletSelect the particle and click the Operation Layer Panel's Update button.

Enter a particle Life Span of between 50 and 100.

Enter Velocity scale values of 5 to 5 for Scale X, Scale Y, Scale Z to indicate that the particle should scaled by 5% each key-frame.

Enter a Translate Z amount of -.1 to -.1 for the Velocity section. This indicates that the Z velocity of the generated particles should be -.1 units/key-frame.

 
bulletClick the animation Play button to play the animation.

Think of these particles as puffs of smoke.

 
bulletThe particles are emitted along the path of the animation so they travel in the expected direction as the die/dissipate.

 
bulletSwitch back to non-animation mode and paint the particle a translucent color.

 
bulletReturn to animation mode and play the animation. This is much more smoke-like.

 
bulletFurther refinements that we can make to the smoke include:

A Translate Z velocity range of -.2 to -.1 makes it so that the particles travel at a varying speed.

Translate X and Translate Y velocities of between -.03 and .03 so that the particles not only travel away from the emitting rocket, but also dissipate.

A Scale velocity of 2 to 5 results in puffs that vary in size.

A Translucent Velocity of 5 to 10 ensures that the particles become more translucent over time and do not appear to "pop" when they disappear. Note that a particle that does not have a Translucent value for its material cannot be made Translucent using this velocity. This is a scale factor, so there must be a translucency amount to scale.

A Life Span of 25 to 50 to shorten the smoke trail.

A Generation Frequency of 5 to have more dense smoke. Note that you should always use very low numbers for Generation Frequency when developing a particle animation since increasing the generation frequency dramatically slows the animation.
 

 
bulletOur completed smoke trail.

In this example we used a cube as our "particle". This isn't the best choice for particles normally since it is a very identifiable shape. The key point to remember in creating particles is the that the less points in the particle the better. Complex particles mean slow rendering.

Further refinements can be made by adding an acceleration to the particle. If you have particles being expelled from a location, you may want them to slow down as though they are affected by the air. You can do this by setting the Translate Z amount to a positive number in the Acceleration section.