Harmony 14 Premium Documentation: Sprite Emitter

Generation Tab

Parameter	Description
Emission	Trigger: An on/off switch using binary code. 1 = on, 0 = off.
	Number of Particles: This is where you can define how many particles will be emitted on each frame.
	Probability of Generating Any Particles: This is a probability percentage between 0 and 100. If the probability is set to 100%, it will generate the Number of Particles specified. If you set the percentage to 50%, then there's only a 50% chance that it will generate the number of particles set in the Number of Particles. You can play with this value to add random spacing to the generation of particles.
Generator	Streak Seed: The number of streaks to generate. Source Sampling Time Offset: Sets the streak start at a different time to offset its position. Source Sampling Duration: This parameter is the key to generating streaks. If set to 0, the behaviour is the same as before. If set to -10 for example, it will sample the input region (in this example the Planar-Region) 10 frames in the past. If in this mode, the Number of Particles parameter is the number of streaks to generate. If you want to generate five streaks for example, you need to set the Streak Size to a value different than 0, otherwise all the streaks will be at the same spot. Source Samples Per Frame: The number of subdivisions for each frame. A value of 1 generates a particle for each frame. A value of 16 generates a particle on each 1/16th of a frame. Streak Size: The radius of the sphere used for sampling the offset of the streak. Region Size for Baked Particle Input: The Baked Particle Input property refers to when you use a Baker as an input to a Sprite Emitter. You can do this when you want to generate particles from other particles. When you do this, you have the option of setting a sphere around the source particle from which the new particle system will generate particles. That is the region which is referred to in this value. If you look at the following example, you'll see that the purple smiley faces are generating smaller green, blue, and yellow smiley faces. This is done by plugging the Baker from the purple smiley faces into the Sprite Emitter of the other smiley faces. See the following images:
Type	You may want to design a variety of different drawings that will vary the appearance of your particle system. To do this, you should put each drawing on its own cell in the drawing layer. Each drawing will then be a new Type of particle. Type Generation Strategy: Lets you sequentially or randomly assign a type (moving from one drawing to the next). Particle Type 0: This is the frame number of the first drawing. If you have a 5-frame cycle that starts on frame 1, you would put a 1 here. Particle Type 1: This is the frame number of the last drawing. If you have a 5-frame cycle that starts on frame 1, you would put 5 here.

Initial Parameters Tab

Parameter	Description
Age	Age at Birth: A different start frame number can be entered in this field. This means that a particle can start with a different drawing than the drawing that you have on frame 1. Age at Birth Standard Deviation: Allows a random deviation for the birth of the particles. If you have a 5-frame cycle that starts on frame 1, but you want the particles to be of a random type, then you may want to set the Age and Birth to 3 with a standard deviation of 2. That means that particles will randomly be born at any frame from 1 to 5.
Age	Set Maximum Lifespan: Makes particles die automatically. Maximum Lifespan: This is how long the particle will exist before dying. Maximum Lifespan Sigma: The lifespan variation of particles. If set to 0, all particles will have the same lifespan. A larger value means that particle lifespans will be distributed over a larger range.
Advanced	Particles Mass: Define a mass for the particles. This mass will affect how the particles interact with gravity. Copy Particle Velocity for Baked Particle Input: If you select this option, the velocity of the parent system will be applied to the child system when a Baker is used as the region for a Sprite Emitter. Add Particle Age for Baked Particle Input: If you select this option, the age of the parent system will be inherited by the child system when a Baker is used as the region for a Sprite Emitter. Align Initial Velocity: This aligns the initial velocity with the region from which the particles are being emitted. If you are emitting from a sphere, then the particles will all start out moving away from the centre of the sphere. Minimum Initial Rotation: Define a minimum rotation in degrees that the particle can have when it is generated. There is also a separate Rotation-Velocity node in which you can define this parameter. Maximum Initial Rotation: Define a maximum rotation in degrees that the particle can have when it is generated.

Rendering Tab

Parameter

Description

Sprite Selection

Rendering Strategy: Select a method to determine the particle type defined for each particle that is created.

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Render as Dot: Renders each particle as a dot. This is useful mainly for previewing the effects of your particle system without using the drawing layer (sprite).

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Use Frame Number: As the frame number increases, the type of particle will change to match the frame number. This means that ALL particles in the system will change together as the frame number changes. If you only have a few drawings, then you may want to enable Cycling to cycle those drawings.

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Use Frame Number as Index in Selector: When you select this option, you can use the Selector to animate the Frame Number it uses over time. So, instead of taking the current frame as the Frame Number, you can write your own function instead. For example, if you animate the selector so that at frame 1, it starts out at 2, then 8 frames later you add another keyframe to set the value to 4. Between frame 1 and frame 8, the particles will all change type together from what they look like on frame 2 to what they look like on frame 4.

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Use Particle Type: Each particle that is generated will look like the Particle Type that was assigned on the Generation tab. For example, if you use a value of 1 for Particle Type 0, and 6 for Particle Type 1, then each particle will be assigned a type from 1 to 6. This type corresponds to the drawing that appears on the sprite on that frame number. So if you have a drawing layer called Sprite that is plugged into the left in-port of the Emitter, it will look for the drawings in cells 1 to 6 of Sprite to assign those drawings to each particle.

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Use Particle Type as Index in Selector: This option allows you to use the Selector to manually create a function that assigns how many of which particle will be created.

For example, you can set the Particle Type to go from 1 to 100 in the Generation tab. Then use the Selector to remap the particle types to a certain drawing. So for example you could create five drawings, labelled 1 to 5, and use the selector to create mainly 1s, no 2s, a few 3s, 4s, and a very few 5s. What it's doing is looking at the X-axis to find what the particle "type" is, then looking at the Y-axis to find out which drawing to assign to that "type." When you use 1 to 100 as a type, then when you're setting the values, they act as a percentage.

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Use Age: As the particle ages, it will change appearance from what appears on the Sprite's first drawing to the subsequent drawings. This means that each particle can have its appearance animated as it gets older.

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Use Age as Index in Selector: You can animate the Selector to change how a particle ages over time. For example, if you have a Sprite with six drawings on it, you might want to animate it so it changes from drawing 1, on frame 1, to drawing 2, on frame 10, then drawing 3 on frame 14, drawing 4 on frame 16, drawing 5 on frame 17, etc. so the particle rapidly ages. This allows you to change the timing of the aging dynamically through the selector, instead of having to modify the exposure of the cells on the Sprite.

Selector: Animates the Selector in conjunction with the Rendering Strategy to adjust the parameters that control the particle’s appearance at birth and over time.

Cycling: If you're using rendering strategies like Frame Number or Age, you may want to cycle the drawings. For example, if you are using Frame Number, but you've only got 5 frames worth of drawings in your Sprite, then if you use "No Cycle," your Particles will disappear after frame 5. You can choose to cycle Normally (1-2-3-4-5-1-2-3-4-5) or Back and Forth (1-2-3-4-5-4-3-2-1).

Number of Drawings in Cycle: Lets you indicate how many frames from your Sprite you'd like to cycle.

Transformation

Size over Age: Lets you determine the size of the particle as it ages. Attach a function to this attribute if you want to, for example, have the particles get smaller as time goes on.

Directional Scale: Scales the particle in the direction of its movement.

Directional Scale Exponent Factor: Sets an exponent here for how much you want that particle to scale.

Align with Direction: Aligns the particle in the direction of its movement.

Axis to Align: Select the axis that you want to align. This axis refers to the axis of the Drawing grid from the Drawing node plugged into the emitter.

Flip X Axis to Match Direction: You may want to have the particle align to the X direction of movement. You can see this property being used in the Lemmings example.

Flip Y Axis to Match Direction: Similar to flipping the X axis, you may want to flip the Y axis of a drawing to match the direction of the particle movement..

Use Rotation of Particle: Enables rotation on the particle.

Keep Volume: When you choose to do a Directional Scale, this will automatically maintain the volume of the particle by squashing it proportionally to how much it stretches as a result of the directional scale.

Colouring

Colouring Strategy: Lets you choose how to define the colour of the particle.

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Use Drawing Colour: The particle remains the same colour as it was drawn with.

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Map RGB Based on Age: Attach a function to this to vary the Red, Green, and Blue values of the particle as it ages.

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Map RGBA Based on Age: Attach a function to this to vary the Red, Green, Blue, and Alpha values of the particle as it ages.

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Apply Opacity Based on Age: Keeps the original RGB values from the drawing, but vary the Alpha (Opacity) according to a function that you define here.

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Map RGB Based on Frame: Changes the Red, Green, and Blue values of the particles based on the frame. Changing based on the frame means that ALL particles will change colour on that frame, regardless of their age.

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Map RGBA Based on Frame: Changes the Red, Green, Blue, and Alpha values of all particles on a given frame by attaching a function.

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Apply Opacity Based on Frame: Uses the original RGB values from your drawing, but varies the Alpha (Opacity) of the particles on a certain frame by attaching a function to this.

Red, Blue, Green, Alpha: This is where you can attach functions to the Red, Blue, Green and Alpha values. You can also click on the colour swatch to adjust the colour.

Compositing

Blur: Lets you determine the Blur to apply to the particles.

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No Blur: No blur will be applied to the particles.

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Directional Blur Based on Age: Attaches a function to define how you want the particles to blur based on the age of each particle. The particle will blur in the direction of movement.

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Directional Blur Based on Frame: Attaches a function to define how all particles should be blurred at a particular frame. The particle will blur in the direction of movement.

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Low Quality Radial Blur Based on Age: Attaches a function to define how you want the particles to blur based on the age of each particle. This will be a low quality blur.

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Low Quality Radial Blur Based on Frame: Attaches a function to define how all particles should be blurred at a particular frame. This will be a low quality blur.

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Low Quality Radial Blur Based on Camera Distance: Defines how you want the particles to blur based on their distance from the camera. This is a low quality blur.

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High Quality Radial Blur Based on Age: Attaches a function to define how you want the particles to blur based on the age of each particle. This is a high quality blur.

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High Quality Radial Blur Based on Frame: Attaches a function to define how all particles should be blurred at a particular frame. This is a high quality blur.

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High Quality Radial Blur Based on Camera Distance: Defines how you want the particles to blur based on their distance from the camera. This is a high quality blur.

Blur Intensity: Lets you set a value or attach a function to animate the blur according to the type of blur that was defined from the drop-down list.

Falloff Rate: The distance where the blur fades from the edge of the image. Select a value between 0 and 1. A falloff rate of 0 causes the blur to fade out slowly, distributing the blur evenly from the edge of the drawing to the farthest edge of the blur. A falloff rate of 1 causes the blur to fade out quickly so that the blur is heaviest at the edge of the drawing.

Blend Mode: Defines a blend mode for the particles to get cool effects.

Blend Intensity: This is a percentage of how opaque you want the particles to be blended. 50 = 50% transparent. 100 = opaque.

Sprite Emitter

Sprite Emitter Properties