The presets panel is pretty self explanitory. You select a preset from the combobox and it is applied. Be warned, the preset is applied immediately, so any settings you may have changed are lost. Save stores your current settings in a preset named whatever is currently in the combo box. You can change the names of the presets at any time simply by typing the new name for the currently selected preset in the combo box.

Import is disabled because I'm still working out a good cross-platform way to let you easily import new presets. Export works, but all it does is print the particle settings to the output window in the appropriate format. You can cut and paste the settings into a text file or use it to easily post settings on a web site, etc. These will be fully functional by v2.5, but since I'm working on this in my spare time, that may be a while.

Emitter Type: The radio buttons allow selection between emitter types. The difference between emitter types is as follows:

     Point - Emits particles in a stream from a single x,y position on the stage.
     Line - Emits particles from random positions along a line, which will be shown on the stage at design time by an orange line extending the width of the emission area.
     Area - Emits particles from random positions within a given area, which is shown at design time by an orange bounding box surrounding the emission area.

Active: Whether or not the emitter is currently active. You can keyframe animate this component by turning the emitter on and off to synchronize particle effects to events in your movie.

Visible: Whether or not the emitter is visible when the movie is published. Leaving the emitter visible can be beneficial during development for precise placement, but this allows you to make the emitter visible during development and invisible when you publish.

Prefix: This is the first letter of the name of each of the particle instances created, for example: p1, p2, p3, p4, etc. The purpose for this control is to allow you to change the name of the particles generated by different instances of the component on the stage, so that there are no naming conflicts when layering multiple emitters for an effect.

Level: Similar to the prefix setting, this allows you to have different emitters running on the stage at the same time without having depth conflicts. Because there are more than 65k levels available in Flash, I generally set the level to 1000, and then don't place anything between 1000-1999 to be safe, but realistically you will never be able to generate 1000 particles without seriously slowing down any computer that tries to play it back.

Width/Height: This is the width and height attribute of the bounding box for the line and area emitters. My plan was to let you set the width and height by scaling the emitter on the stage, but the MX 2004 live preview made that almost impossible, so this is what you get instead.

Particle Type: This is the list of available particle types. Still no luck with the real-time SVG import (SVG files are big), so while I'm working out a way to do this properly, you're stuck with my built in particle types or any movie clip in the library with an export name. To use your own artwork, convert it to a movie clip and set it to export on the first frame. In the particle types combobox, select "Custom Particle" and then type your particle's export name into the Linkage Name box.

Rate: This is the rate at which particles are spawned, per frame. Always start with one, because if you have 10 particles spawning per frame, and they live for 100 frames, you may have as many as 1000 particles on the stage at once, which will cause flash to run very slowly.

Orientation: This is the orientation (starting rotation) of the particle. The possible settings are:

• World - Default, and probably the setting you will use most often. Aligned to the stage. In other words, the particle will face the direction the artwork faces.
• Emitter - This aligns the particle to the emitter, so if the emitter has been rotated 90 degrees, the particles will spawn rotated 90 degrees.
• Random - This starts each particle at a random rotation, which is useful for giving the illusion of each particle being different.
• Arbitrary - This setting allows you to manually enter an orientation, in the spinner box next to the combo box. This is for cases when the artwork was generated facing one direction, but needs to face a different direction as a particle. Possible values are 0-360.

Life: This is the number of frames the particle will live. You generally want the particles to live only as long as absolutely necessary, for example until they pass off the stage or until their opacity fades to 0. Remember, the longer they live, the more particles you will have on the stage at one time, which is the main cause of frame rates dropping.

Life Variation: This setting allows you to introduce randomness to the life attribute. It is a percentage, so a value of 25 would mean that the life setting may vary by +- 25%. Be warned, using life variation may cause particles to die unexpectedly, as new particles overtake their names or depths.

The following controls are custom components I built specifically for ElementalFX. The gradietns represent the life of the particle, from 0% (birth) at the left to 100% (death) at the right. The gradient between shows the variation in size across time. In the image to the left, the size setting has a value of "100% at birth, gradually scaling down to 0% at death". I found that this kind of value was too difficult to express with numbers in a settings panel, so I created these gradient controls (remenicsent of discreet Combustion) to simplify the settings.

Size: Size of the particle over time, in percent (0-100).

Size Variation: Percent variation in size.

Opacity: Opacity (alpha) of the particle over time, in percent (0-100).

Opacity Variation: Percent variation in opacity.

Color: This is the color (for vectored particles, using setRGB) or tint (for rastered or custom particles using setTransform) of the particle over time. In the example to the left, the particle will start as red, gradually turning green by it's half-life, and then gradually to blue before it dies.

Tint Amount: This was one of the more complex features to implement, but one of the least useful at this time. In Flash terms, this is like setting the % in the movie clip tint dialog, only all three (R,G,B) values are set to the same percentage, which is what makes it difficult to use right now. In my next point release I will put seperate R, G, and B Amount boxes in there, allowing you greater control over how the artwork is tinted, as well as seperate R, G, and B color values (0-255) instead of a single hex value. This will afford greater flexibility in tinting particles, and since I've already done the hard part, it will be an easy feature to add. In the mean time, my suggestion is to leave it at 0 (do not tint the particle at all) or 100 (tint the particle with the color specified).

Gravity: This is exactly what it sounds like, downward force applied according to physics. The scale is rather arbitrary, so some experimentation is necessary to find exactly the right setting for your scene.

Spread: This is the amount of random spread in the emission pattern, in degrees. At 0 the particles will all be emitted at exactly the same angle, directly out from the emitter. At 15, you get a 15 degree cone of emission, meaning the particles will be emitted at a random angle within 15 degrees of center. At 360, particles will be emitted in every direction.

Velocity: This is the "speed" at which the particles are emitted.

Velocity Variation: Percent variation in velocity.

Spin: This setting causes the particles to rotate on their center. The setting is in degrees and is randomized in direction (clockwise or counter-clockwise).

Spin Variation: Percent variation in spin.

Bubble: This is bubble motion, or a horizontal waveform applied to the motion of the particles. The bubble setting defines the amplitude of the wave, so at a low setting (1 or 2) you will get fast moving, jiggly bubles, while at a higher setting you will get bubbles that slowly sway back and forth. This is useful for both bubbles underwater and snow falling.

Bubble Variation: Percent variation in bubble amplitude.

There is really only one method that the emitter exposes, called KillAllParticles(). It basically does what it says, which is destroy all the particles belonging to a particular emitter. This is necessary because the particles live independantly of the emitter, so simply taking the emitter off the stage does not kill the particles, they will continue to live and move until they reach the end of their life or until the KillAllParticles method of their emitter has been called. The usage is as below.

• Non-Unique Instance Names Share Settings- If two emitters have the same instance name, then they apparently share an XCH object (which Flash uses to pass data between a custom ui, live preview movie, and the run-time component), which basically means they share the same settings. Any changes made to an emitter will affect all other emitters with the same instance name. When a component doesn't have an instance name, it actually still has one but it is an automatically generated name like "instance01", "instance02", etc, which keeps this problem from showing up. But if you name your instances, make sure you give them unique names.
  All Live Previews Use The Current Settings - Apparently, the live preview of all components of the same type assume the properties of the one that is currently selected, which has something to do with the XCH object. So if you have a point emitter and an area emitter on the stage at the same time, and the point emitter is selected, they will both look like point emitters in the live preview. But then if you select the area emitter, they will both turn into area emitters with the same width and height. So far I have been unable to find a way to keep this from happening. However, it doesn't affect the performance of the particle system, only the appearance of the live preview for all particle emitters on the stage at the time. If anyone has any ideas about how to overcome this little "feature" I would love to know about it.

• Preset List Fonts Shrink/Preset List Is Acting Whacky - That is because those are home made, super-light listboxes that I made (inline, not as a component) specifically for the custom UI for this component. I'm improving these listboxes with each release, but there are still some bugs that show up in the Preset listbox. I had to roll my own because when I tried to use the MM listbox component, my custom ui ended up being something like 300k, and took over 10 seconds to load when you selected an instance of the component on the stage. I obviously couldn't have that, so I built a listbox from scratch with the absolute minimum functionality in order to save on file size. They honestly aren't even listboxes, they're ultra-light hacks that sort of look and act like listboxes. : )