Making a "sparkles" emitter from scratch    08 May 01



(Note: the Illusion 2 project files and images used here can be found at the end of the 2nd page of the tutorial, and CAN be loaded by the demo version of Illusion 2.)



The way I usually make my emitters is to start with an existing emitter then modify it until it looks like something I want to save (and is often *very* different from what I started with). It's difficult to create a tutorial on that process though, since it involves a lot of experimentation. What I'll do here instead is try to take you through all of the steps I'd make to go from a boring "default" emitter (that would be created in a library if you select a library folder and click the "New Emitter" button) to a "cool" sparkle-type emitter. The "tricks" I do here may help you gain a better understanding of how to create your own Illusion emitters...


We'll start with the emitter on the left, and end up with the emitter on the right (or something pretty close to it I hope).

     

Click here for Quicktime movies of the emitters


First, some basics. When I experiment with emitters, I almost always do it with a stage emitter rather than a library emitter. I find it easier that way since there are less items in the hierarchy window, and if I want to save an intermediate version of the emitter I can use the "Add to Library" button. In this tutorial we need one of the "default" emitters, so we need to edit the library for a moment.

Either double-click on a library emitter, or r-click in the library window and select "properties". (If you're not sure what I mean by "library window", then maybe you should review the Illusion docs for a few minutes before continuing.) Select a folder in the hierarchy window of the properties dialog (not an emitter) and click the "New Emitter" button under the hierarchy window. Now close the props dialog by clicking OK. Now select this "New Emitter" in the library window and add it to the stage (just click on the stage -- make sure you're in "Add" mode and not in "Select" mode). Now double-click the stage emitter or r-click on it and select "properties" and we're ready to begin.

Well, maybe a quick review of terminology. Emitters are made up of one or more "particle types". Each particle type has various properties (size, life, velocity, etc.) that are also emitter properties. These emitter properties can be thought of as "scale factors" that are applied to the corresponding particle type props (I'm going to start abbreviating). When I refer to "size", I mean the particle type size property. When I want to refer to the emitter size property, I'll say "emitter size". (Note that particle types have many other properties such as color, "size over life", etc. Since there are no corresponding emitter properties to confuse us, when I say "size over life" you'll know that I'm always refering to a particle type.)

Ok, hopefully that didn't confuse you -- it was meant to help. Let's get started.

The first thing I want to change about the emitter is its visibility -- set the emitter visibility to 100% (it's at 50% to start with). I'll include the graph then the visual results after it from now on.

   

Now I want the particles to last longer, so increase life (I'm showing the previous setting with the reference graph):

   


See how the particles just "disappear"? That's ugly. We want them to fade out as they die, so we need to change their color gradient. (While we're at it we'll make them "intense" too, since sparkles are always "intense".) Make it look something like this:




What we now have is on the left, what we want is on the right.

   

We have more work to do, but not so much. We'll change the particle shape and colors first. Let's do colors since we just did that... make it look like this (sort of a rose color, then orange, then back to rose, then black):

   

Now to change the particle shape. (This is a good time to describe why some of you might not be seeing particles that look like the ones here. When you create a "default" emitter as we did at the start, the particle shape used is the first one in the current library. In most cases -- at least with the libraries that I create -- this first shape is called "basic blur". If you're using a different library, or have rearranged the particle shapes so that "basic blur" isn't first, your particles are going to look different that what you see here.) Click the "change shape" tab, and select one of the appropriate "sparkle" shapes that are already in the library. If there aren't any in the library, then you'll need to click one of these buttons:



and find an appropriate image (that you've made in a paint program for example). If you are using one of my libraries, chances are you will have a shape called "blurred star". That's the one we want to use, so select it, then click the "make active" button.

   


If you compare what we have now to what we want (above a little) you can see (I hope) that we don't have enough particles. We just need to increase the number property a little:

   

Wait, that looks like too many particles! Before we decide that let's add some variety. You can see how all of the particles are the same size, move at the same speed, and die at the same time. BORING! First we'll add some size variation:

   

Some velocity variation so some of the particles move a lot more:

   

Finally some motion randomness variation so some of the particles move in that crazy "random" way:

   

If you drag the emitter around, you'll see too much "scatter" -- the particles are not making a nice "trail". What we have, and what we want:

   

I want the particles to "scatter" after a little while, but not at first. Therefore I need to change the velocity over life graph to something like this:



The particle starts off moving very little, then moves a lot more near the end of its life. Motion randomness contributes to this "scatter" too, so we need to make it do the same type of thing -- little at first, much more later:



It's a subtle difference, but one that adds some "complexity" to the particle motion, especially if you watch this emitter for a long time.

I'm not sure that this is an exact duplicate of the emitter we're trying to create, but it's getting pretty close. Let's take a break and work on the other part of the emitter: the "glowing head".


Part 2: The "Glowing Head"







Alan Lorence    08 May 01