I assume you know the basics of C2.
You can download a sample capx and skip this tutorial as you may want to explore it yourself.
Let's Get Started !
1. Create a new project.
2. Name it as you want.
3. Change Layout color to pure black.
4. Place a particle object on top of layout.
5. Make a dot with soft edges. For this purpose make sure the hardness is not much high. I recommend 5-15.
Configure Particle Effect
Apply the following values. I'll explain each. I only mention those who are changed.
Angle : 90
Turns the particle emitter down. Since the emitter is placed on top of layout this will push particles downwards.
Blend Mode : Additive
Additive means when two particles overlap each other the color of both will be more intense. The grayish particles will turn to white at intersection point.
Rate : 100
My aim for this tutorial was to fill the entire screen with dust particles. So I set to a high value. If you have a small place then you may want to use a lower value for this.
Speed : 40
Dust is moving slow. But not too slow.
Size : 0.1
This is set to almost zero because it will be used with size randomiser. So there is a wide range from small to big dust particles.
Opacity : 40
Unfortunately there is no option to set a range for this value. So that some dusts would be more opaque than others.
X-Randomiser : Window width
This defines the area in which we want the dust to appear randomly. Think of it as a box.
I used the windows X-width for the x-Randomiser
Size Randomiser : 150
This will give the particles the effect as if the bigger ones are closer to the camera and the smaller ones are farer away. It gives a touch of depth to the particles.
Acceleration : 0
The dust should move with a constant speed. So acceleration is shut off here by setting it to 0
Gravity : 10
Ensures that particles move slowly downwards.
Opacity Randomiser : 1
It will give the dust a flickering effect. Higher value mean more flickering.
Timeout : 10
Depending on other properties like width, speed this can change.
What you should always keep in mind is to give the particle enough time to be on scene and that it doesn't suddenly disappear.
When you have done everything you should have something like this
[Advanced] This is nice but not awesome. I want awesome!
Sure. We going to improve the effect. Create another particle effect. Copy the property values from the first one.
Draw a dot
This time we going to make the dot more thick. So give at a hardness of minimum 20. I recommend 25 though. Draw the dot and close the image editor.
This one should be more opaque
Rate : 80
Also this one should have little bit less rate than the first one we created
That's all the changes you have to do for the second particle effect.
If you did everything correctly you will end up with this
Well, we are going to add a small but noticeable detail. Again, create another particle effect. The dot can be same as the second particle effect we created. This time place it on bottom of layout. Turn it upwards.
Rate : 1
Only 1 particle per second.
Opacity : 4
Yes. This should be almost invisible.
Speed : 25
Timeout : 30
Because it moves so slow we increase the timeout.
Acceleration : 0
Size randomiser : 150
Just like the other two particle effects.
Finished. Now for real
Congrats. You made it! You should have this at the end.
Notice how some particles move upwards in the background.
My first tutorial. I'm not sure if it was written well. I hope you enjoyed it anyways. I can continue with more "how to make ..." particle effects tutorials if there is enough interest.