In this tutorial, we'll start working with the gradient controls to affect the coloring of your AfterBurn effect.
- In 3ds Max, select File->Open, and from your /Scenes/AfterBurn/Tutorials folder, select the file AB-Tut2.max.
This tutorial picks up where Tutorial 1 ended, with a Super Spray emitter, moving left to right across the top of a flat Box primitive.
- Select Rendering->Environment, and click on the AfterBurn entry in Atmosphere->Effects to open the AfterBurn atmospheric.
- Go to the Colors rollout and left-click on the Color1 Gradient field (the white box) to bring up the Gradient Editor. This floating window is fully resizable.
- Right-click on the rightmost color key, and from the dropdown menu, select Key Color.
- Change this key color to Black (RGB: 0, 0, 0). Do not close the Gradient Editor yet.
- Now, activate the Camera01 view and render frame 100.
Notice how the smoke gradually changes from white to black. Those particles that are just born are white, and as they get older, they turn black. This follows the gradient settings you just made. You can add as many Color keys to the Gradient as you want to achieve the result you want.
- Return to the Gradient Editor, and in the middle of the color gradient, left-click to create another Color key. The position of the key is not critical.
- Change this new color key to Red (RGB: 255, 0, 0), then close the Color Selector and Gradient Editor.
Next, you'll add another color gradient and blend between them.
- In the AfterBurn atmospheric dialog, go to the Colors rollout and activate the Color 2 radio button.
Now you have two separate color gradients affecting the AfterBurn effect. The first is the white/red/black one, and the second is this new, all-white one.
- Activate the Camera01 viewport and render frame 100.
You should see that the Color 1 gradient is visible at the center of the effect while the new Color 2 gradient is visible at the edges of the volumetric effect. This is due to the fact that the c1->c2->c3 option is set to Distance. This option changes the color of the volumetric puff from Color 1 to Color 2 based on the distance from the particle center.
However, you can affect where the cross-over occurs between the two color gradients by using the Pos. spinners. The Pos. (Position) spinners adjust the distance where Color1 starts to face into Color2. And by using the AFC (Animation Flow Curve), you can also vary this blending over the particle age.
- Right-click over the Color1 Pos. AFC button and select Enable. The AFC default transition function is linear, which is good enough for this tutorial.
- Leave the left Pos. spinner at 0.0 and set the right Pos. spinner to 0.3.
These numbers indicate the relative distance from the particle center. 0.0 is the particle center and 1.0 is the particle surface. By the end of the particles' lives, the Color 1 positioning is 0.3 (roughly one-third) away from the particle centers before the transition to Color 2 begins.
- Activate your Camera01 viewport and render frame 100 again.
Note that the red color is much closer now to the surface towards the end of the smoke trail than it was before.
- Go to the Noise Animation rollout and change the Noise Type from Turbulence to Fractal.
- Now, render frame 100 again.
The Fractal noise seems to be more voluminous than the Turbulence noise setting.
As you can see, the color gradients that AfterBurn uses can be a powerful tool in creating it's effects, especially when you start blending multiple gradients together to get complex looks out of the volumetric puffs. In the next tutorial, you'll discover other ways of coloring your AfterBurn volumetric effects. Specifically, you'll get to work with the new AfterBurn Explode Daemon to see how to create a convincing explosion.