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Chapter 8 Working With Particles 607
Additional Cell Parameters Based on the Selected Color Mode
Each of the options in the Color Mode pop-up menu displays a different set of
parameters.
Color: A color well available when the Color Mode is set to Colorize. Use it to specify a
color to use to tint the particles. You can also modify each particle’s alpha channel,
altering its opacity. This parameter is unique to the cell object. You can either click the
color well to choose a color, or open the disclosure triangle and use the Red, Green,
Blue, and Alpha channel sliders.
Opacity Over Life: A gradient control that appears when Color Mode is set either to
Original or Colorize. Use it to change the opacity of particles based on their age. This
gradient control is limited to grayscale values, which are used to represent varying
levels of transparency. White represents solid particles, progressively darker levels of
gray represent decreasing opacity, and black represents complete transparency. A
simple white to black gradient represents a particle that is solid when first generated,
but which fades out gradually over its lifetime until finally vanishing at the end. The
Opacity Over Life parameter has four controls:
• Gradient Preset pop-up menu: Gradients from the Library (default or custom)
appear in this pop-up menu. Choose a gradient from this menu to load it into the
Gradient Editor. None of the default gradients have opacity gradients.
• Opacity bar: To add a new opacity tag to the gradient, click anywhere within the
opacity bar. Click an opacity tag to select it, and then change its value with the
Opacity slider. To change the distribution of opacity, drag an opacity tag along the
opacity bar, or select an opacity tag and use the Location slider. Change the spread
of color between two gradient tags using the spread controls (triangles). To delete a
gradient tag, drag it away from the gradient bar until it disappears.
• Opacity slider: Changes the shade of a selected gradient tag, from 100 (opaque/
white) to 0 (transparent/black).
• Location slider: Changes the location of the selected gradient tag relative to the
gradient bar.
Color Over Life: A gradient control that appears when the Color Mode is set to Over
Life. Use it to change the color of generated particles based on their age. When born,
particles are tinted with the leftmost color in the gradient. Over their lives, their color
changes through the range of the gradient, from left to right, until finally reaching the
rightmost color at the end of their lives. Similar to the Opacity Over Life parameter, the
Color Over Life parameter has five controls:
• Gradient Preset pop-up menu: Gradients from the Library (default or custom)
appear in this pop-up menu. Choose a gradient from this menu to load it into the
Gradient control.
• Opacity Gradient control: A gradient control that allows you to change the opacity
of generated particles based on their age. All color tags are limited to shades of gray.
01112.book Page 607 Sunday, March 13, 2005 10:36 PM