Autodesk 62205-051408-9001 User Guide - Page 360

14 Creating Particle Effects There are three ways to pick a color. You can doubleclick a tag (or where there is no tag) to show the Pick Color dialog. You can double-click a tag to pick directly from a color palette (by double-clicking a color or clicking one and pressing ENTER). You can also click a tag and then CTRL-click the tag to access the color palette. Pick from color palette Click here to toggle color model Note: You can see Life Color changes in the preview more clearly if Intense is disabled. You can also SHIFT-clickseveral tags to move them simultaneously. When a few tags are selected, you can ALT-drag one (usually an end tag) to expand them proportionally. When there is only one color tag, the color fills the entire gradient and the particle is that color its entire life. Random-If Random is enabled, a particle's color does not cycle through the gradient. Instead, each particle remains the same color (a color picked randomly from the gradient) its entire life. Each particle is a different color, though. (The Autumn Leaves library emitter uses random color, for example.) You can add variation to the color in the effect by enabling Random. Repeat-When Random is disabled, you can adjust the Repeat field between 0 and 10. When Repeat is set to 0, a particle cycles through the Life Color gradient exactly once during its lifetime. The Repeat field is used to repeat the color gradient a number of times over the life of the particle. Note: If you want the colors to repeat smoothly, make sure that the color tag at the right end of the gradient is the same as the color tag at the left end of the gradient. One use for the Repeat field is to make particles sparkle. With the Intense option enabled, and Repeat set to 5, the particles in the preview sparkle. If too many of the particles seem to blink on and off at the same time, increase the Life Variation property for the particle type. Another example is a strobing effect. Set color from white to black to white, then increase the Repeat field. When particles have Intense enabled, their color also affects their visibility. Since intense particles are additive, a black particle is invisible, regardless of the opacity settings. Life Opacity The Life Opacity gradient represents the opacity (or visibility) of a particle over its life. For example, you can use this gradient to make particles fade out as they die. This gradient works the same way as the Life Color gradient, but the opacity tags are only grayscale colors. Black represents complete transparency and white represents complete opacity. Note: There must be at least one opacity tag. If you delete the last tag, it is added back at the middle of the gradient. Link-When Link is enabled, you cannot add or modify opacity tags. In this case, the opacity is linked to the Life Color gradient, so the Life Opacity gradient becomes a grayscale version of the Life Color gradient. Dark particles are more transparent and brighter particles more visible. Thus, you should disable Link if you want to make dark particles that are visible (black smoke, for example). You can enable Link for many other types of particle. 344