2010

Table Of Contents
8 Modify the Opacity so that areas in the container that are very dense
appear less opaque, areas that have very little Density become totally
transparent, and the transition between areas that are totally transparent
and areas that are more opaque is less gradual.
In the Attribute Editor, go to the Shading section. Look at the Opacity
graph in the Opacity subsection. This graph represents the relationship
between Opacity values and Density values (the Opacity Input).
Opacity values range from 0 on the bottom (totally transparent, no
opacity) to 1 on the top (totally opaque).
Density values range from 0 on the left side (no Density) to 1 on the right
side (high Density).
So for the linear graph shown above, where Density values are 0, Opacity
values are 0, making the Density totally transparent, where Density values
are 0.5, Opacity values are 0.5, making the Density partially opaque, and
where Density values are 1, Opacity values are 1, making the Density
totally opaque.
Click the first dot on the Opacity graph to select the position marker.
Position markers mark the location on the graph from left to right (the
Opacity Input value). The outline of the dot is white when a position is
selected.
806 | Chapter 16 Fluid Effects