Animate the flow of gaps, twist, and/or textures

If tubes have gaps, twist, and/or textures applied to them, you can animate the pattern they create “flowing” or cycling along the length of the tubes as if the tubes were joined at the ends.

By animating the flow of gaps, you can create effects such as rainfall. By animating the flow of twist, you can get a spiraling effect. The following images show a texture flowing one complete cycle from root to tip.

To make gaps, twist, and textures flow

1. Select the stroke.
2. In the Attribute Editor, click the brush tab.
3. Set the desired gap, twist, and/or texture settings. For details, see Create gaps in tubes, Set twist attributes, and Map textures to color and opacity, respectively.
4. Expand Flow Animation and set a Flow Speed for the gaps, twist, or texture. Positive numbers make them flow from tube base to tip. Negative numbers make them flow from tip to base.

   The Time Clip and Stroke Time options also animate tube growth when turned on. For information, see Animate uniform tube growth, Animate the growth simulation, and Animate tube death.

   You can use the Time setting to animate flow over time. For more information, see Time.

5. If you are animating gap flow, you can check that the flow is as you want it before rendering the animation by clicking the Play Forward button in the scene view.
   TipYou can loop the brush animation smoothly. For details, see Loop brush animations.
6. Render the animation. See Render a scene with Paint Effects strokes.

Animate uniform tube growth

You can animate the tubes along the stroke path growing at the same time, as if they were all “planted” simultaneously. Any gaps, twist, and/or texture applied to the tubes will flow along the length of the tubes as the tubes grow.

To animate all the tubes along the stroke growing at the same time

1. Select the stroke.
2. In the Attribute Editor, click the brush tab.
3. Expand Flow Animation and set a Flow Speed. (If you have gaps, twist, or textures applied to the tubes, the flow speed also defines the speed that they flow along the tube.)
4. Turn on Time Clip.
5. Set the Start Time (seconds),the time in the animation that the tubes will first appear) and the End Time (seconds), the time in the animation when tubes first begin to die).

   Set the End Time (seconds) to end at the same frame your animation ends or later. This ensures that the tubes do not die before the animation is complete. For details on making tubes die, see Animate tube death.

   You can use the Time setting to animate growth over time. For more information, see Time.

   NoteStart Time (seconds) and End Time (seconds) are measured in seconds. So if your Time unit is set to 24 fps, for example ( Window > Settings/Preferences > Preferences, then click the Settings category), and the Start Time (seconds) is 1, then tubes will first appear on frame 24.

   If you know what frame you want tubes to appear on, divide this frame number by the frames per second defined by your Time unit to determine what value to enter in the Start Time (seconds) box. For example, if you want your tubes to appear on frame 60 and your Time unit is set to NTSC (30 fps), divide 60 frames by 30 frames per second, for a Start Time (seconds) of 2 seconds.

   You can perform this calculation by creating an expression in the field. Type an equals sign (=) followed by the calculation. In the previous example, you would type:

   =60.0/30

   Notice that the time must have a floating point decimal.

6. In the scene view, click the Play Forward button to check that the growth is as you want it.
   TipYou can loop the brush animation smoothly. For details, see Loop brush animations.
7. Render the animation. See Render a scene with Paint Effects strokes.
   NoteIf you are simultaneously animating tube growth and texture flow (for example, the growth of a textured tree), the texture may appear to flow faster than the tree grows. To remedy this, select the strokes and run the script freezeBrushTexture.mel on the command line (stored in your mayapath/Maya/Contents/scripts/paintEffects (Mac OS X) or mayapath/scripts/paintEffects (Windows and Linux) directory).

Animate the growth simulation

You can animate the growth simulation. Tubes “planted” at the beginning of the stroke start growing at the beginning of the stroke path and continue to grow as new tubes start growing in steps along the path. Any gaps, twist, or texture applied to the tubes will flow along the length of the tubes as the tubes grow.

To animate all the growth simulation

1. Select the stroke.
2. In the Attribute Editor, click the brush tab.
3. Expand Flow Animation and set a Flow Speed. (If you have gaps, twist, or textures applied to the tubes, the flow speed also defines the speed that they flow along the tube.
4. Turn on Time Clip.
5. Turn on Stroke Time.
6. Set the Start Time (seconds), the time in the animation that the tubes will first appear) and the End Time (seconds), the time in the animation when tubes first begin to die).

   Set the End Time (seconds) to end at the same frame your animation ends or later. This ensures that the tubes do not die before the animation is complete. For details on making tubes die, see Animate tube death.

   You can use the Time setting to animate growth over time. For more information, see Time.

   NoteStart Time (seconds) and End Time (seconds) are measured in seconds. So if your Time unit is set to 24 fps, for example ( Window > Settings/Preferences > Preferences, then click the Settings category), and the Start Time (seconds) is 1, then tubes will first appear on frame 24.

   If you know what frame you want tubes to appear on, divide this frame number by the frames per second defined by your Time unit to determine what value to enter in the Start Time (seconds) box. For example, if you want your tubes to appear on frame 60 and your Time unit is set to NTSC (30 fps), divide 60 frames by 30 frames per second, for a Start Time (seconds) of 2 seconds.

   You can perform this calculation by creating an expression in the field. Type an equals sign (=) followed by the calculation. In the previous example, you would type:

   =60.0/30

   Notice that the time must have a floating point decimal.

7. In the scene view, click the Play Forward button to check that the growth is as you want it.
   TipYou can loop the brush animation smoothly. For details, see Loop brush animations.
8. Render the animation. See Render a scene with Paint Effects strokes.
   NoteIf you are simultaneously animating tube growth and texture flow (for example, the growth of a textured tree), the texture may appear to flow faster than the tree grows. To remedy this, select the strokes and run the script freezeBrushTexture.mel (stored in your Maya scripts directory) on the command line.

Animate tube death

You can animate special effects, like tubes “bursting” from the stroke path, by setting birth and death times that define when tubes start growing in the animation, and when they begin to disappear.

When the animation reaches the death time, segment at the tube roots disappear (or die) while segments continue to be added at the tube tips. When the tube reaches its life span, the segments continue to disappear from the root to the tip until the tube completely disappears.

Any gaps, twist, or texture applied to the tubes will flow along the length of the tubes as the tubes grow.

To animate tube death

1. Select the stroke.
2. In the Attribute Editor, click the brush tab.
3. Expand Flow Animation and set a Flow Speed. (If you have gaps, twist, or textures applied to the tubes, the flow speed also defines the speed that they flow along the tube.
4. Turn on Time Clip.
5. Turn on Stroke Time.
6. Set the Start Time (seconds), the time in the animation that the tubes will first appear) and the End Time (seconds), the time in the animation when tubes first begin to die).

   You can use the Time setting to animate tube death over time. For more information, see Time.

   NoteStart Time (seconds) and End Time (seconds) are measured in seconds. So if your Time unit is set to 24 fps, for example ( Window > Settings/Preferences > Preferences, then click the Settings category), and the End Time (seconds) is 4, then tubes start to die on frame 96.

   If you know what frame you want tubes to begin to die on, divide this frame number by the frames per second defined by your Time unit to determine what value to enter in the End Time (seconds) box. For example, if you want your tubes to begin to die on frame 120 and your Time unit is set to NTSC (30 fps), divide 120 frames by 30 frames per second, for an End Time (seconds) of 4 seconds.

   You can perform this calculation by creating an expression in the field. Type an equals sign (=) followed by the calculation. In the previous example, you would type:

   =120.0/30

   Notice that the time must have a floating point decimal.

7. In the scene view, click the Play Forward button to check that the animation is as you want it.
   TipYou can loop the brush animation smoothly. For details, see Loop brush animations.
8. Render the animation. See Render a scene with Paint Effects strokes.