Ripple

| Texture | Ripple | Advanced | Render Tree Usage

Category: Texture

Shader Family: Texture

Output: Color

Simulates ripples on the surface of a fluid. To understand how the parameters work, keep in mind that a ripple is composed of two waves: the envelope and the wavelet. The envelope is a hump shape under which the wave "lives." The wave exists only where the envelope is non-zero and its amplitude is the same as the value of the envelope at that point. The wave travels within the envelope. Thus, the overall effect is of waves being created at the inner envelope boundary, growing in amplitude as they travel outward to the envelope center and finally decaying as they approach the outer boundary.

The default parameters correspond to typical water, where the unit square is one square meter.

In order to quickly see your effect, try boosting the Amplitude parameter from the Ripple tab.

Name	The shader's name. Enter any name you like, or leave the default.

Texture

Texture Space

Selects the texture projection to use. See Specifying a Texture Projection [Texturing].

Bump Mapping

Enable	Switches bump mapping on or off.
Bump Map Factor	Defines how "bumpy" the bump map will be. A negative value inverts the bump inward; a positive bump map factor bumps outward.
Use Alpha	Uses the texture's alpha channel to achieve a bump map.

Ripple

All the parameters on this property page can be driven by other shaders using the connection icon.

Colors

Color 1	Defines the first color of the ripple pattern.
Color 2	Defines the second color of the ripple pattern.

Alpha

Copy Alpha to RGB	Multiplies the RGB channels with the alpha channel by the factor defined in the Alpha Strength parameter.
Alpha Strength	Determines the factor by which the alpha is multiplied with the RGB channels.
Time	Controls the current time of the ripple. At 0.0, the ripple has not formed yet. At 0.1, however, the ripple begins forming while taking into consideration the Amplitude and the Spread Start.
Frequency	Defines the frequency of the waves within the envelope. The higher the value, the more waves.
Amplitude	Defines the amplitude of the ripple's envelope at 0.0 time.
Spread Rate	Controls how much the spread increases in relation to time. In a physical situation, the envelope widens and moves outward as time passes. A value of 0.5 ensures that the inner boundary of the envelope always stays at the ripple origin.
Decay	Controls the decay of the ripple amplitude in relation to time. A high value increases the liquid's viscosity (e.g., syrup-like) and causes the waves to decay quickly; a low value prolongs the waves' decay and simulates a less viscous liquid (e.g., water). For no decay, leave this parameter at 0.0.
Speed	Defines the speed of the center of the envelope. In a physical situation, this value is always smaller than the Phase Speed.
Phase Speed	Controls the speed of the wave that "lives" under the envelope. In a physical situation, this value is always greater than Speed. This parameter is called Phase Velocity in 2D-Ripple.
Spread Start	Defines the spread of the envelope at the moment the wave is formed (after 0.0). The spread is the distance between the two boundaries of the envelope.
Origin	Defines the X, Y, and Z point of origin of the ripple.

Advanced

Bump Mapping

Step	Controls the U, V, and Z steps of a bump map. Use this parameter to "smooth" bumps or make them more jagged.

Alternate

U, V, Z

Specifies whether every other copy of the repetition should be reversed so that the successive copies of the texture are alternated.

Repeats

Texture Repeats

Contains the repetition factor in X,Y, and Z. A value of 2, for example, shrinks the texture so that it fits twice in a [0..1] interval.

UV Remap

Minimum, Maximum

Determines the remapping of the texture image. For a 2D image, only X and Y are used.

Render Tree Usage

Color parameters can be connected to other textures or image processing shaders. A texture's scalar parameters can be altered to create interesting effects by applying Texture Generator shaders to them. For example, the Bump factor can be controlled with the Turbulence or even Ripple Texture Generator shader.

A texture shader has limitless capabilities in a render tree. It can texture an object, be used as a camera or light projection, define bump or displacement maps, or be blended with any number of other textures to create any effect.