Ripple

Category: Texture Generators

Shader Family: Texture

Output: Scalar

Simulates ripples on the surface of a fluid based on a coordinate input. 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-0 and its amplitude is the same as the value of the envelope at that point. The wave travels inside 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.

Name	The shader's name. Enter any name you like, or leave the default.
Coordinates	Defines the U, V, and Z coordinates of the texture.
Time	Controls the current time of the ripple. At 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 wave within the envelope. A high value results in many waves; a low value has the opposite effect.
Amplitude	Defines the amplitude of the ripple's envelope at 0 time.
Spread Rate	Controls how quickly a wave spreads from one boundary to another.
Decay	Controls the decay of the ripple amplitude in relation to time. A high value increases the liquid's viscosity (e.g., syrup) and causes the waves to decay quickly. A low value prolongs the waves' decay and simulate a less viscous liquid (e.g., water). For no decay, leave this parameter at 0.
Group Velocity	Defines the speed of the center of the envelope. In a physical situation, this value is always lower than the Phase Velocity.
Phase Velocity	Controls the speed of the wave that "lives" under the envelope. In a physical situation, this value is always greater than Group Velocity.
Spread Start	Defines the spread of the envelope at the moment the wave is formed (after 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.

Render Tree Usage

Use this shader to drive a parameter with a texture effect anywhere in a render tree. This shader generates a texture that can be used as a color, a Weight value in a mixer shader, or to drive any Surface shader parameter.

Connect a Texture Space Controller shader to drive the Coordinate value of this shader.