5D.Puddle

PURPOSE
Simulates circular water waves arising from the impact of rain droplets on a water surface. Each impact generates a wave that spreads out with time and fades away. A water surface is generated by adding up the contributions of all the waves that have not faded away completely.This surface is used to distort an input clip as if it were viewed through the water (i.e. the refraction due to the wavy water surface is simulated).

INPUT CLIPS
Clip to Rain on: the puddle surface.
Matte: the puddle waves will be scaled by the luminosity of this image, letting them be confined to non-black areas of this clip.

Tips:

This is a time based effect; what happens at frame 1 will evolve over time to create the effect, so jumping to a random frame will not necessarily show you the same result as when the sequence is generated sequentially.
Every time you switch on 'Restart Rain' all the currently active puddle drops will be killed and a new set created.
When a puddle drop is born, it has all the characteristics as set for that birth frame, for life.
If the Seed remains constant, the drops will be born in the same place each frame. Animate 'Seed' to give new birth positions for the droplets.
All the Rain parameters are used to define the characteristics of a set of drops at birth for the current frame. All newly created drops will have the new settings but all drops already active are unaffected, retaining their own birth characteristics. To see the result of the new settings you should 'Restart' and play the sequence again.
The other controls are global and will affect the result immediately, without the need to restart the sequence.
To start the sequence in the middle of a rainstorm, set 'Restart From' to a negative number of frames. The Rain parameters for the current frame will be used, and the positions of the drops calculated for the set number of frames.

SIMPLE PERSPECTIVE SEQUENCE

Output the puddle map.

Match perspective.

Fade out the distance.

Use with Glass to ripple the lake.

CREATION
Restart
Off=0:the rain strom continues......
On=1: the raindrop simulation will be restarted. Any raindrops currently alive are killed, and the simulation is run up from the frame specified by the Restart From control. Output frame generation then begins.
The timeline for this control has already been set up to restart at frame 0; then continue raining for the set of the time.

From: (Min: -1000.0 Max: 1000.0 Default: 0)
The frame to start the rainstorm from. This is similar to a 'pre-roll' and allows you to cut to the rainstorm in full downpour, rather than waiting for the effect to build up.

RAIN
Frequency (Min: 0.0 Max: 100.00 Default: 20.0)
Controls how many drops fall in the puddle on each frame. It is actually a scale of a default number of drops (hardwired at 10 drops per frame). The actual number of drops in any given frame varies randomly about this value by up to 10 drops. This seems to give fairly realistic looking drop arrival patterns.

Impact (Min: 0.0 Max: 10.0 Default: 1.0)
Controls the frequency (cycles per frame) of the wave generated when a drop hits the puddle. The name is a little strange, perhaps! Again, the value you enter is used to scale a default frequency, which we've found looks realistic for a typical puddle in the road looked at from average height. The hardwired frequency that is scaled is 10 cycles per frame.

Radius (Min: 0.0 Max: 1000.0 Default: 15.0)
This is the radius the wave from a drop will propagate out to before it dies away completely. By the time it reaches this size it won't be making any significant contribution to the water surface height. The time it takes to reach this radius is controlled by Rain endure. The value you specify here is randomly perturbed by up to a half of the value to add interest.

Endurance (Min: 0.0 Max: 1000.0 Default: 25.0)
The time it takes a wave from a drop to reach the specified Rain radius. It is measured in frames. This largely controls the speed at which things happen.

Wave Height (Min: 0.0 Max: 10.0 Default: 1.0)
Scales the amplitude of the water surface formed by adding up the contributions of all the waves from the raindrops.

SURFACE
Refractive Index (Min: -10.0 Max : 10.0 Default: 1.2)
Controls how much the 'water' bends light, and so how distorted the image seen through the water will get.

Chromatic Aberration (Min: 0.0 Max: 100.0 Default: 0.0)
Add color distortion if values are greater than 0.0.
Note: if you are not using chromatic aberration effects make sure the value is set to 0.0 to it turn off and speed up the processing.

LIGHT
XYZ position (Default: image center)
The light source position.

Glossiness (Min: 1.0 Max: 1000.0 Default: 45.0)
Controls the tightness of the specular lighting highlights.

Contrast (Min: 0.0 Max: 100.0 Default: 100.0)
Controls the relative brightness of the specular highlights and the input image refracted through the wave surface. At 100.0, the image is at full brightness.

Brightness (Min: 0.0 Max: 200.00 Default: 0.0)
How bright the light is. Values over 100.0 will start to burn out.
Note: if you are not using lighting effects, make sure the value is set to 0.0 to turn off the light and speed up the processing a little.

Red/Green/Blue (Default: white)
The color of light.

OutMap (Default: Off)
Off=0: the raindrop simulation is run and at every frame a water surface is generated. This is then used to refract light from the input image to give an output image.
On=1: the water surface height is encoded as a grey level image and this is written into the output clip. Refraction is not done. This clip can be fed into Glass to complete the effect, or it may be used for other purposes. However, if you use this facility with Glass, you will probably need to turn up the smoothing, because the height images only have 256 levels. When everything is done internal to Puddle, much greater accuracy can be preserved.

Reverse Matte (Default: Off)
Off=0: the matte clip is used as is is, if Use Matte is on.
On=1: reverses the effect of the matte if 'Use matte' is on.

Use Matte (Default: Off)
Off=0: the matte clip is not used.
On=1:the second clip is used to scale the amplitude of the wave. The luminance is used. The waves can be limited to selected areas using a suitable matte.

Fill Mode (Default: Edge Duplication)
Controls how parts of the output image that should be filled by areas of the input image that are beyond the actual input image's edges, are filled.
Edge Duplication=0: the nearest edge of the input image is used.
Black=1: the output image areas are filled with black.
Wrap=2: the input image is treated, as it were an infinitely repeating tiling of the actual input image.

Seed (Min: 0.0 Max: 9999.0 Default: 119)
Seed for the random number generator used by the rain drop simulator. The time line is already set to give a new random number each frame so the rainstorm patterns do not repeat each frame. See Tips above.