5D.Bubbles

PURPOSE
Simulates several different kinds of bubbles, modelling their motion, and rendering them with optional reflection maps and other effects. The bubbles are meant to resemble those found in liquids (e.g. fairly small, numerous, with various types of growth and motion), rather than one (or a few) very large bubble(s). These other types of bubbles might require different modelling and rendering techniques (e.g. vibrating surfaces, thin film interference).

INPUT CLIPS

Birth Clip: bubbles will only be created within non-black areas of this image.
Burst/Gather: bubbles may burst/gather if they encounter non-black areas of this image. They may burst if Do Burst is on and the Burst Probability is greater than 0.0; otherwise they will gather, slow down, depending on Friction. A value greater than 0.8 for friction is suggested. If Gathering is used then Friction only takes effect when a bubble enters the non-black region of the clip.
Reflection: images from this clip can be seen reflected in the bubbles. Softening, by defocusing or blurring, the reflection clip can enhance the rendering of the reflections.
Background Clip: clip over which the bubbles will be composited.

Tips:

Bursting Bubbles:
The second input clip for bubbles will cause the bubbles to burst (if the intensity level is 128 or greater) and burst is turned on. NOTE: Bubbles may unexpectedly burst if they reach the end of their life.

Gathering Bubbles:
The second input clip also controls gathering; the bubbles will rapidly slow down and gather within regions of this clip (intensity level of 128 plus). If the burst probability is high they will burst before they can gather. You should set Slow Up to something around 80.0 to stop them rapidly.

Reflections on Bubbles:
If the reflection map makes the bubbles look a little ragged then pre-process the reflection map clip with a defocusing effect to soften the image.

TIME EDITOR CONTROLS

CREATION
Preroll Frames (Min: 1 Max: 1000 Default: 150)
Number of frames to perform as a pre-roll before the first output frame is rendered and preroll is requested from the PI.

Number (Min: 0.0 Max: 10000.0 Default: 20.0)
How many new bubbles will be created on each frame.

To Live (Min: 1.0 Max: 1000.0 Default: 200.0)
Specifies the time in frames for which a bubble will live. After this, the bubble will either burst or vanish.

POSITION
Radius (Min: 0.0 Max: 100.0 Default: 10.0)
The width of a region about the bubble generation line within which bubbles will be created (if the bubble birth creation feature is being used, bubbles will be created in the overlap of this region and non-black areas of the matte image).

XY Left (Default: left)
XY Right (Default: right)
Co-ordinates of the ends of the bubble generation line.

SIZE
Radius (Min: 1.0 Max: 10.0 Default: 4.0)
Size which the bubbles are created at, or can grow to.

Radius Variance (Min: 0.0 Max: 1.0 Default: 1.0)
Variation in the initial size of the bubbles.

To Maximum (Min: 1 Max: 500 Default: 25)
Time in frames between the birth of a bubble and when it reaches its maximum size (for expanding bubbles).

CLIP2 DEATH

BURST
Probability (Min: 0.0 Max: 100.0 Default: 50.0)
Probability of a bubble bursting on a single frame in which it is over a non-black burst matte area.

Quantity (Min: 0.0 Max: 100.0 Default: 100.0)
How much of a 'sparkling effect' is rendered on a bubble bursting.

Radius (Min: 0.0 Max: 100.0 Default: 10.0)
The radius out to which the 'sparkling effect' of a bursting bubble will persist.

After Life (Min: 0.0 Max: 100.0 Default: 6.0)
Specifies how long the burst bits of a bubble will persist for after a bubble has burst.

GATHER
Slow Up (Min: 0.0 Max: 100.0 Default: 80.0)
When a bubble hits a gather region (non black area of clip 2) it will be slowed down by this amount and thus appear to gather in the desired region.

FORCES

SWIRL
Density (Min: 0.0 Max: 100.0 Default: 60.0)
How many bumps in the fluid a bubble will run in to, across the width of a frame.

Amplitude (Min: 0.0 Max: 100.0 Default: 1.0)
How much the path of the bubble will be changed by running in to a bump in the fluid.

To Maximum (Min: 0.0 Max: 100.0 Default: 0.0)
Time in frames after a bubbles birth, over which the bumpiness will build up in strength.

GRAVITY
Angle (Min: -360.0 Max: 360.0 Default: 270.0)
Direction in which gravitational acceleration acts, measured in degrees, anti-clockwise from zero at due East.

Strength (Min: 0.0 Max: 1000.0 Default: 20.0)
Specifies an acceleration experienced by the bubbles. The direction of the acceleration can be controlled by the Gravity Angle.

VELOCITY
Initial (Min: -20.0 Max: 20.0 Default: 3.0)
Speed at which the bubbles begin moving when they are created.

Direction (Min: 0.0 Max: 360.0 Default: 90.0)
The direction (in degrees, measured from zero at due East) in which the bubbles will begin to move when they are born.

Variance (Min: 0.0 Max: 200.0 Default: 0.0)
Variability in the velocity a bubble starts off with.

Friction (Min: 0.0 Max: 100.0 Default: 0.0)
How much of the initial velocity of a bubble is lost in each frame. If there are no other influences, bubbles would eventually slow to a halt if friction was greater than zero. Usually however, gravity, swirl and other factors play an important part too.

LIGHT

Target XY (Default: center right)
Source XY (Default: center left)
Position of where the light is coming from (source), and pointing to.

Source Z Position (Min: -100.0 Max: 100.0 Default: 100.0)
Relative position (in front/behind the image plane) of the light source.

Spread (Min: 0.0 Max: 180.0 Default: 90.0)
Specifies the angle (in degrees) of a cone of illumination (centred on the illumination direction) within which the light shines.

Brightness (Min: 0.0 Max: 500.0 Default: 100.)
Intensity of the light illuminating the bubble surface (added to the Ambient colour of the bubble surface, so the degree of 'shading' depends on the relationship between these two controls.

(Min: 0.0 Max: 1000.0 Default: 30.0)
How concentrated the light will be about the direction of illumination.

RGB (Default: grey)
The colour of light.

SURFACE

COLOUR
RGB (Default: nearly black)
The colour of the bubble. Being black, or colourless means the bubble takes it's colouring mainly from the light and refelections supplied.

Colour Variance (Min: 0.0 Max: 100.0 Default: 0.0)
Variation in the surface colour of bubbles. If this is zero, all bubbles will have the same surface colour (specified by the bubble colour).

Monochrome Variance (Min: 0.0 Max: 00.0 Default: 0.0)
Variation in the brightness of the bubble surfaces. If this is zero, all bubbles will equally bright.

CLIP3 REFLECTIONS
Intensity (Min: 0.0 Max: 200.0 Default: 50.0)
Scales the contribution to the bubble surface brightness made by the reflection map image (if reflections is on).

Ambient (Min: 0.0 Max: 100.0 Default: 60.0)
Brightness of the darkest portion of a rendered bubble.

Shine (Min: 1.0 Max: 200.0 Default: 45.0)
Controls how dense a bubble gets in areas where it will be bright due to the light. This is used to get a reasonable appearance for rendered bubbles composited over the background and each other.

Highlight (Min: 1.0 Max: 200.0 Default: 10.0)
How tight the highlight due to the light shining on the bubble surface is to be.

PI CONTROLS

restart
Restart the bubble simulation, destroying all current bubbles first.

preroll
Run the particle system for the specified number of pre-roll frames before generating the first frame of the output clip.

RENDER PREROLL
This MUST be turned ON prior to rendering a sequence if you need the preroll effect. Rendering starts a completely new bubble system; it cannot continue from where you currently are.

SIZE STYLES
assorted: randomly selected birth sizes.
shrinking: the bubbles will shrink with time.
variable growth: bubbles expand overtime, and the smaller bubbles will start to move more quickly.
linear Growth: the bubbles expand over time moving at the given rate.

CLIP CONTROL
birth limits (Default: Off)
On: use your birth matte. Make sure that the birth and position radius 'cover' the areas of matte you want to use. Bubbles will only be born within the white area of your matte.

gather (Default: Off)
On: use the burst/gather clip. See Tips above

burst (Default: Off)
On: use the Gather/Burst clip. When bubbles encounter non-black areas of the clip, they burst (with an appropriate rendering of this), if the Burst Probability is greater than zero. This clip can also be used to specify a region in which the bubbles will gather.

reflections (Default: On)
On: the reflection clip is used to enhance the bubble surface.

RENDERING
colour&density: the colour (brightness) of a bubble and its density (opacity) evolve.
colour: the colour (brightness) of a bubble changes, while its density stays constant.
Density: the colour (brightness) of a bubble stays constant, while its density (opacity) changes.
This effects how the bubbles composite with one another and with the background image and can have a very great effect on the final appearance.

DEMOS
basic: Set up all controls for a 'basic' bubble effect.
soap: Sets all parameters for a 'soap bubble' effect. The result is better seen than described here!
water: Small bubbles move more slowly than larger bubbles and all bubbles grow over time.
champagne: Set all parameters for Champagne like bubbles. Again, it's probably better seen than described!

5D.Bubbles

Index