ANR Ripple Tank

Overview

Ripple Tank makes ripples on a water surface the size of the frame. A drop lands at Emitter X and Emitter Y on the Start Frame, and a second drop can follow Second Delay seconds later. Their rings spread out, bounce off the edges of the frame, cross each other and calm down over time.

With Distort Source at 0 the node outputs the height of the water as a grey image: mid-grey is calm water, brighter is higher. Raise Distort Source to see Source through the moving water instead.

Use it for drops landing on a logo or title, puddles and water surfaces, liquid transitions, and as a height map for other nodes.

Inputs

1. Sourceoptional

   The image seen through the water when Distort Source is above 0. The height output does not use it.

2. Maskoptional

   Limits the effect: where its alpha is black, Source passes through unchanged.

Output. With Distort Source at 0, an opaque grey height image covering the project format, mid-grey for flat water. Above 0, Source distorted by the ripples.

Quick start

1. Add ANR Ripple Tank and connect the image to Source.
2. Set Frames per Second to your project's frame rate, and Start Frame to the frame where the first drop lands.
3. Place the first drop with Emitter X and Emitter Y, as fractions of the frame (0.5 is the middle). Place the second with Second X and Second Y, or set Second Strength to 0 for a single drop.
4. Play the shot and watch the height image. Set Wave Speed for how fast the rings spread and Damping for how quickly they calm down.
5. Set Amplitude for the height of the waves and Detail for how fine they can be.
6. Raise Distort Source to see Source through the water.

The panel

The node's panel as Nuke shows it, with the values of a new node. Click any control to see what it does; tabs and sections work as in Nuke.

All controls

Tips

• For stronger distortion and lit, glinting water, connect the height image to the Height input of ANR Relief Surface and raise its Relief: it can exaggerate faint waves much further than Distort Source can.
• Pulse Radius sets the size of the drop: small drops make sharper rings, large ones broad swells.
• Set Damping to 0 for ripples that keep bouncing round the frame.
• Wave Speed is in pixels per second, so larger formats need higher values for the same look.
• Higher Detail gives finer ripples and takes longer to render.

Good to know

• On HD and larger frames the default waves are faint, and Distort Source alone barely moves the image. Raise Amplitude and Detail towards their maximum and enlarge Pulse Radius, or use ANR Relief Surface as above.
• Before Start Frame the water is flat.
• The waves are smooth ripples: no splashes, and they do not react to objects in the image.
• Nothing is simulated or cached: each frame is worked out from its own time, so there is no pre-roll and frames render in any order.

Works with

ANR Relief SurfaceLights the image as a bumpy surface, from its own brightness or a Height input, with highlights and optional glass-like distortion.ANR Wave BendBends the image with a travelling sine, triangle or square wave: flag waves, wobbles, zigzags and sliced glitch looks.ANR Noise WarpWarps the image with smooth, animated noise: heat haze, underwater wobble, dreamy distortions and liquid transitions.ANR Bubble FieldFills the frame with rising, drifting bubbles with rims and highlights, for underwater shots, fizzy drinks, backgrounds and playful titles.