Liquid Shader

How the Liquid Shader Works

The liquid shader uses Spring weight that spins around and towards a point above the player character to generate a normal vector via script. The normal is used to create a ray, that finds the angles to align the rotation of the liquid. The Normal is passed to the shader, and the mesh is compressed to a height based on a variable and angle based on the normal. Vertices that would be compressed outside of the spherical mesh are pushed inwards. The velocity of the character creates a Sine wave that the script passes to a compute shader. The compute shader applies the wave to a series of 16x16 springs that pull on eachother. The positions of these springs are used to generate a 2D texture in black and white which the script passes on to the shader. The shader applies this texture to the flat top of the mesh to deform it and create waves.

List of currently implemented variables

SHADER Variables

- Wave Density

The wave density affects the number of waves that appears on top of the water's surface

- Normal Contrast

Used for tweaking the normals of the waves

- Height

Change the height of the liquid

- Sphere Radius

This float is used for the cropping of deformations outside of the bottle's bounds, the radius should be kept at 0.385 at this time.

- Plane Normal

Automatically generated angle for the top of the liquid using a ray pointing to a swinging weight. Must be normalised lest the surface be concaved.

- Rotate & Rotate2

Automatically generated based on the character's look direction. Used to reorientate the liquid and waves to face the character's direction.

- Alpha

This value changes the transparency of the liquid

- Smoothness

- Occlusion

- Specular Colour

- Wave Deform Texture:

This texture is automatically generated via a compute shader, and applies a deform to the top plane of the liquid to simulate waves

- Foam Blend Blend Sharpness and Foam Height

These values are intrinsically linked to change the look of the foam, these will eventually be controlled by script to adapt the foam to changing heights as values will need to be adjusted to get the perfect look at all times.

- Foam Speed

The rate at which the foam texture if applied moves

- Foam Colour

The - colour that the foam texture will be modified to.

- Foam Texture

The texture projected on top of the liquid to emulate foam.

Shader Liquid Subgraph Controls

Triplanar subgraph applied to XY, YZ and XZ planes. Intention is to make it easy to swap out without changing the physics.

- Liquid Colour

The Colour that the subgraph will be changed to

- Brightness

The brightness of the subgraph's emission

- Tiling

The density of the XY and YZ planes

- Top Tiling

The density of the XZ plane

- Texture Speed

The speed of the subgraphs' texture

- Texture Ani Blend

Point at which the subraph's animation fades to repeat

- Contrast

Contrast of the subraph

SCRIPT Variables

Damping

The rate at which the wave wobbling returns to neutral

Spring Stiffness

How easily the waves are manipulated

SPRING WEIGHT VARIABLES

The Spring Weight in the hierarchy is what controls the wobbling of the liquid, adjusting the variables in the spring weight will change the way it behaves, and as such the liquid will follow.

Planned Features

• Effervescent bubbles
• Agitation based foam
• More realistic foam, with deformation
• Better Waves
• Better Colour customization

Known Issues

• Wave deformation changes water level slightly
• Cropping slightly off