FluxyTarget

To create a target object, go to GameObject->3D Object->FLuXY->Target.
To add a target component to an existing object, go to Component->Physics->FluXY->Target.

Adding a target component to an object will allow it to splat density & velocity onto FluidContainers. This is done by casting a ray from the container's "Project From" transform (usually a camera) to the target, and modifying fluid state wherever the ray hits the container. If no "Project From" transform is provided, the casted ray will be parallel to the container's surface normal.

Container's "Project From" set to the camera.

Container's "Project From" set to *none*, projection is parallel to the container's normal.

Note that a target's mesh (if any) doesn't afffect the shape of the resulting splat. This is controlled by the target's "Shape" texture (see below).

Containers do not do much on their own other than contain fluid, so if you want any interesting behavior you will need to use some targets for the fluid to interact with. Which targets are splatted onto which containers is controlled by Target Providers.

Let's go over FluxyTarget's inspector parameters:

Splat Material

Material used to splat density and velocity into containers. Most of the time, you should leave this at its default value. If you've written custom shaders to splat targets, you can change the material used.

Temporal Samples

Temporal supersampling used when splatting this target. Very fast moving targets will benefit from more temporal samples.

Fast rotating target, 1 sample results in visible gaps in the path.

Fast rotating target, when using 4 samples all gaps disappear.

Size

Size of the splat.

Rotation

Rotation of the splat (in degrees).

Position randomness

Percentage of randomness applied to the splat position.

Size randomness

Percentage of randomness applied to the splat size.

Rotation randomness

Percentage of randomness applied to the splat rotation.

Using random position, size and rotation.

Velocity Weight

Amount of velocity splatted onto containers. The velocity texture's blue channel, the velocity scale values and this value are multiplied together to determine the amount of velocity splatted.

Velocity Texture

Velocity texture splatted by the target. The R and G channels encode the X, Y components of a velocity vector, 0.5 (or 128, if ranged 0-255) corresponding to 0 velocity, just like a flowmap or a normalmap. The B channel is interpreted as a velocity magnitude multipler.

Velocity texture applied to a target (top left corner) and the resulting simulation, in absence of external forces. Note how the X and Y letters generate upwards velocity, but the other letters do not.

Max Relative Velocity

Caps the maximum speed of this target relative to a container. This is useful to limit how much fluid is displaced by fast moving targets.

Velocity Scale

Scales the target's velocity in each axis, expressed in the container's local space. This means the Z axis is parallel to the container's surface normal, X runs along its width, and Y along its height.

Targets with velocity scale set to 0,0,10: they only splat velocity onto the simulation when moving "into" or "out of" the container plane.

Force

Constant force applied by the target to the fluid in the container.

Left target has a force of 1,0,0, right one a force of -1,0,0. The result is two fluid jets opposing each other.

Density Weight

Amount of density splatted onto containers. The density texture's alpha channel, the color's alpha value and this value are multiplied together to determine the amount of density splatted.

Density Texture

Density texture splatted by the target. You can think of this as the shape of the "brush" used to draw on the container. Both the amount of density and velocity splatted are modulated by the density texture's alpha channel.

Src Blend

Source blending mode used when splatting density.

Dst Blend

Destination blending mode used when splatting density.

Blend Op

Blending operation used when splatting density.

See Unity's manual for a rundown of all available blend modes/operations.

The character's legs are using Src Blend "One", Dst Blend "One", Blend Op "Reverse Subtract". This will subtract the target's color from the container's, resulting in legs that "remove" fog when moving.

Color

Color tint applied when splatting density.