Lagoa Emit Volume

Creates and emits particles, filling the volume of one or more emitter objects. This compound is useful for most types of fluid effects where you want to consider the volume of a substance upon emission, or simulate a large volume of points that can break apart and show the volume's inner points.

Particles are emitted in a rest state with space between them so that they do not collide upon emission. The particle's mass value (based on the particles Mass attribute) is assumed to be 1 so that forces can act upon them accordingly.

See Setting Up Emissions in Lagoa Simulations for more information.

Plug this compound's Execute output into a port on the ICETree node or in an Execute port on a Simulation Root node.

Tasks: Lagoa/Element Creation

Output Ports: Execute

Enable

Enables this emitter node.

Emitter In Name

Plug in a volumetric object's Out Name output here. The particles fill this volume when emitted.

You can also plug a group node here, with each volumetric emitter object defined in the group.

Element Generation

Resolution Per Unit

To calculate the emission of elements, the emitter's volume is divided into Softimage units, each representing a fixed space of 10 cm.

This parameter sets the density (points per unit ratio) of the element, adjusting the size and number of points for each unit of the emission volume. It tries to put in as many points of mass as can fit inside the emitter volume's space. The points are arranged into a neat grid within this volume upon creation.

A value of 1 means that one point is created per unit inside the volume. A lower value means that the density that is trying to be achieved per unit will require more (and smaller) points to fill the same volume.

See Setting Up Emissions in Lagoa Simulations for more information.

Max Cells

Maximum number of cells that can be created. Cells are subdivisions of the units. The default maximum is 1,000,000 cells. Using a Resolution Per Unit value of 0.01 creates 1,000,000 cells.

Generate

The way in which the points are generated inside the volume:

Uniform Placement places points in a grid formation. This is the default emission form.
Hex staggers the points slightly so that they are not in a strict grid. This is useful for having an emission that doesn't look perfectly aligned. Hex also makes it easier for an element to break apart due to rotational motion, such as an elastic structure with a low breaking point.
The Tetrahedral option creates four times more points around each cell center. This results in smaller points with little space between them, so you can create highly incompressible matter this way or very high friction materials.

This is useful for creating fluid effects, when you need many particles, but you don't want to lower the Resolution Per Unit value. It's also the best choice if you want to simulate volume-preserving soft bodies.

Tetrahedra may require more substeps because they have more resolution by default.


Uniform Placement	Hex	Tetrahedral

Emitter

Emit Rate

Emits the points in either way:

Once at Frame, which emits the particles only once at the Emit at Frame value you set below.
Every Frame, which emits the particles at every frame of the simulation.

Emit at Frame

The frame at which the particles are emitted if you selected Once at Frame as the Emit Rate option.

Global Time

If this option is on, Emit at Frame is relative to the scene's timeline. If it is off, the frame is relative to the simulation range set in the Simulation Time Control Property Editor.

Fitting

Perform Space Check	Checks for available space between points before emission, making sure that there is enough space so that they don't collide upon emission. If this option is off, the particles may "explode" in all directions upon emission.
Fill Space	Tries to fill the space in the emitter volume (points are in a non-rest state), spreading the points in all directions to fit the space. This can create air spaces between the points, making the element behave differently from when this option is off. The air spaces are removed at some point, and it may appear as if the element is losing volume, but it's just because of the loss of the air spaces at emission.
2D	Creates a two-dimensional grid (X,Y) of the point cloud instead of three-dimensional. This is used mostly for testing for fluids because it's faster than calculating the full 3D volume when you may have thousands of points.
Invert Volume	Reverses the directions of the emitter volume's normals to emit points outside of the volume instead of inside the volume.
Closed Volume	Select this option to treat the volume emitter object as a closed shape (no holes).

Display

Color From

The color of the points at emission coming from either:

Custom: The color you set specially, such as by plugging in a node here or in the Material node that controls the particle color.
Emitter Display Property: The color you set with the Color value below.

Color

The display color of the points only at emission.

This color is overridden when you select the Set Color option the color set in the Material compound (see Lagoa Main Material). Setting the color in the Material compound lets you update the point color at every frame instead of only at emission.

Shape

Shape of the particles at emission. This uses the particle's Shape attribute.

You can also used instanced geometry as the particle shape.

Simulator Settings

Node Type	Make sure this is set to Real. The other values are available for future functionality.
Cluster ID	Sets the cluster for points emitted from the connected object. Points in clusters with different IDs will not attach to each other during the simulation.
Cluster at Emission	Considers the particles at emission time to be a separate cluster so that at every frame a new cluster is created independently from the existing ones. See Creating Elastic Clusters for more information.
Cluster by Geometry	With elastic structures, this option considers each geometry to be a separate cluster that does not merge with the others. For example, you may want to emit two different volumes that are in their own clusters instead of merging them together. To merge clusters, they need to have the same Cluster ID, then select the Solve Plasticity option in the Lagoa Simulate Multiphysics node.
Constrainable	Toggles the activeness of the particles' constrainability. Particles that are constrainable can stick to a collision object's surface (contact links — see Lagoa Main Material) and can have constraints turned on/off.
Phase	The Phase ID of the particles where they are initialized. This ID must match the Emit node's accompanying Lagoa Phase node.
Initial Force	The force direction given to the particles at emission. This can be in any direction (XYZ).
Execute on Emit	Any node plugged in here is executed only at emission.

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