Lagoa Main Material

 
 
 

The Lagoa Main Material node is the standard material compound used for setting the material properties of a point cloud. It exposes all supported attributes that can be activated and calculated in the Lagoa Simulate Multiphysics compound, which is the simulator.

Plug this compound's Execute output into an Execute port of the Lagoa Phase node.

Tasks: Lagoa/Material Type

Output Ports: Execute

Element Display

Set Color

Applies the Color defined below to points that have this material type. This makes it easy to distinguish among points when multiple materials are applied to the same point cloud.

Selecting this option overrides the Color that you have set in the Lagoa Emit compound (see Lagoa Emit Volume).

Color

Select a color to be applied to the points when the Set Color option is on.

Solver Properties

Kernel Radius

Defines how this material searches for its neighboring points. If you change the settings for this parameter, you are managing the material compression properties, which is only recommended for advanced usage.

Although this parameter is defined per material, it is strongly recommended that all materials in the same ICE tree use the same Kernel Radius element to ensure a more accurate representation of the particles.

 

  • Automatic: The point considers an area of its own size * the spherical radius of a particle as the simulation space for compression. This means that the point can interact with points and surfaces with a spherical range of itself. For the Pressure settings, for example, this would allow points to attract/repulse/use surface tension up to two points around itself on every dimension, so up to 27 surrounding cells are used. Automatic is the only type that can allow incompressible fluid volumes.

  • Spherical Radius: This allows points to interact when they get close to the center of another point. This is useful for creating highly compressible points, allowing you to use many more points within a volume (higher density). For more inelastic collisions, it's only useful for creating very fast or simple splashes where you want to have more points, or when the physical size of a point doesn't matter much.

  • Spherical Diameter: The point uses its own diameter so that it will interact only when it touches another point's surface. This is useful for rigid points, where the interactions are limited to inelastic collisions. In a fluid volume, this will cause visible compression.

  • Custom Radius: In special cases where you need to define the simulation space, this option lets you define the distance range to be considered for each point using the Custom Radius value you set below. This is useful if you are familiar with how the simulator works and want to design a material that can attract point masses that are very far away, or that will force incompression defined within this distance.

  • Spherical Diameter* Custom: The point can interact with points that are within an area of its own diameter * the Custom Radius value you have set below.

Custom Radius

If you selected the Custom Radius or Spherical Diameter * Custom option above, enter the distance in Softimage units of the simulation space to be considered for point compression.

Interfaces

Material Collision Offset

Creates an offset between points that have this material and collision objects.

You can also select the Offset Method in the Lagoa Simulate Multiphysics node which allows you to define an offset from the collision objects globally for all materials used in this ICE tree.

Surface Friction

How much friction that points with this material have when in contact with a collision object.

This value is added with the Surface Friction value you have set for the collision object in its Lagoa Set Collision Data node.

Select the Enable Static Friction option in the Lagoa Simulate Multiphysics node to use this value when calculating the whole simulation.

Pressure Settings

Pressure is the field that governs the incompressibility of fluids. The material's Pressure settings define a wide range of pressure reactions, letting you model things such as expanding, compressing, and tensioning effects on both liquids and elastic objects.

See Pressure for more information about pressure.

In Lagoa, pressure always tries to reach a rest state, which is based on the Surface Tension parameter. The pressure model also uses two pressure coefficients that act in two ways: one is an attraction (Internal Pressure), and the other is a repulsion (External Pressure).

Solve Pressure

Activates the solving of the Pressure parameters for this material.

Select the Enable Pressure option in the Lagoa Simulate Multiphysics node to use the Viscosity settings when calculating the whole simulation.

Surface Tension

Sets the degree of tension between points on an element's surface which causes the element to compress to the smallest possible area. This makes particles form into a spherical shape when grouped together.

Higher values cause the surface of the fluid to become smooth, making the particles get as close together as possible and as smooth as possible (think of honey). If you increase the surface tension, you should lower the Inelasticity value because opposing forces can make the particles flicker.

Lower values let the fluid move more freely because the particles do not stay together that much (think of water).

See Surface Tension for more information.

Internal Pressure

Internal pressure acts like an attraction between points that are within a certain distance of each other. High values causes points to group together, such as to form droplets, filaments, and sheets. This is visually related to surface tension and thickening effects of a fluid.

Values above 1 are not recommended because they are create fluids that are impossible to have in nature, and they can cause instabilities, which means that you will need to increase the Substeps value in the Lagoa Simulate Multiphysics node.

See Pressure for more information.

External Pressure

This pressure tries to retain the shape of the whole element's volume by pushing the points away from each other (like a repulsion force) to prevent compression, which is especially noticeable in fluids.

To have compressible fluid, make the Internal Pressure value smaller than the External Pressure value. The more compressible the fluid is, the more space is between the points, depending on the Resolution when they are emitted. In this case, the point volume will look sparse because the points are trying to reach their ideal distance quickly. This is a visible effect with gases where molecules tend to be very far apart.

Very high values create very stiff fluids that cannot be compressed. Lower values create fluids that are almost completely free to move away from their neighbors, like gases, and just stick together again if they get very close together.

This value should always be 1 or higher. However, values that are too high (such as 15 or 20) can cause jittering, which means that you will need to increase the Substeps value in the Lagoa Simulate Multiphysics node.

Interfaces

Boundary Pressure

Extends the pressure computation to the boundaries. This is the pressure that is exerted between the collision objects and the points with this material. You can imagine the pressure as the space (a boundary) between these two elements.

You can control how much pressure that the points receive from the surfaces of the collision objects, but not vice versa.

Select the Enable Pressure option in the Lagoa Simulate Multiphysics node to toggle the solving of the Boundary Pressure parameters for all materials used in this ICE tree.

Internal Interface Pressure

The pressure coefficient of particles of one material when they comes in contact with particles of another material. You can imagine the pressure as the edge between particles with different materials.

The effects of using this parameters can only be seen when more than one phase is being used — see Lagoa Phase.

The higher this value, the more pressure the points with this material exert on the points with other materials when they come in contact.

This pressure defines how much they "float" on top of each other or blend together, such as oil and water particles. Changing the pressure creates the movement of particles with one material to the area of particles with another material.

Viscosity Settings

Viscosity is the level of resistance to flow in a fluid. It smooths out the velocity by exchanging velocity between points using a Gaussian distribution method.

Solve Viscosity

Activates the solving of the Viscosity parameters for this material.

Select the Enable Viscosity option in the Lagoa Simulate Multiphysics node to use the Viscosity settings when calculating the whole simulation.

Viscosity Multiplier

The amount of viscosity the points with this material have when they are in contact with themselves or with points that have other materials.

Lower values provide little resistance to flow, creating the effect of a watery fluid; higher values provide more resistance to flow, creating a thicker, more syrupy fluid.

Viscosity Contrast

Sets the threshold at which a liquid reaches its viscous condition. Low values allow liquids to become viscous more easily.

For example, to change between viscous and non-viscous conditions, you can keep the Viscosity Multiplier value the same, then simply adjust this parameter's value.

Inelastic Settings

Inelasticity is the amount of friction that points have between themselves, allowing the modeling of straight rigid collisions between the points. In the case of cloth materials, they use inelasticity to solve self-collisions.

You can set the Inelastic Substeps value for only the Inelastic Settings in the Lagoa Simulate Multiphysics node. Increasing this value can create more accurate simulations when solving inelastic behavior, such as penetration, friction between points, etc. See Setting the Simulation's Substeps for Accuracy for more information.

Solve Inelastic

Activates the solving of the Inelastic Setting parameters for this material.

Select the Enable Inelastics option in the Lagoa Simulate Multiphysics node to use the Inelastic Settings when calculating the whole simulation.

Inelastic Collision

The amount of inelasticity the points have when when in contact with each other. Higher values makes the points collide more rigidly: the stiffness of the points cause them to bounce off each other's surfaces.

Inelastic Friction

How much friction that points have when in contact with each other. This allows for points piling up on each other in a collision, such as for dirt.

Friction Flow Rate

The ability of a point to slip and flow from another point friction contact. This is the shearing flow of inelastic colliding points.

Thickness

Creates a buffer around the points. The value is relative to the point size. It is computed such that the thickness of a point = point Size + (the point Size * Thickness).

Elasticity Settings

Elasticity is the ability of a material to return to its original shape after a deformation has occurred. The Elasticity parameters here create a structure that is controlled by spring-like connections between points. This structure can have a breaking point.

These parameters can also allow the modeling of stress, plastic tensors. Plasticity occurs when a deformation is too big for a structure, and the shape cannot return to its rest pose.

See Elasticity for more information.

You can also create separate clusters of elastic structures — see See Creating Elastic Clusters for more information.

You can set the Elastic Substeps value for only these settings in the Lagoa Simulate Multiphysics node.

TipTo see the elastic structure, select the Display Structure option in the Lagoa Simulate Multiphysics node.

Solve Elastic

Activates the solving of the Elasticity Settings parameters for this material.

Select the Enable Elastics option in the Lagoa Simulate Multiphysics node to use the Elasticity settings when calculating the whole simulation.

Elasticity at Boundaries

Activates the solving of the links between points and collision surfaces.

These links are affected by the Elasticity parameters in the Lagoa Set Collision Data node of each collision object.

Elasticity

How much elasticity this material has in general.

This value determines how much the links in the structure try to recover after being deformed. A higher value allows for a quicker recovery from the deformation.

Elastic Breaking Point

How much deformation is necessary to break the links between the points of this material. This is measured in radius and is relative to the resolution of the point formation.

The range is from 0 to infinity, where:

  • A value of 0 is the state of the contact links at creation point, which means that anything will break the connection.

  • A value of 0.1 means that 10% of a change in shape can occur.

  • A value of 1 means that 100% of change in shape can occur.

This percentage is in relation to the shape of the point itself when it was first initialized or emitted.

Make sure to select the Allow Tearing option in the Lagoa Simulate Multiphysics node if you want to use the Elastic Breaking Point value in the simulation.

Stretch Resistance

How much the elastic structure resists stretching/bending.

These are the parallel links that are made horizontally and vertically between the points, creating a tile-like pattern in the structure. These links try to prevent the object from stretching.

Low values allow the material to deform without resistance, while higher values prevent it from stretching.

Shear Resistance

How much the elastic structure resists shearing, which is a crosswise motion on the material.

These are the diagonal links that are made between points, like a fish net. The links try to keep the structure's shape by resisting deformation.

Damping

Reduces the effect of the elasticity (slows it down). This helps stabilize a simulation when the forces are too strong, and there are not enough Substeps or Elastic Substeps set for the material.

Custom Elastic Range

Allows elasticity to occur over a larger area than the automatic area dictated by the Kernel Radius type that you have selected.

For example, if you want elasticity in the middle of a body, you can set a custom range so that it also has an effect on points that are farther away from the area where elasticity was applied or where the deformation occurred.

This is useful for modeling very elastic materials that can snap back from a very large deformation, such as a bungee cord or the rubber part of a slingshot.

If you are doing highly elastic materials, the Elastic Breaking Point value must be higher to prevent the structure from breaking too easily.

Custom Range

The size of the custom elastic range. This is a radial value relative to the size (resolution) of the point.

Select the Solve Custom Elastic Range option in the Lagoa Simulate Multiphysics node to use this value when calculating the whole simulation.

Plastic Flow

After a certain amount of deformation, an elastic structure can lose its shape and not be able to return to its original states. Plasticity models this change in the rest state of the shape. If the deformation is large enough, the decay of plasticity take place.

If elastic structures can be reassembled together in a different configuration, such as with elastic clusters, you can select the Solve Plastically option in the Lagoa Simulate Multiphysics node. This allows a point to modify its own elastic connections during the simulation.

Select the Solve Plastic Flow option in the Lagoa Simulate Multiphysics node to use the Plastic Flow settings when calculating the whole simulation.

Plastic Yield

The threshold at which an elastic structure starts to become plastic.

Plastic Expansion

The amount of shape that the elastic structure will lose when it's undergoing expansion.

Plastic Compression

The amount of shape that the elastic structure will lose when it's undergoing compression.

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