Houdini 20.0 Nodes Geometry nodes

Cloud Shape Generate geometry node

Creates primitive spheres used to model cumulus cloud-like shapes.

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Since 20.0

Overview

This node is useful for cloud modeling to produce the initial spherical cloud mesh for cumulus cloud like shapes.

Parameters

General

Group

The subset of the input points or primitive to use for generating the cloud shapes.

Randomization By

Controls how the random selection is seeded for parameters that are using Set Varying. Topology changes on the input geometry can shift element numbers, causing a different random selection to be used. Seed Attribute lets you provide an integer attribute to make sure the random value is not dependent on element order.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Seed Attribute

The integer type attribute to use for random selection for parameters that are using Set Varying.

Cloud Shapes

Shape

Cloud Species

Sets the cloud species for a cumulus cloud type this node will generate.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Humilis

Generates a cloud shape that is roughly wider than it is tall.

Mediocris

Generates a cloud shape that is wide as it is tall.

Congestus

Generates a cloud shape that is taller than it is wide.

Shape Offset

Controls random selection for the burst shape. Change this value to obtain different burst shapes.

Point Separation

Sets the point density scattered around the line when Number of Points is turned off. Smaller values will create denser point clouds, but will also reduce the size of the primitive spheres. Increase this value to create larger, more bulky shapes.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation for point separation. The generated values will fall between Point Separation - Variation and Point Separation + Variation.

Seed

Controls random selection for the point separation. Change this value to obtain different cloud shapes.

Initial Size

The uniform size of the cloud shape. This is a multiplier for the Length and Width parameters.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Initial Size Scale

Scales the existing pscale attribute by this amount when the menu is set to Scale Attribute. This allows you to quickly scale your cloud shape without needing to adjust the attribute value.

Variation

Sets the maximum allowed variation. Sizes will be between Initial Size - Variation and Initial Size + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Length

The length of the cloud shape along the local X-axis. Increase this value to obtain a longer cloud shape. Use the Rotation parameter to change the facing direction.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Length - Variation and Length + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Width

The width of the cloud shape along the local Z-axis. Increase this value to obtain a wider cloud shape. Use the Rotation parameter to change the facing direction.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Width - Variation and Width + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Distortion

Controls the amount of noise distortion applied to the cloud shape along the plane that is facing the up vector (given by Up Vector). This helps break up any uniform or square base shape that might be caused by values set in Length and Width parameters.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Distortion - Variation and Distortion + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Flatten Bottom

When this is turned on, all sphere primitives of the cloud shapes that reach below the given height will be moved above. The height is always the relative distance from the origin of the cloud shape (given by points as the first input) in the direction of the up vector (given by Up Vector). Use this to create billowy clouds with flat bottom.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Flatten Bottom - Variation and Flatten Bottom + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Up Vector

The vector that is facing from the bottom towards the top of the cloud shape. Use this to orient the cloud shapes onto surfaces. For example, onto a large spherical sky dome.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation in degrees. The varied direction will spread out in a cone shape from Up Vector.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Rotation

Controls the rotation in degrees around the up vector (given by __Up Vector). Use this to make the cloud shape face a certain direction.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Rotation - Variation and Rotation + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Random Scale per Shape

Random Scale per Shape

Enable this to randomize the size of each sphere primitive inside a cloud shape based on a noise pattern. This helps you create a more interesting looking cloud shape with varying billowy feature sizes.

Scale Min

Sets the minimum amount of an allowed scale by the spatial noise.

Scale Max

Sets the maximum amount of an allowed scale by the spatial noise.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Secondary Shapes

Enable Secondary Shapes

Iteratively scatters additional sphere primitives to create more interesting cloud shapes.

Iterations

Controls how many times to scatter additional primitive spheres. More iterations will create more varied, chaotic shapes.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Iterations - Variation and Iterations + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Displacement

Controls how much to move the spheres along that up vector (given by Up Vector).

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Displacement - Variation and Displacement + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Spread

Controls how much the sphere primitives should steer towards all directions.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Spread - Variation and Spread + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Random Scale per Shape

Random Scale per Shape

Enable this to randomize the size of each secondary sphere primitive inside a cloud shape based on a noise pattern. This helps you create a more interesting looking cloud shape with varying billowy feature sizes.

Scale Min

Sets the minimum amount of an allowed scale by the spatial noise.

Scale Max

Sets the maximum amount of an allowed scale by the spatial noise.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Bend

Bend

When Cloud Species is set to Congestus, enable this to bend the cloud shape.

Bend Angle

The angle in degrees to bend the cloud shape.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Bend - Variation and Bend + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Capture Distance

Controls the capture plane distance from the origin of the cloud shape (given by points as the first input) in the direction of the up vector (given by Up Vector).

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Capture Distance - Variation and Capture Distance + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Rotation

Controls the rotation of the bend in degrees around the up vector (given by __Up Vector). Use this to make the cloud shape bend towards a certain direction.

Click the randomization button on the right side of this parameter to randomize the value per incoming element. This will create/select a corresponding attribute adjust node to give you greater control over the parameter’s value.

Variation

Sets the maximum allowed variation. Sizes will be between Rotation - Variation and Rotation + Variation.

Seed

Controls random selection for variation. Change the value of the Seed if the current variation is undesirable.

Output

Shape Reduction

Fuse Distance

The maximum distance to fuse points together. Set this to remove primitive spheres that are too close to each other. Increasing this value will fuse together more and more primitives spheres into one.

Remove Below Scale

The size below which a primitive sphere needs to be removed. Use this to remove any unwanted relatively small sphere primitive.

Remove Islands

While the purpose of this node is to create a single cloud shape entity, when some settings pushed to far, you can end up with separate disconnected cloud shapes. Use this setting to keep only the largest cloud shape and discard the rest.

Attributes

Attributes

Only copy attributes whose names match this pattern. The default * copies all attributes. This will ignore copying all internally used attributes.

Randomization Attribute

When this checkbox is turned on, the burstid point attribute will be created to store the value used by the Randomization By parameter.

See also

Geometry nodes