RBD Configure geometry node

Packs and creates attributes describing rigid body objects.

On this page	RBD Configure SOP Parameters Visualization Units Bounds Attributes Bullet Data Physical Attributes Constraints Emission
Since	18.0

This SOP packs the input geometry and proxy geometry if unpacked, and creates attributes on the simulation geometry (the geometry if no proxy geometry available) to drive the Bullet Packed objects that they represent.

RBD Configure SOP ¶

The RBD Configure SOP lets you set up properties individually for different sets of RBD objects. The Group parameter allows you to select a group of pieces (such as wood pieces) and set up whether they're Active, Animated, Deforming, or Sleeping. It also lets you set up what type of collision shape they should use, how much collision padding there should be, any speed limitations etc.

The Physical Attributes controls are very useful, as there are many predefined density, friction, and bounce settings for different material types. For example, if your material Type is Wood , you can choose between: Balsa Wood, Beech, Birch, Cedar, Mahogany, Maple, Oak, Pine, or Plywood. This will automatically fill in the appropriate Density, Friction, and Bounce coefficients that you would get from engineering textbooks, which will give you a head start on getting results that are physically realistic to go along with the fracturing methods.

There are also many Visualization options for the properties you're setting up. For example, if you're setting up which pieces are active, you can choose to visualize the Active pieces. You can also change the Bounding Type to Bounding Box and enable the Use Bounds option to manually control which pieces are active or not using a bounding box in the viewport.

There’s also a built in Exploded Scale parameter at the top of the viewport for exploding outwards for a more detailed visualization.

Note

You could alternatively use your own bounding geometry by connecting it to the 4th input of this node.

Note

It is recommended to use this SOP at the bottom of the node chain as once the geometry is packed, edits to the geometry and proxy geometry are no longer possible without first unpacking.

Note

While groups are promoted to the packed geometry, inside and outside groups are omitted as these typically do not encompass the entire pieces' geometry and will yield incorrect results when promoted.

Groups and attributes are preserved and available when unpacking the geometry.

Parameters ¶

Visualization ¶

Visualize

None

No visualization.

Active

If the active attribute is set, packed fragments with the active attribute set to 1 are displayed in green, 0 in black.

Animated

If the animated attribute is set, packed fragments with the animated attribute set to 1 are displayed in red, 0 in blue.

Deforming

If the deforming attribute is set, packed fragments with the deforming attribute set to 1 are displayed in red, 0 in blue.

Sleeping

If the bullet_sleeping attribute is set, packed fragments with the bullet_sleeping attribute set to 1 are displayed in red, 0 in blue.

Bounce

A histogram is displayed showing the range of bounce values and the corresponding colors on the geometry.

Density

A histogram is displayed showing the range of density values and the corresponding colors on the geometry.

Friction

A histogram is displayed showing the range of friction values and the corresponding colors on the geometry.

Rotational Stiffness

A histogram is displayed showing the range of inertialtensorstiffness values and the corresponding colors on the geometry.

Pinned

If the __pin attribute is set, packed fragments with the __pin attribute set to 1 are displayed in red, 0 in blue.

Exploded Scale

The amount to expand the visualized pieces. Each piece is moved proportionally to its distance to the center. A value of 1 will approximately double the size of the object.

Units ¶

Unit Mass (kg)

The intended mass scale for applying density.

Unit Length (m)

The intended length scale for applying density.

Bounds ¶

Bounding Type

Shape of bounding volume.

Size

Size of bounding volume.

Center

Center of bounding volume.

Rotation

Rotation of bounding volume.

Attributes ¶

Transfer Attributes

Specifies a list of attributes to transfer to the packed geometry.

Attributes

Attributes can be set on a subset of the incoming geometry using the Group parameter. This allows to set various attribute values to different subsets of the geometry with a single node.

Create Path Attribute

Assign “op:” followed by the full path to the RBD Configure SOP as the path attribute value to the newly created packed primitives.

Create Packed Fragments

When disabled, creates packed geometry instead of packed fragments. When emitting RBDs, packed geometry will perform better than packed fragments.

Group

The primitives in the simulation geometry to edit attributes for.

Bullet Data ¶

Add Active

Creates and sets the active attribute.

Active

Sets the active attribute to the specified value. Default is 1.

Use Bounds

Set the attribute value to the specified value to primitives within the specified bounds. Primitives outside the bounds will be set to the inverse value.

Add Animated

Creates and sets the animated attribute.

Animated

Sets the animated attribute to the specified value.

Add Deforming

Creates and sets the deforming attribute.

Deforming

Sets the deforming attribute to the specified value.

Add Sleeping

Creates and sets the bullet_sleeping attribute.

Sleeping

Sets the bullet_sleeping attribute to the specified value.

Add Enable Sleeping

Creates and sets the bullet_want_deactivate attribute.

Enable Sleeping

Sets the bullet_want_deactivate attribute to the specified value.

Add Sleep Linear Threshold

Creates and sets the bullet_linear_sleep_threshold attribute.

Sleep Linear Threshold

Sets the bullet_linear_sleep_threshold attribute to the specified value.

Add Sleep Angular Threshold

Creates and sets the bullet_angular_sleep_threshold attribute.

Sleep Angular Threshold

Sets the bullet_angular_sleep_threshold attribute to the specified value.

Add Geometry Representation

Creates and sets the bullet_georep attribute. Default is convex hull.

Geometry Representation

Sets the bullet_georep attribute to the specified value.

Note

When configuring collision geometry, use this to differentiate between various geometry representations that best fit each collider.

Add Collision Padding

Creates and sets the bullet_collision_margin attribute.

Collision Padding

Sets the bullet_collision_margin attribute to the specified value.

Add Shrink Amount

Creates and sets the bullet_adjust_geometry attribute to 1 and creates the bullet_shrink_amount attribute.

Shrink Amount

Sets the bullet_shrink_amount attribute to the specified value.

Add Collision Group

Creates and sets the collisiongroup attribute.

Collision Group

Sets the collisiongroup attribute to the specified value.

Add Collision Ignore

Creates and sets the collisionignore attribute.

Collision Ignore

Sets the collisionignore attribute to the specified value.

Min Activation Impulse

The minimum impulse from a collision that will cause the object to switch from inactive to active. The activation occurs at the instant that the collision occurs. The activationignore attribute can be used to prevent the object from being activated by collisions with particular objects.

Activation Ignore

If Min Activation Impulse is enabled, collisions against any objects which match this pattern will not cause the object to be activated. The pattern uses the same syntax as the collisionignore attribute.

Add Allow Initial Overlap

If enabled, the Allow Initial Overlap setting is applied to the objects in the group.

Allow Initial Overlap

When the solver sees an object for the first time, it checks whether that object is initially overlapping with any other objects in the simulation and prevents any such pairs of objects from being forced apart. If this is disabled, initially overlapping objects will be moved apart to resolve the collisions.

Tip

To resolve collisions between initially overlapping objects without adding velocity, ensure that Split Impulse is enabled on the Bullet solver and set the Penetration Threshold to 0.

Min Sticky Collision Impulse

The minimum impulse from a collision that will cause this object to stick to another object. This value must be greater or equal to 0 for the objects to stick.

Max Sticky Collision Objects

The maximum number of other objects that this object can be stuck to. A value less than or equal to 0 allows this object to be stuck to any number of other objects.

Max Sticky Collision Points

The maximum number of anchor points (constraints) that can be used to stick this object to another object.

Sticky Collision Ignore

Sticky collisions will not occur when colliding with any objects that match this pattern. The pattern uses the same syntax as the collisionignore attribute.

Add Speed Min

Creates and sets the speedmin attribute. Default is -1 (no effect).

Speed Min

Sets the speedmin attribute to the specified value.

Add Speed Max

Creates and sets the speedmax attribute. Default is -1 (no effect).

Speed Max

Sets the speedmax attribute to the specified value.

Add Spin Min

Creates and sets the spinmin attribute. Default is -1 (no effect).

Spin Min

Sets the spinmin attribute to the specified value.

Add Spin Max

Creates and sets the spinmax attribute. Default is -1 (no effect).

Spin Max

Sets the spinmax attribute to the specified value.

Add Acceleration Max

Creates and sets the accelmax attribute. Default is -1 (no effect).

Acceleration Max

Sets the accelmax attribute to the specified value.

Add Angular Acceleration Max

Creates and sets the angaccelmax attribute. Default is -1 (no effect).

Angular Acceleration Max

Sets the angaccelmax attribute to the specified value.

Physical Attributes ¶

Type

Select a predefined material type for material based density, bounce and friction presets.

Add Density

Creates and sets the density attribute.

Density (kg/m3)

The preset-based density displayed in kg/m3 unit.

User Density

Override the preset-based density, specified in kg/m3 unit.

Var

Denotes a percentage increase/decrease from the user base input. For example, a threshold value with a value of 1000 and a variance set to 0.1 will result in values between 900 and 1100, while a variance of 1 will result in values ranging from 0 to 2000.

Add Bounce

Creates and sets the bounce attribute.

Bounce

The preset-based bounce.

Note

The preset value is approximated and not physically accurate.

User Bounce

Override the preset-based bounce.

Add Friction

Creates and sets the friction attribute.

Friction

The preset-based friction.

Note

The preset value is generalized as friction is specified as a friction coefficient between 2 materials.

User Friction

Override the preset-based friction.

Add Rotational Stiffness

Creates and sets the inertialtensorstiffness attribute.

Rotational Stiffness

Sets the inertialtensorstiffness to the specified value.

Constraints ¶

Add Pin

Creates constraint geometry of length 0 configured to use a constraint of type set by Type. Creates and sets the __pin attribute to the specified value to drive a sop solver and force the pieces to stay in place.

When set to 0, the objects will not be pinned and constraints will not be created. When set to 1, the objects will be pinned in place and Pin constraints created.

Type

Hard (Deprecated)

Creates Hard Constraints. The constraint name is set to Pin.

Glue

Creates Glue Constraints. The target objects for the glue constraints are named __gluepin/ followed by the name of the pinned pieces. These target pieces will be generated dynamically in the RBD Bullet Solver SOP with no geometry representation.

Soft

Creates Bullet Soft Constraints.

Emission ¶

Add RBD Bullet Emit

Creates a rbdbullet_emit point attribute to control which pieces will be emitted and which pieces will be treated as regular RBDs with the RBD Bullet Solver SOP when the Emit option is enabled. This allows you to mix regular RBDs, which can be animated/deforming with emitted RBDs.

RBD Bullet Emit

When set to 0, the objects will be treated as regular, non emitted RBDs. When set to 1, the objects will be treated as emitting RBDs and will emit on every frame they are connected to the RBD Bullet Solver.

RBD Configure SOP ¶

Parameters ¶

Visualization ¶

Units ¶

Bounds ¶

Attributes ¶

Bullet Data ¶

Physical Attributes ¶

Constraints ¶

Emission ¶

Geometry nodes