Houdini 21.0 Nodes Geometry nodes

RBD Car Transform geometry node

Transform a fractured car.

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Since 21.0

This node allows you to transform an RBD fractured car using a simple (unfractured) car rig or its simulation points. It can optionally realign the wheels and adjust the steering cone twist constraints in order to avoid double transforms and wheels spinning incorrectly during subsequent simulations.

Inputs

Geometry

The RBD Car Fracture render geometry to transform.

Constraint Geometry

The RBD Car Fracture constraint geometry to transform.

Proxy Geometry

The RBD Car Fracture proxy geometry to transform.

Simulation Points or Animated RBD Car

The RBD Car Rig simulation points output from an RBD Bullet Solver, or the transformed RBD Car Rig packed geometry. This can be done with a RBD Transform SOP or RBD Car Follow Path SOP.

Note

If the RBD Car Rig geometry at the start of the simulation doesn’t line up with the fractured geometry, the restxform point attribute can be output from the RBD Bullet Solver and used to fix any misalignment.

Parameters

Re-Align Wheels

If the input RBD Car has steering and wheel animation (after an RBD Car Follow Path SOP with Animate Wheels and Suspensions on, or following a driving simulation), you will need to re-align the wheels and adjust the steering. Otherwise, the simulation may apply double transforms, causing the wheels to spin around the wrong axis.

Animation Offset

Enable overriding the car’s wheel orientation (steering) for fine tuning or for controlling the steering in further simulations.

Steer

Adjust the wheel direction by steering left (-1) to right (1).

Blend

The amount to blend the manual steering in.

Simulation Start Frame

When overriding steering, enable Constraints’ Override Attributes on the RBD Bullet Solver SOP and set the value to goal_*_axis to ensure the steering animation carries into the next simulation. The animated constraint attributes must be defined relative to the first simulation frame, or to the first frame where the constraints appear in the solver.

See also

Geometry nodes