VDyna Physics Engine

From high-fidelity models, hardware-in-the-loop to real-time control

What is VDyna?

VDyna is a cross-platform, C++ library for multi-body dynamics simulation. At its core is a high-performance kinematics and dynamics solver. The library features specialized wheel-terrain interaction models for vehicle analysis, built-in interfaces for control systems and hardware-in-the-loop, and modules for fluid-solid interaction problems. For visualization, it offers flexible rendering backends, including integration with VulkanSceneGraph for visualization and Unreal Engine for high-fidelity, real-time applications.

MBS and SPH Coupling

Seamless integration of Multi-Body Dynamics and Smoothed Particle Hydrodynamics for high-fidelity fluid-structure interaction simulation.

Expert-Level Team: Our support engineers are senior application specialists with solid theoretical foundations and extensive cross-industry project experience, enabling them to understand the root cause of issues.
Rapid Response Mechanism: We offer clear service channels (phone/email/online ticket) with tiered response time commitments to ensure your issues receive timely attention.
Knowledge Base & Solution Library: Our internal knowledge base, built on massive case studies, allows for rapid matching to historical solutions or provision of validated reference approaches.

solver/sph_mbs_coupling.cpp

// SPH 与 MBS 双向耦合求解器核心类
class CoupledSolver {
public:
    void solveStep(double dt) {
        // 1. 计算流体(SPH)压力与粘性力
        sph_system.computeForces();

        // 2. 处理流固耦合边界条件
        for (auto& p : sph_system.particles) {
            if (mbs_system.checkProximity(p.pos)) {
                Vector3 f_fsi = calculateFSI(p, mbs_system);
                mbs_system.applyForce(f_fsi, p.pos);
                p.force -= f_fsi;
            }
        }

        // 3. 多体动力学积分推进
        mbs_system.integrate(dt);

        // 4. 更新粒子状态
        sph_system.updatePositions(dt);
    }
};

How We Achieve Real-time Performance?

Our multi-body dynamics engine leverages advanced algorithms and hardware acceleration to deliver real-time performance for simulation and control applications.

Advanced Dynamics & Constraints: Utilizing Featherstone's recursive algorithm to optimize dynamics solving with O(n) complexity. Combined with our Non-linear Constraint Solver, we accurately simulate complex mechanical joints.
High-Frequency Collision Detection: Integrated Continuous Collision Detection (CCD) and penalty-based contact models support high-frequency detection for terrain meshes.
Native GPU-Accelerated Solver: A CUDA-based parallel sparse matrix architecture distributes Jacobian computations across thousands of cores.

Core Engine Active State

Solver Performance

Jacobian 0.12ms

Projection 0.34ms

1000Hz

Frequency

Stable

Integrator

DynamicsSolver.cpp

// Core Pipeline

void StepSimulation(double dt) {

collision_engine.detect_contacts(scene_nodes);

mbd_solver.resolve_constraints(ITER_MAX);

}

High-Fidelity Visual Rendering

Advanced rendering engine integration for real-time visualization, connecting simulation data directly to high-fidelity graphics pipelines.

VulkanSceneGraph Integration: Robust 3D visualization optimized for massive engineering datasets and low-latency interaction in desktop environments.
Unreal Engine 5 Live-Link: Seamlessly synchronize physical state data with UE5 for AAA-grade realism, utilizing Nanite and Lumen technologies.

U

Live-Link

UE5 Connected

Framerate

60.0 FPS

RenderingBridge.cpp

// 可视化同步管线（VSG 实现）

void UpdateVisuals(SceneData data) {

vsg_transform.matrix = data.transforms;

// 标记矩阵数据已变更

vsg_transform.matrix->dirty();

unreal_bridge.stream_to_ue5(data.physics_state);

}

VSG Native Graphics Core Active

Rapid Modeling Templates

Ready-to-use vehicle modeling templates that accelerate model creation with pre-built configurations for wheeled and tracked platforms.

Wheeled Vehicle Template: Standardized components for suspension systems, steering geometry, and powertrain, configurable for any N-wheeled architecture (4x4, 6x6, etc.).
Tracked Machinery Template: High-fidelity track-soil interaction models for excavators, tanks, and agricultural equipment, supporting multi-body track link simulation.

VehicleConfig.py

# Initialize Wheeled or Tracked Vehicle

vehicle = DynamicsCore.create(

type="WHEELED_4X4",

mass=1800.0, # kg

suspension=Template.MACPHERSON

);

# Attach powertrain & soil model

vehicle.attach_powertrain(EV_DRIVE);

vehicle.set_soil_type(SOIL_SANDY_LOAM);

# Start Real-time Worker

vehicle.spawn_worker(target_fps=1000);

READY-TO-USE

Wheeled Base

Tracked Base

Seamless Integration & API

Open architecture with comprehensive API support, enabling deep integration into existing engineering workflows and simulation pipelines.

Universal C++ / Python API: Direct access to state vectors, force injection, and kinematic properties through high-performance bindings, allowing for deep custom development.
Standard Industry Bridge: Built-in support for FMI/FMU standards, ROS2 nodes, and UDP/Shared Memory protocols for ultra-low latency data exchange.

Dynamics Core

Unreal / Unity

ROS / ROS2

Simulink HIL

Python SDK

API Status: Ready

Solver Methodologies

Constraint solvers find the impulses needed to satisfy joint and contact requirements. Our engine supports both iterative approaches for real-time speed and direct solvers for high-fidelity accuracy.

Technical Formulation: Built upon a non-smooth dynamics framework that models joints, contacts, and friction through Nonlinear/Linear Complementarity Problems (NCP/LCP) and Variational Inequalities. It utilizes projected iterative methods (e.g., Krylov subspace methods and Projected Gauss-Seidel) with custom preconditioning.
Engineering Value: Delivers physical consistency and force balance for over-constrained mechanisms and closed-loop kinematic chains. Eliminates artificial joint drift, compliance artifacts, and contact chatter commonly found in penalty-based or purely speed-focused engines.

Core Capabilities

At its core, VDyna features a multi-physics engine that delivers engineering-accurate simulations of rigid and flexible bodies, complex constraints, and material interactions in real-time or faster-than-real-time.

Specialized Toolkits for Advanced Applications: Accelerate domain-specific development with dedicated modules for vehicle dynamics (including detailed tire and suspension modeling), robotic manipulators and mobile platforms, and heavy equipment interacting with deformable terrain and granular materials.

Open Architecture for Customization & Automation: Go beyond the GUI. VDyna is built for integration, offering a powerful Python API for scripting custom behaviors, automating workflows, and embedding the simulator into larger toolchains. A comprehensive C++ SDK is available for deep, performance-critical extensions.

Seamless Ecosystem Integration: Connect your simulations to the tools you already use. VDyna provides native co-simulation interfaces for MATLAB/Simulink, direct bridges to ROS/ROS2 for robotics, and streamlined data exchange with industry-standard CAE and CAD software.

Deployment & Visualization Ready: Prepare your validated models for the next stage. VDyna enables one-click export of assets and dynamics to major game engines like Unreal Engine and Unity for high-end visualization, immersive VR experiences, or hardware-in-the-loop (HIL) systems.

Modular & Configurable Modeling: Build systems iteratively using a component-based approach. Our modular architecture allows you to create libraries of verified subsystems—like powertrains, actuators, or sensor suites—and reconfigure them rapidly to explore design variations without rebuilding from scratch.

Built for Verification & Collaboration: Maintain confidence in your models with integrated version control support and a framework for building automated regression test suites. Share and compare simulation scenarios with team members to ensure consistency and traceability throughout the project lifecycle.