MagicPhysX

.NET PhysX 5 binding to all platforms(win-x64, osx-x64, osx-arm64, linux-x64, linux-arm64) for 3D engine, deep learning, dedicated server of gaming. This library is built on top of NVIDIA PhysX 5 and physx-rs.

Use case:

3D View for MAUI, WPF, Avalonia
Physics for Your Own Game Engine
Simulate robotics for deep learning
Server side physics for dedicated server of gaming

Getting Started

PhysX Binding provides all of PhysX feature through C API. This library is distributed via NuGet.

PM> Install-Package MagicPhysX

C API is provided in NativeMethods in MagicPhysX namespace. Methods are almostly prefixed phys_Px or Px. In addition, extension methods are defined for contexts, just like object-oriented methods. For example, for PxPhysics*:

PxPhysics* physics = physx_create_physics(foundation);

// C API
PxScene* scene1 = PxPhysics_createScene_mut(physics, &sceneDesc);

// Extension methods
PxScene* scene2 = physics->CreateSceneMut(&sceneDesc);

Extension methods API is simpler and similar as original C++ PhysX API.

Here is the simple bound sphere on plane sample.

using MagicPhysX; // for enable Extension Methods.
using static MagicPhysX.NativeMethods; // recommend to use C API.

// create foundation(allocator, logging, etc...)
var foundation = physx_create_foundation();

// create physics system
var physics = physx_create_physics(foundation);

// create physics scene settings
var sceneDesc = PxSceneDesc_new(PxPhysics_getTolerancesScale(physics));

// you can create PhysX primitive(PxVec3, etc...) by C# struct
sceneDesc.gravity = new PxVec3 { x = 0.0f, y = -9.81f, z = 0.0f };

var dispatcher = phys_PxDefaultCpuDispatcherCreate(1, null, PxDefaultCpuDispatcherWaitForWorkMode.WaitForWork, 0);
sceneDesc.cpuDispatcher = (PxCpuDispatcher*)dispatcher;
sceneDesc.filterShader = get_default_simulation_filter_shader();

// create physics scene
var scene = physics->CreateSceneMut(&sceneDesc);

var material = physics->CreateMaterialMut(0.5f, 0.5f, 0.6f);

// create plane and add to scene
var plane = PxPlane_new_1(0.0f, 1.0f, 0.0f, 0.0f);
var groundPlane = physics->PhysPxCreatePlane(&plane, material);
scene->AddActorMut((PxActor*)groundPlane, null);

// create sphere and add to scene
var sphereGeo = PxSphereGeometry_new(10.0f);
var vec3 = new PxVec3 { x = 0.0f, y = 40.0f, z = 100.0f };
var transform = PxTransform_new_1(&vec3);
var identity = PxTransform_new_2(PxIDENTITY.PxIdentity);
var sphere = physics->PhysPxCreateDynamic(&transform, (PxGeometry*)&sphereGeo, material, 10.0f, &identity);
PxRigidBody_setAngularDamping_mut((PxRigidBody*)sphere, 0.5f);
scene->AddActorMut((PxActor*)sphere, null);

// simulate scene
for (int i = 0; i < 200; i++)
{
    // 30fps update
    scene->SimulateMut(1.0f / 30.0f, null, null, 0, true);
    uint error = 0;
    scene->FetchResultsMut(true, &error);

    // output to console(frame-count: position-y)
    var pose = PxRigidActor_getGlobalPose((PxRigidActor*)sphere);
    Console.WriteLine($"{i:000}: {pose.p.y}");
}

// release resources
PxScene_release_mut(scene);
PxDefaultCpuDispatcher_release_mut(dispatcher);
PxPhysics_release_mut(physics);

Other samples(FixedJoint, DistanceJoint, SphericalJoint, RevoluteJoint,RaycastSingle, BricksDoubleDomino, Geometries) are exist in ConsoleSandbox.

Document

MagicPhysX uses physx-rs C binding(physx-sys). You can refer these document.

PhysX Visual Debugger

MagicPhysX can enable PhysX Visual Debugger to debug physcs scene.

To use pvd, add this instruction on scene init.

var foundation = physx_create_foundation();

// create pvd
var pvd = phys_PxCreatePvd(foundation);

fixed (byte* bytePointer = "127.0.0.1"u8.ToArray())
{
    var transport = phys_PxDefaultPvdSocketTransportCreate(bytePointer, 5425, 10);
    pvd->ConnectMut(transport, PxPvdInstrumentationFlags.All);
}

// create physics
uint PX_PHYSICS_VERSION_MAJOR = 5;
uint PX_PHYSICS_VERSION_MINOR = 1;
uint PX_PHYSICS_VERSION_BUGFIX = 3;
uint versionNumber = (PX_PHYSICS_VERSION_MAJOR << 24) + (PX_PHYSICS_VERSION_MINOR << 16) + (PX_PHYSICS_VERSION_BUGFIX << 8);

var tolerancesScale = new PxTolerancesScale { length = 1, speed = 10 };
var physics = phys_PxCreatePhysics(versionNumber, foundation, &tolerancesScale, true, pvd, null);

phys_PxInitExtensions(physics, pvd);

var sceneDesc = PxSceneDesc_new(PxPhysics_getTolerancesScale(physics));
sceneDesc.gravity = new PxVec3 { x = 0.0f, y = -9.81f, z = 0.0f };

var dispatcher = phys_PxDefaultCpuDispatcherCreate(1, null, PxDefaultCpuDispatcherWaitForWorkMode.WaitForWork, 0);
sceneDesc.cpuDispatcher = (PxCpuDispatcher*)dispatcher;
sceneDesc.filterShader = get_default_simulation_filter_shader();

var scene = PxPhysics_createScene_mut(physics, &sceneDesc);

// pvd client
var pvdClient = scene->GetScenePvdClientMut();
if (pvdClient != null)
{
    pvdClient->SetScenePvdFlagMut(PxPvdSceneFlag.TransmitConstraints, true);
    pvdClient->SetScenePvdFlagMut(PxPvdSceneFlag.TransmitContacts, true);
    pvdClient->SetScenePvdFlagMut(PxPvdSceneFlag.TransmitScenequeries, true);
}

Toolkit Sample

C API is slightly complex in C# usage. Here is the sample of high level framework, PhysicsSystem.

using MagicPhysX.Toolkit;
using System.Numerics;

unsafe
{
    using var physics = new PhysicsSystem(enablePvd: false);
    using var scene = physics.CreateScene();

    var material = physics.CreateMaterial(0.5f, 0.5f, 0.6f);

    var plane = scene.AddStaticPlane(0.0f, 1.0f, 0.0f, 0.0f, new Vector3(0, 0, 0), Quaternion.Identity, material);
    var sphere = scene.AddDynamicSphere(1.0f, new Vector3(0.0f, 10.0f, 0.0f), Quaternion.Identity, 10.0f, material);

    for (var i = 0; i < 200; i++)
    {
        scene.Update(1.0f / 30.0f);

        var position = sphere.transform.position;
        Console.WriteLine($"{i:D2} : x={position.X:F6}, y={position.Y:F6}, z={position.Z:F6}");
    }
}

Code sample is available in MagicPhysX.Toolkit.

Native Build Instruction

require Rust.

Open directory src\libmagicphysx. Run cargo build.

Native binaries in package is built on GitHub Actions build-physx.yml. If we need to update physx-sys(PhysX) version, run this GitHub Actions to input physxversion.

License

This library is licensed under the MIT License.

Cysharp / MagicPhysX