NxFluid* CreateFluid(const NxVec3& pos, NxU32 sideNum, NxReal distance, NxScene* scene)
{
// Create a set of particles
gParticleBufferNum = 0;
NxReal rad = sideNum*distance*0.5f;
for (NxU32 i = 0; i < sideNum; i++)
{
for (NxU32 j = 0; j < sideNum; j++)
{
for (NxU32 k = 0; k < sideNum; k++)
{
NxVec3 p = NxVec3(i*distance, j*distance, k*distance);
if (p.distance(NxVec3(rad, rad, rad)) < rad)
{
p += pos - NxVec3(rad, rad, rad);
gParticleBuffer[gParticleBufferNum++] = p;
}
}
}
}
// 先需要初始化大量粒子的参数
// Set structure to pass particles, and receive them after every simulation step
NxParticleData particles;
//particles.maxParticles = gParticleBufferCap;
particles.numParticlesPtr = &gParticleBufferNum;
particles.bufferPos = &gParticleBuffer[0].x;
particles.bufferPosByteStride = sizeof(NxVec3);
// 然后初始化流体的各项参数
// Create a fluid descriptor
NxFluidDesc fluidDesc;
fluidDesc.maxParticles = gParticleBufferCap;
fluidDesc.kernelRadiusMultiplier = KERNEL_RADIUS_MULTIPLIER;
fluidDesc.restParticlesPerMeter = REST_PARTICLES_PER_METER;
fluidDesc.motionLimitMultiplier = MOTION_LIMIT_MULTIPLIER;
fluidDesc.packetSizeMultiplier = PACKET_SIZE_MULTIPLIER;
fluidDesc.stiffness = 50;
fluidDesc.viscosity = 22;
fluidDesc.restDensity = 1000;
fluidDesc.damping = 0;
fluidDesc.restitutionForStaticShapes = 0.4;
fluidDesc.dynamicFrictionForStaticShapes = 0.3;
fluidDesc.collisionResponseCoefficient = 0.5f;
fluidDesc.collisionDistanceMultiplier = 0.1f;
fluidDesc.simulationMethod = NX_F_SPH; //NX_F_NO_PARTICLE_INTERACTION;
// 将流体需要的粒子与上述初始化的粒子关联起来
fluidDesc.initialParticleData = particles;
fluidDesc.particlesWriteData = particles;
fluidDesc.flags &= ~NX_FF_HARDWARE;
fluidDesc.flags |= NX_FF_COLLISION_TWOWAY;
NxFluid* fl = gScene->createFluid(fluidDesc);
assert(fl != NULL);
return fl;
}
NxFluid* CreateFluid(const NxVec3& pos, NxU32 sideNum, NxReal distance, NxScene* scene)
{
float rad = sideNum*distance*0.5;
for (unsigned i=0; i<sideNum; i++)
for (unsigned j=0; j<sideNum; j++)
for (unsigned k=0; k<sideNum; k++)
{
NxVec3 p = NxVec3(i*distance,j*distance,k*distance);
if (p.distance(NxVec3(rad,rad,rad)) < rad)
{
p += pos;
if(gParticleBufferNum< MAX_PARTICLES)
gParticleBuffer[gParticleBufferNum++] = p;
}
}
NxParticleData particles;
//particles.maxParticles = gParticleBufferCap;
particles.numParticlesPtr = &gParticleBufferNum;
particles.bufferPos = &gParticleBuffer[0].x;
particles.bufferPosByteStride = sizeof(NxVec3);
//Create a fluid descriptor
NxFluidDesc fluidDesc;
fluidDesc.maxParticles = MAX_PARTICLES;
fluidDesc.flags |= NX_FF_COLLISION_TWOWAY;
fluidDesc.simulationMethod = NX_F_SPH;
fluidDesc.restParticlesPerMeter = 5.0f;
fluidDesc.motionLimitMultiplier = 10.0f;
fluidDesc.restDensity = 1000.0f;
fluidDesc.kernelRadiusMultiplier = 1.6f;
fluidDesc.stiffness = 10.0f;
fluidDesc.viscosity = 50.0f;
fluidDesc.damping = 0.5f;
fluidDesc.packetSizeMultiplier = 16;
fluidDesc.name = "fluid";
fluidDesc.kernelRadiusMultiplier = KERNEL_RADIUS_MULTIPLIER;
fluidDesc.restParticlesPerMeter = REST_PARTICLES_PER_METER;
fluidDesc.motionLimitMultiplier = MOTION_LIMIT_MULTIPLIER;
fluidDesc.packetSizeMultiplier = PACKET_SIZE_MULTIPLIER;
fluidDesc.stiffness = 40; // 50
fluidDesc.viscosity = 22;
fluidDesc.restDensity = 1000;
fluidDesc.damping = 0;
// There are some API changes since 280 version, Fluid collision coefficients have been renamed,
// E.g. NxFluidDesc::dynamicCollisionAdhesion is named NxFluidDesc::dynamicFrictionForDynamicShapes.
#if NX_SDK_VERSION_NUMBER < 280
fluidDesc.staticCollisionRestitution = 0.162f;
fluidDesc.staticCollisionAdhesion = 0.146f;
fluidDesc.dynamicCollisionRestitution = 0.5f;
fluidDesc.dynamicCollisionAdhesion = 0.5f;
#else
fluidDesc.restitutionForStaticShapes = 0.162f;
fluidDesc.dynamicFrictionForStaticShapes = 0.146f;
fluidDesc.restitutionForDynamicShapes = 0.5f;
fluidDesc.dynamicFrictionForDynamicShapes = 0.5f;
#endif
fluidDesc.simulationMethod = NX_F_SPH; //NX_F_NO_PARTICLE_INTERACTION;
fluidDesc.initialParticleData = particles;
fluidDesc.particlesWriteData = particles;
if(!bHardwareFluid)
fluidDesc.flags &= ~NX_FF_HARDWARE;
fluid = gScene->createFluid(fluidDesc);
if(!fluid)
{
fluidDesc.flags &= ~NX_FF_HARDWARE;
bHardwareFluid = false;
fluid = gScene->createFluid(fluidDesc);
}
assert(fluid != NULL);
return fluid;
}
void SampleCollision::setup()
{
SetTitleString(getName());
#ifdef __PPCGEKKO__
SetHelpString(" a: create rigid bodies");
#else
SetHelpString(" b: create rigid bodies");
#endif
gShadows = false;
// Create objects in the scene
if (!InitCooking(gAllocator, &gErrorStream))
{
printf("\nError: Unable to initialize the cooking library, exiting the sample.\n\n");
return;
}
// Load ASE file
CookASE("fluidSample.ase", gScene, NxVec3(1,10,0));
CookASE("coolFlow.ase", gScene, NxVec3(1,6,-0), NxVec3(1,0.2,1));
CloseCooking();
// Add a box shaped drain.
NxActorDesc boxDrainActor;
NxBoxShapeDesc boxDrainShape;
boxDrainActor.shapes.pushBack(&boxDrainShape);
boxDrainShape.dimensions.set(40,1,40);
boxDrainShape.shapeFlags |= NX_SF_FLUID_DRAIN;
boxDrainActor.globalPose.t.set(0, 0, 0);
gScene->createActor(boxDrainActor);
//Pre cook hotspots
NxBounds3 precookAABB;
precookAABB.set(NxVec3(-20,-20,-20), NxVec3(20,20,20));
// gScene->cookFluidMeshHotspot(precookAABB, PACKET_SIZE_MULTIPLIER, REST_PARTICLES_PER_METER, KERNEL_RADIUS_MULTIPLIER, MOTION_LIMIT_MULTIPLIER, COLLISION_DISTANCE_MULTIPLIER );
//Create a set of initial particles
ParticleSDK* initParticles = new ParticleSDK[MAX_PARTICLES];
unsigned initParticlesNum = 0;
NxVec3 fluidPos(0, 11.6, 0);
float distance = 0.1f;
unsigned sideNum = 16;
float rad = sideNum*distance*0.5f;
for (unsigned i=0; i<sideNum; i++)
for (unsigned j=0; j<sideNum; j++)
for (unsigned k=0; k<sideNum; k++)
{
NxVec3 p = NxVec3(i*distance,j*distance,k*distance);
if (p.distance(NxVec3(rad,rad,rad)) < rad)
{
p += fluidPos;
ParticleSDK& newParticle = initParticles[initParticlesNum++];
newParticle.position = p;
newParticle.velocity = NxVec3(0,0,0);
}
}
//Setup structure to pass initial particles.
NxParticleData initParticleData;
initParticleData.numParticlesPtr = &initParticlesNum;
initParticleData.bufferPos = &initParticles[0].position.x;
initParticleData.bufferPosByteStride = sizeof(ParticleSDK);
initParticleData.bufferVel = &initParticles[0].velocity.x;
initParticleData.bufferVelByteStride = sizeof(ParticleSDK);
//Setup fluid descriptor
NxFluidDesc fluidDesc;
fluidDesc.maxParticles = initParticlesNum;
fluidDesc.kernelRadiusMultiplier = KERNEL_RADIUS_MULTIPLIER;
fluidDesc.restParticlesPerMeter = REST_PARTICLES_PER_METER;
fluidDesc.collisionDistanceMultiplier = COLLISION_DISTANCE_MULTIPLIER;
fluidDesc.stiffness = 50.0f;
fluidDesc.viscosity = 22.0f;
fluidDesc.damping = 0.0f;
fluidDesc.restitutionForStaticShapes = 0.4f;
fluidDesc.dynamicFrictionForStaticShapes = 0.03f;
fluidDesc.simulationMethod = NX_F_SPH; //NX_F_NO_PARTICLE_INTERACTION;
if (!gHardwareSimulation)
fluidDesc.flags &= ~NX_FF_HARDWARE;
fluidDesc.initialParticleData = initParticleData;
//Create user fluid.
//- create NxFluid in NxScene
//- setup the buffers to read from data from the SDK
//- set NxFluid::userData field to MyFluid instance
bool trackUserData = false;
bool provideCollisionNormals = false;
MyFluid* fluid = new MyFluid(gScene, fluidDesc, trackUserData, provideCollisionNormals, NxVec3(0.2f,0.3f,0.7f), 0.03f);
assert(fluid);
gMyFluids.pushBack(fluid);
delete[] initParticles;
gCameraPos.set(23, 14, 23);
gCameraForward = fluidPos - NxVec3(0, 3, 0) - gCameraPos;
gCameraForward.normalize();
}