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update sph sim

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This commit is contained in:
turanszkij
2018-05-08 12:33:08 +01:00
parent 2c59503ff9
commit c18dbdc4c2
3 changed files with 71 additions and 72 deletions
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WickedEngine/ShaderInterop_EmittedParticle.h
+1 -1
View File
@@ -44,7 +44,7 @@ CBUFFER(EmittedParticleCB, CBSLOT_OTHER_EMITTEDPARTICLE)
float xParticleMass;
float xParticleMotionBlurAmount;
float xEmitterOpacity;
float xPadding0_EmitterCB;
uint xEmitterMaxParticleCount;
float xSPH_h; // smoothing radius
float xSPH_h2; // smoothing radius ^ 2
WickedEngine/emittedparticle_nbodyCS.hlsl
+69 -71
View File
@@ -18,10 +18,8 @@ RWSTRUCTUREDBUFFER(counterBuffer, ParticleCounters, 4);
struct LDSParticle
{
float3 position;
float size;
float3 v; // velocity
float m; // mass
float p; // density
float3 v; // velocity
float P; // Pressure
};
groupshared LDSParticle LDSParticles[THREADCOUNT_SIMULATION];
@@ -31,23 +29,19 @@ void main( uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex, ui
{
uint aliveCount = counterBuffer[0].aliveCount;
uint particleIndex = aliveBuffer_CURRENT[DTid.x];
Particle particle = (Particle)0;
if (DTid.x < aliveCount)
{
uint particleIndexA = aliveBuffer_CURRENT[DTid.x];
Particle particleA = particleBuffer[particleIndexA];
float lifeLerpA = 1 - particleA.life / particleA.maxLife;
float particleSizeA = lerp(particleA.sizeBeginEnd.x, particleA.sizeBeginEnd.y, lifeLerpA);
LDSParticles[groupIndex].position = particleA.position;
LDSParticles[groupIndex].size = particleSizeA;
LDSParticles[groupIndex].v = particleA.velocity;
LDSParticles[groupIndex].m = xParticleMass;
LDSParticles[groupIndex].p = 0;
LDSParticles[groupIndex].P = 0;
particle = particleBuffer[particleIndex];
}
LDSParticles[groupIndex].position = particle.position;
LDSParticles[groupIndex].v = particle.velocity;
LDSParticles[groupIndex].p = 0;
LDSParticles[groupIndex].P = 0;
GroupMemoryBarrierWithGroupSync();
const uint LDSParticleCount = clamp(aliveCount - Gid.x * THREADCOUNT_SIMULATION, 0, THREADCOUNT_SIMULATION);
@@ -66,6 +60,7 @@ void main( uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex, ui
const float K = xSPH_K; // pressure constant
const float p0 = xSPH_p0; // reference density
const float e = xSPH_e; // viscosity constant
const float mass = xParticleMass;
// Compute density field:
@@ -82,14 +77,12 @@ void main( uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex, ui
float3 diff = particleA.position - particleB.position;
float r2 = dot(diff, diff); // distance squared
//float range = particleA.size + particleB.size; // range of affection
//float range2 = range * range; // range squared
if (r2 < h2)
{
float W = (315.0f / (64.0f * PI * h9)) * pow(h2 - r2, 3); // poly6 smoothing kernel
particleA.p += particleB.m * W;
//particleA.p += particleB.m * W;
particleA.p += mass * W; // constant mass
}
}
@@ -113,8 +106,8 @@ void main( uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex, ui
// Compute acceleration:
float3 a = 0; // pressure force
float3 av = 0; // viscosity force
float3 f_a = 0; // pressure force
float3 f_av = 0; // viscosity force
for (i = 0; i < LDSParticleCount; ++i)
{
@@ -127,90 +120,95 @@ void main( uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex, ui
float r2 = dot(diff, diff); // distance squared
float r = sqrt(r2);
//float range = particleA.size + particleB.size; // range of affection
if (r < h)
{
float3 rNorm = normalize(diff);
float W = (-45 / (PI * h6)) * pow(h - r, 2); // spiky kernel smoothing function
a += (particleB.m / particleA.m) * ((particleA.P + particleB.P) / (2 * particleA.p * particleB.p)) * W * rNorm;
//f_a += (particleB.m / particleA.m) * ((particleA.P + particleB.P) / (2 * particleA.p * particleB.p)) * W * rNorm;
f_a += mass * ((particleA.P + particleB.P) / (2 * particleA.p * particleB.p)) * W * rNorm; // constant mass
float r3 = r2 * r;
W = -(r3 / (2 * h3)) + (r2 / h2) + (h / (2 * r)) - 1;
av += (particleB.m / particleA.m) * (1.0f / particleB.p) * (particleB.v - particleA.v) * W * rNorm;
//f_av += (particleB.m / particleA.m) * (1.0f / particleB.p) * (particleB.v - particleA.v) * W * rNorm;
f_av += mass * (1.0f / particleB.p) * (particleB.v - particleA.v) * W * rNorm; // constant mass
}
}
}
a *= -1;
av *= e;
f_a *= -1;
f_av *= e;
// gravity:
const float3 G = float3(0, -9.8f, 0);
float3 gravity = G * particleA.p;
// apply all forces:
float3 force = a + av + gravity;
float3 force = (f_a + f_av) / particleA.p + G;
// integrate:
const float dt = g_xFrame_DeltaTime;
particleA.v += dt * force / particleA.p;
particleA.v += dt * force;
particleA.position += dt * particleA.v;
// drag:
particleA.v *= 0.98f;
float elastic = 0.9;
#ifdef FLOOR_COLLISION
// floor collision:
if (particleA.position.y - particleA.size < 0)
{
particleA.position.y = particleA.size;
particleA.v.y *= -elastic;
}
#endif // FLOOR_COLLISION
#ifdef BOX_COLLISION
// box collision:
float3 extent = float3(2, 0, 3);
if (particleA.position.x + particleA.size > extent.x)
{
particleA.position.x = extent.x - particleA.size;
particleA.v.x *= -elastic;
}
if (particleA.position.x - particleA.size < -extent.x)
{
particleA.position.x = -extent.x + particleA.size;
particleA.v.x *= -elastic;
}
if (particleA.position.z + particleA.size > extent.z)
{
particleA.position.z = extent.z - particleA.size;
particleA.v.z *= -elastic;
}
if (particleA.position.z - particleA.size < -extent.z)
{
particleA.position.z = -extent.z + particleA.size;
particleA.v.z *= -elastic;
}
#endif // BOX_COLLISION
if (DTid.x < aliveCount)
{
uint writeIndex = aliveBuffer_CURRENT[DTid.x];
particleBuffer[writeIndex].position = particleA.position;
particleBuffer[writeIndex].velocity = particleA.v;
float lifeLerp = 1 - particle.life / particle.maxLife;
float particleSize = lerp(particle.sizeBeginEnd.x, particle.sizeBeginEnd.y, lifeLerp);
float elastic = 0.6;
#ifdef FLOOR_COLLISION
// floor collision:
if (particleA.position.y - particleSize < 0)
{
particleA.position.y = particleSize;
particleA.v.y *= -elastic;
}
#endif // FLOOR_COLLISION
#ifdef BOX_COLLISION
// box collision:
float3 extent = float3(2, 0, 3);
if (particleA.position.x + particleSize > extent.x)
{
particleA.position.x = extent.x - particleSize;
particleA.v.x *= -elastic;
}
if (particleA.position.x - particleSize < -extent.x)
{
particleA.position.x = -extent.x + particleSize;
particleA.v.x *= -elastic;
}
if (particleA.position.z + particleSize > extent.z)
{
particleA.position.z = extent.z - particleSize;
particleA.v.z *= -elastic;
}
if (particleA.position.z - particleSize < -extent.z)
{
particleA.position.z = -extent.z + particleSize;
particleA.v.z *= -elastic;
}
#endif // BOX_COLLISION
particleBuffer[particleIndex].position = particleA.position;
particleBuffer[particleIndex].velocity = particleA.v;
#ifdef DEBUG_PRESSURE
// debug pressure:
particleBuffer[writeIndex].color_mirror = pressure_debug ? 0xFF : 0xFF00;
particleBuffer[particleIndex].color_mirror = pressure_debug ? 0xFF : 0xFF00;
#endif // DEBUG_PRESSURE
}
WickedEngine/wiEmittedParticle.cpp
+1
View File
@@ -309,6 +309,7 @@ void wiEmittedParticle::UpdateRenderData(GRAPHICSTHREAD threadID)
cb.xParticleColor = wiMath::CompressColor(XMFLOAT4(material->baseColor.x, material->baseColor.y, material->baseColor.z, 1));
cb.xEmitterOpacity = material->alpha;
cb.xParticleMass = mass;
cb.xEmitterMaxParticleCount = MAX_PARTICLES;
// SPH:
cb.xSPH_h = SPH_h;