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class FlagCloth: public Scene
{
public:
FlagCloth(const char* name) : Scene(name) {}
void Initialize()
{
int dimx = 64;
int dimz = 32;
float radius = 0.05f;
float stretchStiffness = 0.9f;
float bendStiffness = 1.0f;
float shearStiffness = 0.9f;
int phase = NvFlexMakePhase(0, eNvFlexPhaseSelfCollide);
CreateSpringGrid(Vec3(0.0f, 0.0f, -3.0f), dimx, dimz, 1, radius, phase, stretchStiffness, bendStiffness, shearStiffness, 0.0f, 1.0f);
const int c1 = 0;
const int c2 = dimx*(dimz-1);
g_buffers->positions[c1].w = 0.0f;
g_buffers->positions[c2].w = 0.0f;
// add tethers
for (int i=0; i < int(g_buffers->positions.size()); ++i)
{
// hack to rotate cloth
swap(g_buffers->positions[i].y, g_buffers->positions[i].z);
g_buffers->positions[i].y *= -1.0f;
g_buffers->velocities[i] = RandomUnitVector()*0.1f;
float minSqrDist = FLT_MAX;
if (i != c1 && i != c2)
{
float stiffness = -0.8f;
float give = 0.1f;
float sqrDist = LengthSq(Vec3(g_buffers->positions[c1])-Vec3(g_buffers->positions[c2]));
if (sqrDist < minSqrDist)
{
CreateSpring(c1, i, stiffness, give);
CreateSpring(c2, i, stiffness, give);
minSqrDist = sqrDist;
}
}
}
g_params.radius = radius*1.0f;
g_params.dynamicFriction = 0.25f;
g_params.dissipation = 0.0f;
g_params.numIterations = 4;
g_params.drag = 0.06f;
g_params.relaxationFactor = 1.0f;
g_numSubsteps = 2;
// draw options
g_drawPoints = false;
g_drawSprings = false;
g_windFrequency *= 2.0f;
g_windStrength = 10.0f;
}
void Update()
{
const Vec3 kWindDir = Vec3(3.0f, 15.0f, 0.0f);
const float kNoise = fabsf(Perlin1D(g_windTime*0.05f, 2, 0.25f));
Vec3 wind = g_windStrength*kWindDir*Vec3(kNoise, kNoise*0.1f, -kNoise*0.1f);
g_params.wind[0] = wind.x;
g_params.wind[1] = wind.y;
g_params.wind[2] = wind.z;
}
};
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