void ExampleExperimentFields::DrawScalarField()
{
viewer->clear();
//Load scalar field
ScalarField2 field;
if (!field.load(ScalarfieldFilename))
{
output << "Error loading field file " << ScalarfieldFilename << "\n";
return;
}
//Get the minimum/maximum value in that field
float32 min = std::numeric_limits<float32>::max();
float32 max = -std::numeric_limits<float32>::max();
for(size_t j=0; j<field.dims()[1]; j++)
{
for(size_t i=0; i< field.dims()[0]; i++)
{
const float32 val = field.nodeScalar(i,j);
min = val < min ? val : min;
max = val > max ? val : max;
}
}
//Draw a point for each grid vertex.
for(size_t j=0; j<field.dims()[1]; j++)
{
for(size_t i=0; i<field.dims()[0]; i++)
{
const float32 val = field.nodeScalar(i, j);
const float32 c = (val - min) / (max - min);
Point2D p;
p.position = field.nodePosition(i, j);
p.size = 5;
//Use a grayscale depending on the actual value
p.color[0] = c; p.color[1] = c; p.color[2] = c;
viewer->addPoint(p);
}
}
viewer->refresh();
}
void IterativeLevelSetSolver2::extrapolate(
const FaceCenteredGrid2& input,
const ScalarField2& sdf,
double maxDistance,
FaceCenteredGrid2* output) {
JET_THROW_INVALID_ARG_IF(!input.hasSameShape(*output));
const Vector2D gridSpacing = input.gridSpacing();
auto u = input.uConstAccessor();
auto uPos = input.uPosition();
Array2<double> sdfAtU(u.size());
input.parallelForEachUIndex([&](size_t i, size_t j) {
sdfAtU(i, j) = sdf.sample(uPos(i, j));
});
extrapolate(
u,
sdfAtU,
gridSpacing,
maxDistance,
output->uAccessor());
auto v = input.vConstAccessor();
auto vPos = input.vPosition();
Array2<double> sdfAtV(v.size());
input.parallelForEachVIndex([&](size_t i, size_t j) {
sdfAtV(i, j) = sdf.sample(vPos(i, j));
});
extrapolate(
v,
sdfAtV,
gridSpacing,
maxDistance,
output->vAccessor());
}
void IterativeLevelSetSolver2::extrapolate(
const CollocatedVectorGrid2& input,
const ScalarField2& sdf,
double maxDistance,
CollocatedVectorGrid2* output) {
JET_THROW_INVALID_ARG_IF(!input.hasSameShape(*output));
Array2<double> sdfGrid(input.dataSize());
auto pos = input.dataPosition();
sdfGrid.parallelForEachIndex([&](size_t i, size_t j) {
sdfGrid(i, j) = sdf.sample(pos(i, j));
});
const Vector2D gridSpacing = input.gridSpacing();
Array2<double> u(input.dataSize());
Array2<double> u0(input.dataSize());
Array2<double> v(input.dataSize());
Array2<double> v0(input.dataSize());
input.parallelForEachDataPointIndex([&](size_t i, size_t j) {
u(i, j) = input(i, j).x;
v(i, j) = input(i, j).y;
});
extrapolate(
u,
sdfGrid.constAccessor(),
gridSpacing,
maxDistance,
u0);
extrapolate(
v,
sdfGrid.constAccessor(),
gridSpacing,
maxDistance,
v0);
output->parallelForEachDataPointIndex([&](size_t i, size_t j) {
(*output)(i, j).x = u(i, j);
(*output)(i, j).y = v(i, j);
});
}
void IterativeLevelSetSolver2::extrapolate(
const ScalarGrid2& input,
const ScalarField2& sdf,
double maxDistance,
ScalarGrid2* output) {
JET_THROW_INVALID_ARG_IF(!input.hasSameShape(*output));
Array2<double> sdfGrid(input.dataSize());
auto pos = input.dataPosition();
sdfGrid.parallelForEachIndex([&](size_t i, size_t j) {
sdfGrid(i, j) = sdf.sample(pos(i, j));
});
extrapolate(
input.constDataAccessor(),
sdfGrid.constAccessor(),
input.gridSpacing(),
maxDistance,
output->dataAccessor());
}
void Experiment3_1::DrawRegularMesh()
{
viewer->clear();
//Load scalar field
ScalarField2 field;
if (!field.load(scalar_filename))
{
output << "Error loading field file " << scalar_filename << "\n";
return;
}
//Get the minimum/maximum value in that field
float32 min = std::numeric_limits<float32>::max();
float32 max = -std::numeric_limits<float32>::max();
for(size_t j=0; j<field.dims()[1]; j++)
{
for(size_t i=0; i< field.dims()[0]; i++)
{
const float32 val = field.nodeScalar(i,j);
min = val < min ? val : min;
max = val > max ? val : max;
}
}
//Plot the grid
//Traverse one dimension first and then the other dimension
for(size_t j=0; j<field.dims()[1]; j++)
{
viewer->addLine(field.nodePosition(0,j), field.nodePosition(field.dims()[0]-1,j), makeVector4f(0.5,0.5,0.5,grid_alpha), 1);
}
for(size_t i=0; i<field.dims()[0]; i++)
{
viewer->addLine(field.nodePosition(i,0), field.nodePosition(i,field.dims()[1]-1), makeVector4f(0.5,0.5,0.5,grid_alpha), 1);
}
//Optionally overlay data on the grid
if (grid_w_data == true )
{
//Draw a point for each grid vertex.
for(size_t j=0; j<field.dims()[1]; j++)
{
for(size_t i=0; i<field.dims()[0]; i++)
{
const float32 val = field.nodeScalar(i, j);
const float32 c = (val - min) / (max - min);
Point2D p;
p.position = field.nodePosition(i, j);
p.size = 5;
//Use a grayscale depending on the actual value
p.color[0] = c; p.color[1] = c; p.color[2] = c;
viewer->addPoint(p);
}
}
}
viewer->refresh();
}
void Experiment3_1::DrawIsoContour_Asymp()
{
viewer->clear();
//Load scalar field
ScalarField2 field;
if (!field.load(scalar_filename))
{
output << "Error loading field file " << scalar_filename << "\n";
return;
}
//Get the minimum/maximum value in that field
float32 min = std::numeric_limits<float32>::max();
float32 max = -std::numeric_limits<float32>::max();
for(size_t j=0; j<field.dims()[1]; j++)
{
for(size_t i=0; i< field.dims()[0]; i++)
{
const float32 val = field.nodeScalar(i,j);
min = val < min ? val : min;
max = val > max ? val : max;
}
}
//Plot the grid
//Traverse one dimension first and then the other dimension
for(size_t j=0; j<field.dims()[1]; j++)
{
viewer->addLine(field.nodePosition(0,j), field.nodePosition(field.dims()[0]-1,j), makeVector4f(0.5,0.5,0.5,grid_alpha), 1);
}
for(size_t i=0; i<field.dims()[0]; i++)
{
viewer->addLine(field.nodePosition(i,0), field.nodePosition(i,field.dims()[1]-1), makeVector4f(0.5,0.5,0.5,grid_alpha), 1);
}
//Optionally overlay data on the grid
if (grid_w_data == true )
{
//Draw a point for each grid vertex.
for(size_t j=0; j<field.dims()[1]; j++)
{
for(size_t i=0; i<field.dims()[0]; i++)
{
const float32 val = field.nodeScalar(i, j);
const float32 c = (val - min) / (max - min);
Point2D p;
p.position = field.nodePosition(i, j);
p.size = 5;
//Use a grayscale depending on the actual value
p.color[0] = c; p.color[1] = c; p.color[2] = c;
viewer->addPoint(p);
}
}
}
viewer->refresh();
//Plot the Iso Contour
//Traverse the cells
for(size_t i=0; i<field.dims()[0]-1; i++)
{
for(size_t j=0; j<field.dims()[1]-1; j++)
{
//Compute Max and Min values in each cell
float32 fval[4];
fval[0]= field.nodeScalar(i,j);
fval[1]= field.nodeScalar(i,j+1);
fval[2]= field.nodeScalar(i+1,j+1);
fval[3]= field.nodeScalar(i+1,j);
vector <Vector2f> Pos;
Pos.resize(4);
Pos[0]=field.nodePosition(i,j);
Pos[1]=field.nodePosition(i,j+1);
Pos[2]=field.nodePosition(i+1,j+1);
Pos[3]=field.nodePosition(i+1,j);
//output << "** "<< Pos[0][0] << " " << Pos[0][1] <<"\n";
//output << field.nodePosition(i,j)[0] << " "<< field.nodePosition(i,j)[1] << "\n" ;
float32 maxf, minf;
maxf=fmax(fval[0],fval[1]);
maxf=fmax(maxf,fval[2]);
maxf=fmax(maxf,fval[3]);
minf=fmin(fval[0],fval[1]);
minf=fmin(minf,fval[2]);
minf=fmin(minf,fval[3]);
//Check if the iso contour passes the grid
if((iso_c < minf) || (iso_c > maxf))
continue;
else //We plot the iso contour
{
float32 EdgeChar[3][4];
//Now figure out the signs for the four nodes
bool sign[4]= {0,0,0,0};
for(int k=0; k<4; k++)
{
if(fval[k]>=iso_c)
sign[k] = 1;
}
//Traverse the nodes clockwise and see if the edge carries a crossing point
for(int k=0; k<4; k++)
{
if( sign[k] ^ sign[(k+1)%4] )
{
EdgeChar[2][k] = 1;
float32 x,y;
x = ( (Pos[(k+1)%4][0] - Pos[k][0])*iso_c + Pos[k][0] * fval[(k+1)%4] - Pos[(k+1)%4][0] * fval[k] ) / ( fval[(k+1)%4] - fval[k] ) ;
y = ( (Pos[(k+1)%4][1] - Pos[k][1])*iso_c + Pos[k][1] * fval[(k+1)%4] - Pos[(k+1)%4][1] * fval[k] ) / ( fval[(k+1)%4] - fval[k] ) ;
EdgeChar[0][k] = x;
EdgeChar[1][k] = y;
}
else
EdgeChar[2][k] = 0;
}
//Count the number of edges that have a valid crossing point. It should be either 2 or 4
int EdgeCount=0;
for(int k=0; k<4; k++)
{
if(EdgeChar[2][k]==1)
EdgeCount++;
}
if(EdgeCount == 2)
{
//Simply plot the contour
vector <Vector2f> LineEnd;
LineEnd.clear();
LineEnd.resize(2);
int index=0;
for(int k=0; k<4; k++)
{
if(EdgeChar[2][k]==1)
{
LineEnd[index]= makeVector2f(EdgeChar[0][k], EdgeChar[1][k]) ;
index++;
}
}
viewer->addLine(LineEnd[0], LineEnd[1], makeVector4f(0.5,0.5,0.5,iso_alpha), 2);
viewer->refresh();
}
else //Cell has the contour intersecting at 4 points
{
//There is an ambiguity to be resolved
float32 fmid= (fval[3]*fval[1] - fval[2]*fval[0]) / ( fval[3]+fval[1] -fval[2] - fval[0] ) ;
vector <Vector2f> LineEnd;
LineEnd.clear();
LineEnd.resize(4);
for(int k=0; k<4; k++)
{
LineEnd[k]= makeVector2f(EdgeChar[0][k], EdgeChar[1][k]) ;
}
if(fval[1] < iso_c)
{
if(iso_c > fmid) //Connect 3 to 0 and 1 to 2
{
viewer->addLine(LineEnd[3], LineEnd[0], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->addLine(LineEnd[1], LineEnd[2], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->refresh();
}
else //Connect 0 to 1 and 2 to 3
{
viewer->addLine(LineEnd[0], LineEnd[1], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->addLine(LineEnd[2], LineEnd[3], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->refresh();
}
}
else
{
if(iso_c > fmid) //Connect 0 to 1 and 2 to 3
{
viewer->addLine(LineEnd[0], LineEnd[1], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->addLine(LineEnd[2], LineEnd[3], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->refresh();
}
else //Connect 3 to 0 and 1 to 2
{
viewer->addLine(LineEnd[3], LineEnd[0], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->addLine(LineEnd[1], LineEnd[2], makeVector4f(1,0.5,0.5,iso_alpha), 2);
viewer->refresh();
}
}
}
}
}
}
}
void ExampleExperimentFields::DrawTexture()
{
viewer->clear();
//Load the texture using Qt
QImage image(ImageFilename.c_str());
//Get its (original) dimensions. Used as bounds later.
const float fWidth = (float)image.width();
const float fHeight = (float)image.height();
//Resize to power-of-two and mirror.
image = image.mirrored().scaled(NextPOT(image.width()), NextPOT(image.height()));
//Get its new integer dimensions.
const int iWidth = image.width();
const int iHeight = image.height();
if (bColoredTexture)
{
//Create three color channels for the texture
//Each of them is represented using a scalar field
ScalarField2 Red;
Red.init(makeVector2f(-fWidth, -fHeight), makeVector2f(fWidth, fHeight), makeVector2ui(iWidth, iHeight));
ScalarField2 Green;
Green.init(makeVector2f(-fWidth, -fHeight), makeVector2f(fWidth, fHeight), makeVector2ui(iWidth, iHeight));
ScalarField2 Blue;
Blue.init(makeVector2f(-fWidth, -fHeight), makeVector2f(fWidth, fHeight), makeVector2ui(iWidth, iHeight));
//Fill the scalar fields
for(size_t j=0; j<Red.dims()[1]; j++)
{
for(size_t i=0; i<Red.dims()[0]; i++)
{
Red.setNodeScalar(i, j, (float)(qRed(image.pixel(i, j))) / 255.0 );
Green.setNodeScalar(i, j, (float)(qGreen(image.pixel(i, j))) / 255.0 );
Blue.setNodeScalar(i, j, (float)(qBlue(image.pixel(i, j))) / 255.0 );
}
}
//Set the texture in the viewer
viewer->setTextureRGB(Red.getData(), Green.getData(), Blue.getData());
}
else
{
//Create one gray color channel represented as a scalar field
ScalarField2 Gray;
Gray.init(makeVector2f(-fWidth, -fHeight), makeVector2f(fWidth, fHeight), makeVector2ui(iWidth, iHeight));
//Set the values at the vertices
for(size_t j=0; j<Gray.dims()[1]; j++)
{
for(size_t i=0; i<Gray.dims()[0]; i++)
{
Gray.setNodeScalar(i, j, (float)(qGray(image.pixel(i, j))) / 255.0 );
}
}
//Set the texture in the viewer
viewer->setTextureGray(Gray.getData());
}
viewer->refresh();
}
void GridFractionalSinglePhasePressureSolver2::buildWeights(
const FaceCenteredGrid2& input, const ScalarField2& boundarySdf,
const VectorField2& boundaryVelocity, const ScalarField2& fluidSdf) {
auto size = input.resolution();
// Build levels
size_t maxLevels = 1;
if (_mgSystemSolver != nullptr) {
maxLevels = _mgSystemSolver->params().maxNumberOfLevels;
}
FdmMgUtils2::resizeArrayWithFinest(size, maxLevels, &_fluidSdf);
_uWeights.resize(_fluidSdf.size());
_vWeights.resize(_fluidSdf.size());
for (size_t l = 0; l < _fluidSdf.size(); ++l) {
_uWeights[l].resize(_fluidSdf[l].size() + Size2(1, 0));
_vWeights[l].resize(_fluidSdf[l].size() + Size2(0, 1));
}
// Build top-level grids
auto cellPos = input.cellCenterPosition();
auto uPos = input.uPosition();
auto vPos = input.vPosition();
_boundaryVel = boundaryVelocity.sampler();
Vector2D h = input.gridSpacing();
_fluidSdf[0].parallelForEachIndex([&](size_t i, size_t j) {
_fluidSdf[0](i, j) = static_cast<float>(fluidSdf.sample(cellPos(i, j)));
});
_uWeights[0].parallelForEachIndex([&](size_t i, size_t j) {
Vector2D pt = uPos(i, j);
double phi0 = boundarySdf.sample(pt - Vector2D(0.5 * h.x, 0.0));
double phi1 = boundarySdf.sample(pt + Vector2D(0.5 * h.x, 0.0));
double frac = fractionInsideSdf(phi0, phi1);
double weight = clamp(1.0 - frac, 0.0, 1.0);
// Clamp non-zero weight to kMinWeight. Having nearly-zero element
// in the matrix can be an issue.
if (weight < kMinWeight && weight > 0.0) {
weight = kMinWeight;
}
_uWeights[0](i, j) = static_cast<float>(weight);
});
_vWeights[0].parallelForEachIndex([&](size_t i, size_t j) {
Vector2D pt = vPos(i, j);
double phi0 = boundarySdf.sample(pt - Vector2D(0.0, 0.5 * h.y));
double phi1 = boundarySdf.sample(pt + Vector2D(0.0, 0.5 * h.y));
double frac = fractionInsideSdf(phi0, phi1);
double weight = clamp(1.0 - frac, 0.0, 1.0);
// Clamp non-zero weight to kMinWeight. Having nearly-zero element
// in the matrix can be an issue.
if (weight < kMinWeight && weight > 0.0) {
weight = kMinWeight;
}
_vWeights[0](i, j) = static_cast<float>(weight);
});
// Build sub-levels
for (size_t l = 1; l < _fluidSdf.size(); ++l) {
const auto& finerFluidSdf = _fluidSdf[l - 1];
auto& coarserFluidSdf = _fluidSdf[l];
const auto& finerUWeight = _uWeights[l - 1];
auto& coarserUWeight = _uWeights[l];
const auto& finerVWeight = _vWeights[l - 1];
auto& coarserVWeight = _vWeights[l];
// Fluid SDF
restrict(finerFluidSdf, &coarserFluidSdf);
restrict(finerUWeight, &coarserUWeight);
restrict(finerVWeight, &coarserVWeight);
}
}
