void
simpleFluidEmitter::omniFluidEmitter(
MFnFluid& fluid,
const MMatrix& fluidWorldMatrix,
int plugIndex,
MDataBlock& block,
double dt,
double conversion,
double dropoff
)
//==============================================================================
//
// Method:
//
// simpleFluidEmitter::omniFluidEmitter
//
// Description:
//
// Emits fluid from a point, or from a set of object control points.
//
// Parameters:
//
// fluid: fluid into which we are emitting
// fluidWorldMatrix: object->world matrix for the fluid
// plugIndex: identifies which fluid connected to the emitter
// we are emitting into
// block: datablock for the emitter, to retrieve attribute
// values
// dt: time delta for this frame
// conversion: mapping from UI emission rates to internal units
// dropoff: specifies how much emission rate drops off as
// we move away from each emission point.
//
// Notes:
//
// If no owner object is present for the emitter, we simply emit from
// the emitter position. If an owner object is present, then we emit
// from each control point of that object in an identical fashion.
//
// To associate an owner object with an emitter, use the
// addDynamic MEL command, e.g. "addDynamic simpleFluidEmitter1 pPlane1".
//
//==============================================================================
{
// find the positions that we need to emit from
//
MVectorArray emitterPositions;
// first, try to get them from an owner object, which will have its
// "ownerPositionData" attribute feeding into the emitter. These
// values are in worldspace
//
bool gotOwnerPositions = false;
MObject ownerShape = getOwnerShape();
if( ownerShape != MObject::kNullObj )
{
MStatus status;
MDataHandle hOwnerPos = block.inputValue( mOwnerPosData, &status );
if( status == MS::kSuccess )
{
MObject dOwnerPos = hOwnerPos.data();
MFnVectorArrayData fnOwnerPos( dOwnerPos );
MVectorArray posArray = fnOwnerPos.array( &status );
if( status == MS::kSuccess )
{
// assign vectors from block to ownerPosArray.
//
for( unsigned int i = 0; i < posArray.length(); i ++ )
{
emitterPositions.append( posArray[i] );
}
gotOwnerPositions = true;
}
}
}
// there was no owner object, so we just use the emitter position for
// emission.
//
if( !gotOwnerPositions )
{
MPoint emitterPos = getWorldPosition();
emitterPositions.append( emitterPos );
}
// get emission rates for density, fuel, heat, and emission color
//
double densityEmit = fluidDensityEmission( block );
double fuelEmit = fluidFuelEmission( block );
double heatEmit = fluidHeatEmission( block );
bool doEmitColor = fluidEmitColor( block );
MColor emitColor = fluidColor( block );
// rate modulation based on frame time, user value conversion factor, and
// standard emitter "rate" value (not actually exposed in most fluid
// emitters, but there anyway).
//
double theRate = getRate(block) * dt * conversion;
// get voxel dimensions and sizes (object space)
//
double size[3];
unsigned int res[3];
fluid.getDimensions( size[0], size[1], size[2] );
fluid.getResolution( res[0], res[1], res[2] );
// voxel sizes
double dx = size[0] / res[0];
double dy = size[1] / res[1];
double dz = size[2] / res[2];
// voxel centers
double Ox = -size[0]/2;
double Oy = -size[1]/2;
double Oz = -size[2]/2;
// emission will only happen for voxels whose centers lie within
// "minDist" and "maxDist" of an emitter position
//
double minDist = getMinDistance( block );
double maxDist = getMaxDistance( block );
// bump up the min/max distance values so that they
// are both > 0, and there is at least about a half
// voxel between the min and max values, to prevent aliasing
// artifacts caused by emitters missing most voxel centers
//
MTransformationMatrix fluidXform( fluidWorldMatrix );
double fluidScale[3];
fluidXform.getScale( fluidScale, MSpace::kWorld );
// compute smallest voxel diagonal length
double wsX = fabs(fluidScale[0]*dx);
double wsY = fabs(fluidScale[1]*dy);
double wsZ = fabs(fluidScale[2]*dz);
double wsMin = MIN( MIN( wsX, wsY), wsZ );
double wsMax = MAX( MAX( wsX, wsY), wsZ );
double wsDiag = wsMin * sqrt(3.0);
// make sure emission range is bigger than 0.5 voxels
if ( maxDist <= minDist || maxDist <= (wsDiag/2.0) ) {
if ( minDist < 0 ) minDist = 0;
maxDist = minDist + wsDiag/2.0;
dropoff = 0;
}
// Now, it's time to actually emit into the fluid:
//
// foreach emitter point
// foreach voxel
// - select some points in the voxel
// - compute a dropoff function from the emitter point
// - emit an appropriate amount of fluid into the voxel
//
// Since we've already expanded the min/max distances to cover
// the smallest voxel dimension, we should only need 1 sample per
// voxel, unless the voxels are highly non-square. We increase the
// number of samples in these cases.
//
// If the "jitter" flag is enabled, we jitter each sample position,
// using the rangen() function, which keeps track of independent
// random states for each fluid, to make sure that results are
// repeatable for multiple simulation runs.
//
// basic sample count
int numSamples = 1;
// increase samples if necessary for non-square voxels
if(wsMin >.00001)
{
numSamples = (int)(wsMax/wsMin + .5);
if(numSamples > 8)
numSamples = 8;
if(numSamples < 1)
numSamples = 1;
}
bool jitter = fluidJitter(block);
if( !jitter )
{
// I don't have a good uniform sample generator for an
// arbitrary number of samples. It would be a good idea to use
// one here. For now, just use 1 sample for the non-jittered case.
//
numSamples = 1;
}
for( unsigned int p = 0; p < emitterPositions.length(); p++ )
{
MPoint emitterWorldPos = emitterPositions[p];
// loop through all voxels, looking for ones that lie at least
// partially within the dropoff field around this emitter point
//
for( unsigned int i = 0; i < res[0]; i++ )
{
double x = Ox + i*dx;
for( unsigned int j = 0; j < res[1]; j++ )
{
double y = Oy + j*dy;
for( unsigned int k = 0; k < res[2]; k++ )
{
double z = Oz + k*dz;
int si;
for( si = 0; si < numSamples; si++ )
{
// compute sample point (fluid object space)
//
double rx, ry, rz;
if( jitter )
{
rx = x + randgen()*dx;
ry = y + randgen()*dy;
rz = z + randgen()*dz;
}
else
{
rx = x + 0.5*dx;
ry = y + 0.5*dy;
rz = z + 0.5*dz;
}
// compute distance from sample to emitter point
//
MPoint point( rx, ry, rz );
point *= fluidWorldMatrix;
MVector diff = point - emitterWorldPos;
double distSquared = diff * diff;
double dist = diff.length();
// discard if outside min/max range
//
if( (dist < minDist) || (dist > maxDist) )
{
continue;
}
// drop off the emission rate according to the falloff
// parameter, and divide to accound for multiple samples
// in the voxel
//
double distDrop = dropoff * distSquared;
double newVal = theRate * exp( -distDrop ) / (double)numSamples;
// emit density/heat/fuel/color into the current voxel
//
if( newVal != 0 )
{
fluid.emitIntoArrays( (float) newVal, i, j, k, (float)densityEmit, (float)heatEmit, (float)fuelEmit, doEmitColor, emitColor );
}
float *fArray = fluid.falloff();
if( fArray != NULL )
{
MPoint midPoint( x+0.5*dx, y+0.5*dy, z+0.5*dz );
midPoint.x *= 0.2;
midPoint.y *= 0.2;
midPoint.z *= 0.2;
float fdist = (float) sqrt( midPoint.x*midPoint.x + midPoint.y*midPoint.y + midPoint.z*midPoint.z );
fdist /= sqrtf(3.0f);
fArray[fluid.index(i,j,k)] = 1.0f-fdist;
}
}
}
}
}
}
}
void exportF3d::setF3dField(MFnFluid &fluidFn, const char *outputPath,
const MDagPath &dagPath)
{
try {
MStatus stat;
unsigned int i, xres = 0, yres = 0, zres = 0;
double xdim,ydim,zdim;
// Get the resolution of the fluid container
stat = fluidFn.getResolution(xres, yres, zres);
stat = fluidFn.getDimensions(xdim, ydim, zdim);
V3d size(xdim,ydim,zdim);
const V3i res(xres, yres, zres);
int psizeTot = fluidFn.gridSize();
/// get the transform and rotation
MObject parentObj = fluidFn.parent(0, &stat);
if (stat != MS::kSuccess) {
MGlobal::displayError("Can't find fluid's parent node");
return;
}
MDagPath parentPath = dagPath;
parentPath.pop();
MTransformationMatrix tmatFn(dagPath.inclusiveMatrix());
if (stat != MS::kSuccess) {
MGlobal::displayError("Failed to get transformation matrix of fluid's parent node");
return;
}
MFnTransform fnXform(parentPath, &stat);
if (stat != MS::kSuccess) {
MGlobal::displayError("Can't create a MFnTransform from fluid's parent node");
return;
}
if (m_verbose)
{
fprintf(stderr, "cellnum: %dx%dx%d = %d\n",
xres, yres, zres,psizeTot);
}
float *density(NULL), *temp(NULL), *fuel(NULL);
float *pressure(NULL), *falloff(NULL);
density = fluidFn.density( &stat );
if ( stat.error() ) m_density = false;
temp = fluidFn.temperature( &stat );
if ( stat.error() ) m_temperature = false;
fuel = fluidFn.fuel( &stat );
if ( stat.error() ) m_fuel = false;
pressure= fluidFn.pressure( &stat );
if ( stat.error() ) m_pressure = false;
falloff = fluidFn.falloff( &stat );
if ( stat.error() ) m_falloff = false;
float *r,*g,*b;
if (m_color) {
stat = fluidFn.getColors(r,b,g);
if ( stat.error() ) m_color = false;
}else
m_color = false;
float *u,*v,*w;
if (m_texture) {
stat = fluidFn.getCoordinates(u,v,w);
if ( stat.error() ) m_texture = false;
}else
m_texture = false;
/// velocity info
float *Xvel(NULL),*Yvel(NULL), *Zvel(NULL);
if (m_vel) {
stat = fluidFn.getVelocity( Xvel,Yvel,Zvel );
if ( stat.error() ) m_vel = false;
}
if (m_density == false && m_temperature==false && m_fuel==false &&
m_pressure==false && m_falloff==false && m_vel == false &&
m_color == false && m_texture==false)
{
MGlobal::displayError("No fluid attributes found for writing, please check fluids settings");
return;
}
/// Fields
DenseFieldf::Ptr densityFld, tempFld, fuelFld, pressureFld, falloffFld;
DenseField3f::Ptr CdFld, uvwFld;
MACField3f::Ptr vMac;
MPlug autoResizePlug = fluidFn.findPlug("autoResize", &stat);
bool autoResize;
autoResizePlug.getValue(autoResize);
// maya's fluid transformation
V3d dynamicOffset(0);
M44d localToWorld;
MatrixFieldMapping::Ptr mapping(new MatrixFieldMapping());
M44d fluid_mat(tmatFn.asMatrix().matrix);
if(autoResize) {
fluidFn.findPlug("dofx").getValue(dynamicOffset[0]);
fluidFn.findPlug("dofy").getValue(dynamicOffset[1]);
fluidFn.findPlug("dofz").getValue(dynamicOffset[2]);
}
Box3i extents;
extents.max = res - V3i(1);
extents.min = V3i(0);
mapping->setExtents(extents);
localToWorld.setScale(size);
localToWorld *= M44d().setTranslation( -(size*0.5) );
localToWorld *= M44d().setTranslation( dynamicOffset );
localToWorld *= fluid_mat;
mapping->setLocalToWorld(localToWorld);
if (m_density){
densityFld = new DenseFieldf;
densityFld->setSize(res);
densityFld->setMapping(mapping);
}
if (m_fuel){
fuelFld = new DenseFieldf;
fuelFld->setSize(res);
fuelFld->setMapping(mapping);
}
if (m_temperature){
tempFld = new DenseFieldf;
tempFld->setSize(res);
tempFld->setMapping(mapping);
}
if (m_pressure){
pressureFld = new DenseFieldf;
pressureFld->setSize(res);
pressureFld->setMapping(mapping);
}
if (m_falloff){
falloffFld = new DenseFieldf;
falloffFld->setSize(res);
falloffFld->setMapping(mapping);
}
if (m_vel){
vMac = new MACField3f;
vMac->setSize(res);
vMac->setMapping(mapping);
}
if (m_color){
CdFld = new DenseField3f;
CdFld->setSize(res);
CdFld->setMapping(mapping);
}
if (m_texture){
uvwFld = new DenseField3f;
uvwFld->setSize(res);
uvwFld->setMapping(mapping);
}
size_t iX, iY, iZ;
for( iZ = 0; iZ < zres; iZ++ )
{
for( iX = 0; iX < xres; iX++ )
{
for( iY = 0; iY < yres ; iY++ )
{
/// data is in x major but we are writting in z major order
i = fluidFn.index( iX, iY, iZ);
if ( m_density )
densityFld->lvalue(iX, iY, iZ) = density[i];
if ( m_temperature )
tempFld->lvalue(iX, iY, iZ) = temp[i];
if ( m_fuel )
fuelFld->lvalue(iX, iY, iZ) = fuel[i];
if ( m_pressure )
pressureFld->lvalue(iX, iY, iZ) = pressure[i];
if ( m_falloff )
falloffFld->lvalue(iX, iY, iZ) = falloff[i];
if (m_color)
CdFld->lvalue(iX, iY, iZ) = V3f(r[i], g[i], b[i]);
if (m_texture)
uvwFld->lvalue(iX, iY, iZ) = V3f(u[i], v[i], w[i]);
}
}
}
if (m_vel) {
unsigned x,y,z;
for(z=0;z<zres;++z) for(y=0;y<yres;++y) for(x=0;x<xres+1;++x) {
vMac->u(x,y,z) = *Xvel++;
}
for(z=0;z<zres;++z) for(y=0;y<yres+1;++y) for(x=0;x<xres;++x) {
vMac->v(x,y,z) = *Yvel++;
}
for(z=0;z<zres+1;++z) for(y=0;y<yres;++y) for(x=0;x<xres;++x) {
vMac->w(x,y,z) = *Zvel++;
}
}
Field3DOutputFile out;
if (!out.create(outputPath)) {
MGlobal::displayError("Couldn't create file: "+ MString(outputPath));
return;
}
string fieldname("maya");
if (m_density){
out.writeScalarLayer<float>(fieldname, "density", densityFld);
}
if (m_fuel) {
out.writeScalarLayer<float>(fieldname,"fuel", fuelFld);
}
if (m_temperature){
out.writeScalarLayer<float>(fieldname,"temperature", tempFld);
}
if (m_color) {
out.writeVectorLayer<float>(fieldname,"Cd", CdFld);
}
if (m_vel)
out.writeVectorLayer<float>(fieldname,"v_mac", vMac);
out.close();
}
catch(const std::exception &e)
{
MGlobal::displayError( MString(e.what()) );
return;
}
}