void MayaNurbsCurveWriter::write()
{
Alembic::AbcGeom::OCurvesSchema::Sample samp;
samp.setBasis(Alembic::AbcGeom::kBsplineBasis);
MStatus stat;
mCVCount = 0;
// if inheritTransform is on and the curve group is animated,
// bake the cv positions in the world space
MMatrix exclusiveMatrixInv = mRootDagPath.exclusiveMatrixInverse(&stat);
std::size_t numCurves = 1;
if (mIsCurveGrp)
numCurves = mNurbsCurves.length();
std::vector<Alembic::Util::int32_t> nVertices(numCurves);
std::vector<float> points;
std::vector<float> width;
std::vector<float> knots;
std::vector<Alembic::Util::uint8_t> orders(numCurves);
MMatrix transformMatrix;
bool useConstWidth = false;
MFnDependencyNode dep(mRootDagPath.transform());
MPlug constWidthPlug = dep.findPlug("width");
if (!constWidthPlug.isNull())
{
useConstWidth = true;
width.push_back(constWidthPlug.asFloat());
}
for (unsigned int i = 0; i < numCurves; i++)
{
MFnNurbsCurve curve;
if (mIsCurveGrp)
{
curve.setObject(mNurbsCurves[i]);
MMatrix inclusiveMatrix = mNurbsCurves[i].inclusiveMatrix(&stat);
transformMatrix = inclusiveMatrix*exclusiveMatrixInv;
}
else
{
curve.setObject(mRootDagPath.node());
}
if (i == 0)
{
if (curve.form() == MFnNurbsCurve::kOpen)
{
samp.setWrap(Alembic::AbcGeom::kNonPeriodic);
}
else
{
samp.setWrap(Alembic::AbcGeom::kPeriodic);
}
if (curve.degree() == 3)
{
samp.setType(Alembic::AbcGeom::kCubic);
}
else if (curve.degree() == 1)
{
samp.setType(Alembic::AbcGeom::kLinear);
}
else
{
samp.setType(Alembic::AbcGeom::kVariableOrder);
}
}
else
{
if (curve.form() == MFnNurbsCurve::kOpen)
{
samp.setWrap(Alembic::AbcGeom::kNonPeriodic);
}
if ((samp.getType() == Alembic::AbcGeom::kCubic &&
curve.degree() != 3) ||
(samp.getType() == Alembic::AbcGeom::kLinear &&
curve.degree() != 1))
{
samp.setType(Alembic::AbcGeom::kVariableOrder);
}
}
orders[i] = static_cast<Alembic::Util::uint8_t>(curve.degree() + 1);
Alembic::Util::int32_t numCVs = curve.numCVs(&stat);
MPointArray cvArray;
stat = curve.getCVs(cvArray, MSpace::kObject);
mCVCount += numCVs;
nVertices[i] = numCVs;
for (Alembic::Util::int32_t j = 0; j < numCVs; j++)
{
MPoint transformdPt;
if (mIsCurveGrp)
{
transformdPt = cvArray[j]*transformMatrix;
}
else
{
transformdPt = cvArray[j];
}
points.push_back(static_cast<float>(transformdPt.x));
points.push_back(static_cast<float>(transformdPt.y));
points.push_back(static_cast<float>(transformdPt.z));
}
MDoubleArray knotsArray;
curve.getKnots(knotsArray);
knots.reserve(knotsArray.length() + 2);
// need to add a knot to the start and end (M + 2N + 1)
if (knotsArray.length() > 1)
{
unsigned int knotsLength = knotsArray.length();
if (knotsArray[0] == knotsArray[knotsLength - 1] ||
knotsArray[0] == knotsArray[1])
{
knots.push_back(knotsArray[0]);
}
else
{
knots.push_back(2 * knotsArray[0] - knotsArray[1]);
}
for (unsigned int j = 0; j < knotsLength; ++j)
{
knots.push_back(knotsArray[j]);
}
if (knotsArray[0] == knotsArray[knotsLength - 1] ||
knotsArray[knotsLength - 1] == knotsArray[knotsLength - 2])
{
knots.push_back(knotsArray[knotsLength - 1]);
}
else
{
knots.push_back(2 * knotsArray[knotsLength - 1] -
knotsArray[knotsLength - 2]);
}
}
// width
MPlug widthPlug = curve.findPlug("width");
if (!useConstWidth && !widthPlug.isNull())
{
MObject widthObj;
MStatus status = widthPlug.getValue(widthObj);
MFnDoubleArrayData fnDoubleArrayData(widthObj, &status);
MDoubleArray doubleArrayData = fnDoubleArrayData.array();
Alembic::Util::int32_t arraySum = doubleArrayData.length();
if (arraySum == numCVs)
{
for (Alembic::Util::int32_t i = 0; i < arraySum; i++)
{
width.push_back(static_cast<float>(doubleArrayData[i]));
}
}
else if (status == MS::kSuccess)
{
MString msg = "Curve ";
msg += curve.partialPathName();
msg += " has incorrect size for the width vector.";
msg += "\nUsing default constant width of 0.1.";
MGlobal::displayWarning(msg);
width.clear();
width.push_back(0.1f);
useConstWidth = true;
}
else
{
width.push_back(widthPlug.asFloat());
useConstWidth = true;
}
}
else if (!useConstWidth)
{
// pick a default value
width.clear();
width.push_back(0.1f);
useConstWidth = true;
}
}
Alembic::AbcGeom::GeometryScope scope = Alembic::AbcGeom::kVertexScope;
if (useConstWidth)
scope = Alembic::AbcGeom::kConstantScope;
samp.setCurvesNumVertices(Alembic::Abc::Int32ArraySample(nVertices));
samp.setPositions(Alembic::Abc::V3fArraySample(
(const Imath::V3f *)&points.front(), points.size() / 3 ));
samp.setWidths(Alembic::AbcGeom::OFloatGeomParam::Sample(
Alembic::Abc::FloatArraySample(width), scope) );
if (samp.getType() == Alembic::AbcGeom::kVariableOrder)
{
samp.setOrders(Alembic::Abc::UcharArraySample(orders));
}
if (!knots.empty())
{
samp.setKnots(Alembic::Abc::FloatArraySample(knots));
}
mSchema.set(samp);
}
IECore::PrimitivePtr FromMayaCurveConverter::doPrimitiveConversion( MFnNurbsCurve &fnCurve ) const
{
// decide on the basis and periodicity
int mDegree = fnCurve.degree();
IECore::CubicBasisf basis = IECore::CubicBasisf::linear();
if( m_linearParameter->getTypedValue()==false && mDegree==3 )
{
basis = IECore::CubicBasisf::bSpline();
}
bool periodic = false;
if( fnCurve.form()==MFnNurbsCurve::kPeriodic )
{
periodic = true;
}
// get the points and convert them
MPointArray mPoints;
fnCurve.getCVs( mPoints, space() );
if( periodic )
{
// maya duplicates the first points at the end, whereas we just wrap around.
// remove the duplicates.
mPoints.setLength( mPoints.length() - mDegree );
}
bool duplicateEnds = false;
if( !periodic && mDegree==3 )
{
// there's an implicit duplication of the end points that we need to make explicit
duplicateEnds = true;
}
IECore::V3fVectorDataPtr pointsData = new IECore::V3fVectorData;
std::vector<Imath::V3f> &points = pointsData->writable();
std::vector<Imath::V3f>::iterator transformDst;
if( duplicateEnds )
{
points.resize( mPoints.length() + 4 );
transformDst = points.begin();
*transformDst++ = IECore::convert<Imath::V3f>( mPoints[0] );
*transformDst++ = IECore::convert<Imath::V3f>( mPoints[0] );
}
else
{
points.resize( mPoints.length() );
transformDst = points.begin();
}
std::transform( MArrayIter<MPointArray>::begin( mPoints ), MArrayIter<MPointArray>::end( mPoints ), transformDst, IECore::VecConvert<MPoint, V3f>() );
if( duplicateEnds )
{
points[points.size()-1] = IECore::convert<Imath::V3f>( mPoints[mPoints.length()-1] );
points[points.size()-2] = IECore::convert<Imath::V3f>( mPoints[mPoints.length()-1] );
}
// make and return the curve
IECore::IntVectorDataPtr vertsPerCurve = new IECore::IntVectorData;
vertsPerCurve->writable().push_back( points.size() );
return new IECore::CurvesPrimitive( vertsPerCurve, basis, periodic, pointsData );
}
