MStatus MG_nurbsRivet::compute(const MPlug& plug,MDataBlock& dataBlock)
{
//Get recompute value
MDataHandle recomputeH = dataBlock.inputValue(recompute);
bool recomputeV = recomputeH.asBool();
//input mesh
MDataHandle inputNurbsH = dataBlock.inputValue(inputNurbSurface);
MObject inputNurb = inputNurbsH.asNurbsSurfaceTransformed();
MMatrix offsetMatrixV = dataBlock.inputValue(offsetMatrix).asMatrix();
double U,V;
MFnNurbsSurface nurbsFn ;
nurbsFn.setObject(inputNurb);
MStatus stat;
if (recomputeV == true)
{
//input point
MDataHandle inputPointH = dataBlock.inputValue(inputPoint);
MPoint inputP = inputPointH.asVector();
MPoint closestP = nurbsFn.closestPoint(inputP,NULL,NULL,false,1e+99,MSpace::kObject);
stat = nurbsFn.getParamAtPoint(closestP,U,V,MSpace::kObject);
//Handle to U and V
MDataHandle uValueH =dataBlock.outputValue(uValue);
MDataHandle vValueH =dataBlock.outputValue(vValue);
uValueH.set(float(U));
vValueH.set(float(V));
uValueH.setClean();
vValueH.setClean();
MDataHandle recomputeOutH = dataBlock.outputValue(recompute);
}
MDataHandle uH = dataBlock.inputValue(uValue);
MDataHandle vH = dataBlock.inputValue(vValue);
U = uH.asFloat();
V = vH.asFloat();
MPoint outPoint ;
MVector uVec ;
MVector vVec;
MVector normal;
//Get point
stat = nurbsFn.getPointAtParam(U,V,outPoint,MSpace::kObject);
//Since if getting both the U and V tangent was leading to some little rotation snapping
//of the rivet I only used the U tangent and calculated the next one by dot product
//of the normal and U tangent leading to a 100% stable rivet
nurbsFn.getTangents(U,V,uVec,vVec,MSpace::kObject);
uVec.normalize();
vVec.normalize();
MVector vVecCross;
//Get normal
normal = nurbsFn.normal(U,V,MSpace::kObject);
normal.normalize();
vVecCross =(uVec^normal);
//Build the maya matrix
double myMatrix[4][4]={ { uVec.x, uVec.y , uVec.z, 0},
{ normal[0], normal[1] , normal[2], 0},
{vVecCross.x, vVecCross.y , vVecCross.z, 0},
{ outPoint[0], outPoint[1] , outPoint[2], 1}};
MMatrix rotMatrix (myMatrix);
MMatrix offsetMatrixV2 = offsetMatrixV*rotMatrix;
MTransformationMatrix matrixFn(offsetMatrixV2);
double angles[3];
MTransformationMatrix::RotationOrder rotOrder;
rotOrder =MTransformationMatrix::kXYZ;
matrixFn.getRotation(angles,rotOrder,MSpace::kObject );
//get back radians value
double radX,radY,radZ;
radX=angles[0];
radY=angles[1];
radZ=angles[2];
//convert to degree
double rotX,rotY,rotZ;
rotX = radX*toDeg;
rotY = radY*toDeg;
rotZ = radZ*toDeg;
MDataHandle outputRotateH = dataBlock.outputValue(outputRotate);
outputRotateH.set3Double(rotX,rotY,rotZ);
outputRotateH.setClean();
//let set the output matrix too
MDataHandle outMH= dataBlock.outputValue(outputMatrix);
outMH.set(rotMatrix);
outMH.setClean();
MDataHandle outputH = dataBlock.outputValue(output);
outputH.set(offsetMatrixV2[3][0],offsetMatrixV2[3][1],offsetMatrixV2[3][2]);
outputH.setClean();
return MS::kSuccess;
}
