M
hi,
I've used this snippet to transform a mesh to a volume.
And this snippet allow to iterate trough voxel
the part that you have to be careful of are the parameter that you pass to MeshToVolume
specially gridSize, bandWidthInterior, bandWidthExterior.
for the conversionSettings you should not use DISABLE_INTERSECTING_VOXEL_REMOVAL
I've tried to use GetActiveVoxelDim that is an openVDB's function but it doesn't really work as i was expecting even for a cube.
iferr_scope;
if (doc == nullptr)
return maxon::IllegalArgumentError(MAXON_SOURCE_LOCATION, "document is nullptr"_s);
// Creates a cube to insert
BaseObject* cube = BaseObject::Alloc(Ocube);
if (cube == nullptr)
return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION, "not able to create a cube"_s);
ModelingCommandData mcd;
mcd.doc = doc;
mcd.op = cube;
// execute the "Current State to Object" modeling command
if (!SendModelingCommand(MCOMMAND_CURRENTSTATETOOBJECT, mcd))
return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
C4DAtom* atom = mcd.result->GetIndex(0);
BaseObject* const op = static_cast<BaseObject*>(atom);
PolygonObject* const polyObject = static_cast<PolygonObject*>(op);
doc->InsertObject(polyObject, nullptr, nullptr);
auto PolyToVolume = [](PolygonObject* const poly) -> maxon::Result<maxon::Volume>
{
iferr_scope;
// check polygon object data
const Vector* const points = poly->GetPointR();
const CPolygon* const polys = poly->GetPolygonR();
const maxon::Bool noPoints = points == nullptr;
const maxon::Bool noPolys = polys == nullptr;
if (noPoints || noPolys)
return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
// get polygon object data
const Int32 pointCount = poly->GetPointCount();
const Int32 polyCount = poly->GetPolygonCount();
const Matrix objectMatrix = poly->GetMg();
const maxon::COLLECTION_RESIZE_FLAGS flags = maxon::COLLECTION_RESIZE_FLAGS::ON_GROW_UNINITIALIZED;
// point array
maxon::BaseArray<maxon::Vector> volPoints;
volPoints.Resize(pointCount, flags) iferr_return;
// copy point data
for (Int32 pointIndex = 0; pointIndex < pointCount; ++pointIndex)
volPoints[pointIndex] = objectMatrix * points[pointIndex];
// polygon array
maxon::BaseArray<maxon::VolumeConversionPolygon> volPolys;
volPolys.Resize(polyCount, flags) iferr_return;
// copy polygon data
for (Int32 polyIndex = 0; polyIndex < polyCount; polyIndex++)
{
volPolys[polyIndex] = *reinterpret_cast<const maxon::VolumeConversionPolygon*>(&polys[polyIndex]);
if (polys[polyIndex].IsTriangle())
volPolys[polyIndex].SetTriangle();
}
const maxon::ThreadInterface* const thread = maxon::ThreadRef::GetCurrentThread().GetPointer();
if (thread == nullptr)
return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
const maxon::ThreadRef threadRef = const_cast<maxon::ThreadInterface*>(thread);
maxon::POLYGONCONVERSIONFLAGS conversionSettings = maxon::POLYGONCONVERSIONFLAGS::NONE;
conversionSettings |= maxon::POLYGONCONVERSIONFLAGS::DISABLE_RENORMALIZATION | maxon::POLYGONCONVERSIONFLAGS::DISABLE_NARROW_BAND_TRIMMING;
return maxon::VolumeToolsInterface::MeshToVolume(volPoints, volPolys, objectMatrix, 50.0, 0, 0, threadRef, conversionSettings);
};
// Use the lambda to transform a mesh to a volume
const maxon::Volume volumeA = PolyToVolume(polyObject) iferr_return;
// get matrix
const maxon::Matrix transform = volumeA.GetGridTransform();
// create iterator
maxon::GridIteratorRef<maxon::Float32, maxon::ITERATORTYPE::ON> iterator = maxon::GridIteratorRef<maxon::Float32, maxon::ITERATORTYPE::ON>::Create() iferr_return;
iterator.Init(volumeA) iferr_return;
maxon::IntVector32 dim = volumeA.GetActiveVoxelDim();
ApplicationOutput("dimension of voxels @", dim);
// create instance object
InstanceObject* const instance = InstanceObject::Alloc();
if (instance == nullptr)
return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION);
// insert object into the scene
doc->InsertObject(instance, nullptr, nullptr);
instance->SetParameter(INSTANCEOBJECT_RENDERINSTANCE_MODE, INSTANCEOBJECT_RENDERINSTANCE_MODE_MULTIINSTANCE, DESCFLAGS_SET::NONE);
// prepare matrices and colors
maxon::BaseArray<Matrix> matrices;
maxon::BaseArray<maxon::Color64> colors;
for (; iterator.IsNotAtEnd(); iterator.StepNext())
{
Float32 value = iterator.GetValue();
maxon::IntVector32 coord = iterator.GetCoords();
// set position
Vector pos;
pos.x = coord.x;
pos.y = coord.y;
pos.z = coord.z;
pos = transform * pos;
matrices.Append(MatrixMove(pos)) iferr_return;
Vector rgb = Vector(255, 0, 0);
if (value < 0.1)
rgb = Vector(0, 255, 0);
colors.Append(maxon::Color64(rgb)) iferr_return;
}
// store data in the instance object
instance->SetInstanceMatrices(matrices) iferr_return;
instance->SetInstanceColors(colors) iferr_return;
instance->SetParameter(INSTANCEOBJECT_DRAW_MODE, INSTANCEOBJECT_DRAW_MODE_POINTS, DESCFLAGS_SET::NONE);
EventAdd();
Cheers,
Manuel
