// Initialize the OpenVDB library. This must be called at least

// once per program and may safely be called multiple times.

openvdb::initialize();

// Create an empty floating-point grid with background value 0.

openvdb::FloatGrid::Ptr grid = openvdb::FloatGrid::create();

std::cout << "Testing random access:" << std::endl;

// Get an accessor for coordinate-based access to voxels.

openvdb::FloatGrid::Accessor accessor = grid->getAccessor();

// Define a coordinate with large signed indices.

openvdb::Coord xyz(1000, -200000000, 30000000);

// Set the voxel value at (1000, -200000000, 30000000) to 1.

accessor.setValue(xyz, 1.0);

// Verify that the voxel value at (1000, -200000000, 30000000) is 1.

std::cout << "Grid" << xyz << " = " << accessor.getValue(xyz) << std::endl;

// Reset the coordinates to those of a different voxel.

xyz.reset(1000, 200000000, -30000000);

// Verify that the voxel value at (1000, 200000000, -30000000) is

// the background value, 0.

std::cout << "Grid" << xyz << " = " << accessor.getValue(xyz) << std::endl;

// Set the voxel value at (1000, 200000000, -30000000) to 2.

accessor.setValue(xyz, 2.0);

// Set the voxels at the two extremes of the available coordinate space.

// For 32-bit signed coordinates these are (-2147483648, -2147483648,

// -2147483648) and (2147483647, 2147483647, 2147483647).

accessor.setValue(openvdb::Coord::min(), 3.0f);

accessor.setValue(openvdb::Coord::max(), 4.0f);

std::cout << "Testing sequential access:" << std::endl;

// Print all active ("on") voxels by means of an iterator.

for (openvdb::FloatGrid::ValueOnCIter iter = grid->cbeginValueOn(); iter;

++iter) {

std::cout << "Grid" << iter.getCoord() << " = " << *iter << std::endl;

}