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///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2012-2018 DreamWorks Animation LLC
//
// All rights reserved. This software is distributed under the
// Mozilla Public License 2.0 ( http://www.mozilla.org/MPL/2.0/ )
//
// Redistributions of source code must retain the above copyright
// and license notice and the following restrictions and disclaimer.
//
// * Neither the name of DreamWorks Animation nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// IN NO EVENT SHALL THE COPYRIGHT HOLDERS' AND CONTRIBUTORS' AGGREGATE
// LIABILITY FOR ALL CLAIMS REGARDLESS OF THEIR BASIS EXCEED US$250.00.
//
///////////////////////////////////////////////////////////////////////////
#include <cppunit/extensions/HelperMacros.h>
#include <openvdb/openvdb.h>
#include <openvdb/tools/LevelSetSphere.h> // for createLevelSetSphere
#include <openvdb/tools/LevelSetUtil.h> // for sdfToFogVolume
#include <openvdb/tools/VolumeToSpheres.h> // for fillWithSpheres
#include <cmath>
#include <iostream>
#include <limits>
#include <vector>
class TestVolumeToSpheres: public CppUnit::TestCase
{
public:
CPPUNIT_TEST_SUITE(TestVolumeToSpheres);
CPPUNIT_TEST(testFromLevelSet);
CPPUNIT_TEST(testFromFog);
CPPUNIT_TEST(testMinimumSphereCount);
CPPUNIT_TEST(testClosestSurfacePoint);
CPPUNIT_TEST_SUITE_END();
void testFromLevelSet();
void testFromFog();
void testMinimumSphereCount();
void testClosestSurfacePoint();
};
CPPUNIT_TEST_SUITE_REGISTRATION(TestVolumeToSpheres);
////////////////////////////////////////
void
TestVolumeToSpheres::testFromLevelSet()
{
const float
radius = 20.0f,
voxelSize = 1.0f,
halfWidth = 3.0f;
const openvdb::Vec3f center(15.0f, 13.0f, 16.0f);
openvdb::FloatGrid::ConstPtr grid = openvdb::tools::createLevelSetSphere<openvdb::FloatGrid>(
radius, center, voxelSize, halfWidth);
const bool overlapping = false;
const int instanceCount = 10000;
const float
isovalue = 0.0f,
minRadius = 5.0f,
maxRadius = std::numeric_limits<float>::max();
const openvdb::Vec2i sphereCount(1, 100);
{
std::vector<openvdb::Vec4s> spheres;
openvdb::tools::fillWithSpheres(*grid, spheres, sphereCount, overlapping,
minRadius, maxRadius, isovalue, instanceCount);
CPPUNIT_ASSERT_EQUAL(1, int(spheres.size()));
//for (size_t i=0; i< spheres.size(); ++i) {
// std::cout << "\nSphere #" << i << ": " << spheres[i] << std::endl;
//}
const auto tolerance = 2.0 * voxelSize;
CPPUNIT_ASSERT_DOUBLES_EQUAL(center[0], spheres[0][0], tolerance);
CPPUNIT_ASSERT_DOUBLES_EQUAL(center[1], spheres[0][1], tolerance);
CPPUNIT_ASSERT_DOUBLES_EQUAL(center[2], spheres[0][2], tolerance);
CPPUNIT_ASSERT_DOUBLES_EQUAL(radius, spheres[0][3], tolerance);
}
{
// Verify that an isovalue outside the narrow band still produces a valid sphere.
std::vector<openvdb::Vec4s> spheres;
openvdb::tools::fillWithSpheres(*grid, spheres, sphereCount,
overlapping, minRadius, maxRadius, 1.5f * halfWidth, instanceCount);
CPPUNIT_ASSERT_EQUAL(1, int(spheres.size()));
}
{
// Verify that an isovalue inside the narrow band produces no spheres.
std::vector<openvdb::Vec4s> spheres;
openvdb::tools::fillWithSpheres(*grid, spheres, sphereCount,
overlapping, minRadius, maxRadius, -1.5f * halfWidth, instanceCount);
CPPUNIT_ASSERT_EQUAL(0, int(spheres.size()));
}
}
void
TestVolumeToSpheres::testFromFog()
{
const float
radius = 20.0f,
voxelSize = 1.0f,
halfWidth = 3.0f;
const openvdb::Vec3f center(15.0f, 13.0f, 16.0f);
auto grid = openvdb::tools::createLevelSetSphere<openvdb::FloatGrid>(
radius, center, voxelSize, halfWidth);
openvdb::tools::sdfToFogVolume(*grid);
const bool overlapping = false;
const int instanceCount = 10000;
const float
isovalue = 0.01f,
minRadius = 5.0f,
maxRadius = std::numeric_limits<float>::max();
const openvdb::Vec2i sphereCount(1, 100);
{
std::vector<openvdb::Vec4s> spheres;
openvdb::tools::fillWithSpheres(*grid, spheres, sphereCount, overlapping,
minRadius, maxRadius, isovalue, instanceCount);
//for (size_t i=0; i< spheres.size(); ++i) {
// std::cout << "\nSphere #" << i << ": " << spheres[i] << std::endl;
//}
CPPUNIT_ASSERT_EQUAL(1, int(spheres.size()));
const auto tolerance = 2.0 * voxelSize;
CPPUNIT_ASSERT_DOUBLES_EQUAL(center[0], spheres[0][0], tolerance);
CPPUNIT_ASSERT_DOUBLES_EQUAL(center[1], spheres[0][1], tolerance);
CPPUNIT_ASSERT_DOUBLES_EQUAL(center[2], spheres[0][2], tolerance);
CPPUNIT_ASSERT_DOUBLES_EQUAL(radius, spheres[0][3], tolerance);
}
{
// Verify that an isovalue outside the narrow band still produces valid spheres.
std::vector<openvdb::Vec4s> spheres;
openvdb::tools::fillWithSpheres(*grid, spheres, sphereCount, overlapping,
minRadius, maxRadius, 10.0f, instanceCount);
CPPUNIT_ASSERT(!spheres.empty());
}
}
void
TestVolumeToSpheres::testMinimumSphereCount()
{
using namespace openvdb;
{
auto grid = tools::createLevelSetSphere<FloatGrid>(/*radius=*/5.0f,
/*center=*/Vec3f(15.0f, 13.0f, 16.0f), /*voxelSize=*/1.0f, /*halfWidth=*/3.0f);
// Verify that the requested minimum number of spheres is generated, for various minima.
const int maxSphereCount = 100;
for (int minSphereCount = 1; minSphereCount < 20; minSphereCount += 5) {
std::vector<Vec4s> spheres;
tools::fillWithSpheres(*grid, spheres, Vec2i(minSphereCount, maxSphereCount),
/*overlapping=*/true, /*minRadius=*/2.0f);
// Given the relatively large minimum radius, the actual sphere count
// should be no larger than the requested mimimum count.
CPPUNIT_ASSERT_EQUAL(minSphereCount, int(spheres.size()));
//CPPUNIT_ASSERT(int(spheres.size()) >= minSphereCount);
CPPUNIT_ASSERT(int(spheres.size()) <= maxSphereCount);
}
}
{
// One step in the sphere packing algorithm is to erode the active voxel mask
// of the input grid. Previously, for very small grids this sometimes resulted in
// an empty mask and therefore no spheres. Verify that that no longer happens
// (as long as the minimum sphere count is nonzero).
FloatGrid grid;
CoordBBox bbox(Coord(1), Coord(2));
grid.fill(bbox, 1.0f);
const float minRadius = 1.0f;
const Vec2i sphereCount(5, 100);
std::vector<Vec4s> spheres;
tools::fillWithSpheres(grid, spheres, sphereCount, /*overlapping=*/true, minRadius);
CPPUNIT_ASSERT(int(spheres.size()) >= sphereCount[0]);
}
}
void
TestVolumeToSpheres::testClosestSurfacePoint()
{
using namespace openvdb;
const float voxelSize = 1.0f;
const Vec3f center{0.0f}; // ensure multiple internal nodes
for (const float radius: { 8.0f, 50.0f }) {
// Construct a spherical level set.
const auto sphere = tools::createLevelSetSphere<FloatGrid>(radius, center, voxelSize);
CPPUNIT_ASSERT(sphere);
// Construct the corners of a cube that exactly encloses the sphere.
const std::vector<Vec3R> corners{
{ -radius, -radius, -radius },
{ -radius, -radius, radius },
{ -radius, radius, -radius },
{ -radius, radius, radius },
{ radius, -radius, -radius },
{ radius, -radius, radius },
{ radius, radius, -radius },
{ radius, radius, radius },
};
// Compute the distance from a corner of the cube to the surface of the sphere.
const auto distToSurface = Vec3d{radius}.length() - radius;
auto csp = tools::ClosestSurfacePoint<FloatGrid>::create(*sphere);
CPPUNIT_ASSERT(csp);
// Move each corner point to the closest surface point.
auto points = corners;
std::vector<float> distances;
bool ok = csp->searchAndReplace(points, distances);
CPPUNIT_ASSERT(ok);
CPPUNIT_ASSERT_EQUAL(8, int(points.size()));
CPPUNIT_ASSERT_EQUAL(8, int(distances.size()));
for (auto d: distances) {
CPPUNIT_ASSERT((std::abs(d - distToSurface) / distToSurface) < 0.01); // rel err < 1%
}
for (int i = 0; i < 8; ++i) {
const auto intersection = corners[i] + distToSurface * (center - corners[i]).unit();
CPPUNIT_ASSERT(points[i].eq(intersection, /*tolerance=*/0.1));
}
// Place a point inside the sphere.
points.clear();
distances.clear();
points.emplace_back(1, 0, 0);
ok = csp->searchAndReplace(points, distances);
CPPUNIT_ASSERT(ok);
CPPUNIT_ASSERT_EQUAL(1, int(points.size()));
CPPUNIT_ASSERT_EQUAL(1, int(distances.size()));
CPPUNIT_ASSERT((std::abs(radius - 1 - distances[0]) / (radius - 1)) < 0.01);
CPPUNIT_ASSERT(points[0].eq(Vec3R{radius, 0, 0}, /*tolerance=*/0.5));
///< @todo off by half a voxel in y and z
}
}
// Copyright (c) 2012-2018 DreamWorks Animation LLC
// All rights reserved. This software is distributed under the
// Mozilla Public License 2.0 ( http://www.mozilla.org/MPL/2.0/ )
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