void Atlas::extractCharts()
{
const uint faceCount = m_mesh->faceCount();
int first = 0;
Array<uint> queue(faceCount);
BitArray bitFlags(faceCount);
bitFlags.clearAll();
for (uint f = 0; f < faceCount; f++)
{
if (bitFlags.bitAt(f) == false)
{
// Start new patch. Reset queue.
first = 0;
queue.clear();
queue.append(f);
bitFlags.setBitAt(f);
while (first != queue.count())
{
const HalfEdge::Face * face = m_mesh->faceAt(queue[first]);
// Visit face neighbors of queue[first]
for (HalfEdge::Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
{
const HalfEdge::Edge * edge = it.current();
nvDebugCheck(edge->pair != NULL);
if (!edge->isBoundary() && /*!edge->isSeam()*/
//!(edge->from()->tex() != edge->pair()->to()->tex() || edge->to()->tex() != edge->pair()->from()->tex()))
!(edge->from() != edge->pair->to() || edge->to() != edge->pair->from())) // Preserve existing seams (not just texture seams).
{
const HalfEdge::Face * neighborFace = edge->pair->face;
nvDebugCheck(neighborFace != NULL);
if (bitFlags.bitAt(neighborFace->id) == false)
{
queue.append(neighborFace->id);
bitFlags.setBitAt(neighborFace->id);
}
}
}
first++;
}
Chart * chart = new Chart();
chart->build(m_mesh, queue);
m_chartArray.append(chart);
}
}
}
void Atlas::computeCharts(const SegmentationSettings & settings)
{
AtlasBuilder builder(m_mesh);
// Tweak these values:
const float maxThreshold = 2;
const uint growFaceCount = 32;
const uint maxIterations = 4;
builder.settings = settings;
//builder.settings.proxyFitMetricWeight *= 0.75; // relax proxy fit weight during initial seed placement.
//builder.settings.roundnessMetricWeight = 0;
//builder.settings.straightnessMetricWeight = 0;
// This seems a reasonable estimate.
uint maxSeedCount = max(6U, m_mesh->faceCount());
// Create initial charts greedely.
nvDebug("### Placing seeds\n");
builder.placeSeeds(maxThreshold, maxSeedCount);
nvDebug("### Placed %d seeds (max = %d)\n", builder.chartCount(), maxSeedCount);
builder.updateProxies();
builder.mergeCharts();
#if 1
nvDebug("### Relocating seeds\n");
builder.relocateSeeds();
nvDebug("### Reset charts\n");
builder.resetCharts();
builder.settings = settings;
nvDebug("### Growing charts\n");
// Restart process growing charts in parallel.
uint iteration = 0;
while (true)
{
if (!builder.growCharts(maxThreshold, growFaceCount))
{
nvDebug("### Can't grow anymore\n");
// If charts cannot grow more: fill holes, merge charts, relocate seeds and start new iteration.
nvDebug("### Filling holes\n");
builder.fillHoles(maxThreshold);
nvDebug("### Using %d charts now\n", builder.chartCount());
builder.updateProxies();
nvDebug("### Merging charts\n");
builder.mergeCharts();
nvDebug("### Using %d charts now\n", builder.chartCount());
nvDebug("### Reseeding\n");
if (!builder.relocateSeeds())
{
nvDebug("### Cannot relocate seeds anymore\n");
// Done!
break;
}
if (iteration == maxIterations)
{
nvDebug("### Reached iteration limit\n");
break;
}
iteration++;
nvDebug("### Reset charts\n");
builder.resetCharts();
nvDebug("### Growing charts\n");
}
};
#endif
// Make sure no holes are left!
nvDebugCheck(builder.facesLeft == 0);
const uint chartCount = builder.chartArray.count();
for (uint i = 0; i < chartCount; i++)
{
Chart * chart = new Chart();
m_chartArray.append(chart);
chart->build(m_mesh, builder.chartFaces(i));
}
// Build face indices.
m_faceChart.resize(m_mesh->faceCount());
m_faceIndex.resize(m_mesh->faceCount());
for (uint i = 0; i < chartCount; i++)
{
const Chart * chart = m_chartArray[i];
const uint faceCount = chart->faceCount();
for (uint f = 0; f < faceCount; f++)
{
uint idx = chart->faceAt(f);
m_faceChart[idx] = i;
m_faceIndex[idx] = f;
}
}
// Build an exclusive prefix sum of the chart vertex counts.
m_chartVertexCountPrefixSum.resize(chartCount);
if (chartCount > 0)
{
m_chartVertexCountPrefixSum[0] = 0;
for (uint i = 1; i < chartCount; i++)
{
const Chart * chart = m_chartArray[i-1];
m_chartVertexCountPrefixSum[i] = m_chartVertexCountPrefixSum[i-1] + chart->vertexCount();
}
m_totalVertexCount = m_chartVertexCountPrefixSum[chartCount - 1] + m_chartArray[chartCount-1]->vertexCount();
}
else
{
m_totalVertexCount = 0;
}
}