CacheMeshSampler::AttributeSet::AttributeSet(
MFnMesh& mesh,
const bool needUVs,
const bool useBaseTessellation
)
:fNumWires(0),
fNumTriangles(0),
fNumVerts(0)
{
// Refresh the internal shape, otherwise topo changes make mesh.numPolygons() crash.
// Note that buildShaderAssignmentGroups() also call mesh.numPolygons().
mesh.syncObject();
MDagPath dagPath;
mesh.getPath(dagPath);
// build a geometry request and add requirements to it.
MHWRender::MGeometryRequirements geomRequirements;
// Build descriptors to request the positions, normals and UVs
MVertexBufferDescriptor posDesc("", MGeometry::kPosition, MGeometry::kFloat, 3);
MVertexBufferDescriptor normalDesc("", MGeometry::kNormal, MGeometry::kFloat, 3);
MVertexBufferDescriptor uvDesc(mesh.currentUVSetName(), MGeometry::kTexture, MGeometry::kFloat, 2);
// add the descriptors to the geometry requirements
geomRequirements.addVertexRequirement(posDesc);
geomRequirements.addVertexRequirement(normalDesc);
if (needUVs)
geomRequirements.addVertexRequirement(uvDesc);
MString noName; // we do not need custom named index buffers here.
// create a component to include all elements.
MFnSingleIndexedComponent comp;
MObject compObj = comp.create(MFn::kMeshPolygonComponent);
comp.setCompleteData(mesh.numPolygons());
// create edge component
MFnSingleIndexedComponent edgeComp;
MObject edgeCompObj = edgeComp.create(MFn::kMeshEdgeComponent);
edgeComp.setCompleteData(mesh.numEdges());
// Add the edge line index buffer to the requirements
MIndexBufferDescriptor edgeDesc(MIndexBufferDescriptor::kEdgeLine, noName, MGeometry::kLines, 2, edgeCompObj);
geomRequirements.addIndexingRequirement(edgeDesc);
// add a triangle buffer to the requirements
MIndexBufferDescriptor triangleDesc(MIndexBufferDescriptor::kTriangle, noName, MGeometry::kTriangles, 3, compObj);
geomRequirements.addIndexingRequirement(triangleDesc);
typedef IndexBuffer::index_t index_t;
// We ignore the Smooth Preview option on the mesh shape node when
// using base tessellation.
int extractorOptions = MHWRender::kPolyGeom_Normal;
if (useBaseTessellation) {
extractorOptions |= MHWRender::kPolyGeom_BaseMesh;
}
// create an extractor to get the geometry
MStatus status;
MHWRender::MGeometryExtractor extractor(geomRequirements,dagPath, extractorOptions, &status);
if (MS::kFailure==status)
return;
// get the number of vertices from the extractor
unsigned int numVertices = extractor.vertexCount();
// get the number of primitives (triangles, lines, etc.)
unsigned int numWires = extractor.primitiveCount(edgeDesc);
// create the arrays that the generator will fill
boost::shared_array<float> vertices(new float[numVertices*posDesc.stride()]);
boost::shared_array<float> normals(new float[numVertices*normalDesc.stride()]);
boost::shared_array<float> uvs(new float[numVertices*uvDesc.stride()]);
unsigned int minBufferSize = extractor.minimumBufferSize(numWires, edgeDesc.primitive());
boost::shared_array<index_t> wireframeIdx(new index_t[minBufferSize]);
// populate the index buffer for the edges
if (MS::kFailure==extractor.populateIndexBuffer(wireframeIdx.get(), numWires, edgeDesc))
return;
// populate the vertex buffers you are interested in. (pos, normal, and uv)
if (MS::kFailure==extractor.populateVertexBuffer(vertices.get(), numVertices, posDesc))
return;
if (MS::kFailure==extractor.populateVertexBuffer(normals.get(), numVertices, normalDesc))
return;
if (needUVs && MS::kFailure==extractor.populateVertexBuffer(uvs.get(), numVertices, uvDesc))
return;
// populate the index buffers for all the triangle components
{
std::vector<boost::shared_ptr<Array<index_t> > > trgIdxGrps;
// get the index buffer count from the extractor
unsigned int numTriangles = extractor.primitiveCount(triangleDesc);
minBufferSize = extractor.minimumBufferSize(numTriangles, triangleDesc.primitive());
boost::shared_array<index_t> triangleIdx(new index_t[minBufferSize]);
if (numTriangles != 0)
{
if (MS::kFailure==extractor.populateIndexBuffer(triangleIdx.get(), numTriangles, triangleDesc))
return;
fNumTriangles += (size_t)numTriangles;
}
trgIdxGrps.push_back(SharedArray<index_t>::create(
triangleIdx, 3 * numTriangles));
for(size_t i=0, offset=0; i<trgIdxGrps.size(); ++i) {
fTriangleVertIndices.push_back(IndexBuffer::create(
trgIdxGrps[0], offset, offset + trgIdxGrps[i]->size()));
offset += trgIdxGrps[i]->size();
}
}
fNumWires = (size_t)numWires;
fNumVerts = (size_t)numVertices;
fWireVertIndices = IndexBuffer::create(
SharedArray<index_t>::create( wireframeIdx, 2 * fNumWires));
fPositions = VertexBuffer::createPositions(
SharedArray<float>::create( vertices, 3 * fNumVerts));
fNormals = VertexBuffer::createNormals(
SharedArray<float>::create( normals, 3 * fNumVerts));
if (needUVs) {
fUVs = VertexBuffer::createUVs(
SharedArray<float>::create(uvs, 2 * fNumVerts));
}
fBoundingBox = mesh.boundingBox();
// Check visibility
fVisibility = ShapeVisibilityChecker(mesh.object()).isVisible();
}
