Function meshRayIntersect_

source/MRMesh/MRMeshIntersect.cpp:21–134

template<typename T>
MeshIntersectionResult meshRayIntersect_( const MeshPart& meshPart, const Line3<T>& line,
    T rayStart, T rayEnd, const IntersectionPrecomputes<T>& prec, bool closestIntersect, const FacePredicate & validFaces )
{
    const auto& m = meshPart.mesh;
    const auto& tree = m.getAABBTree();
    MeshIntersectionResult res;
    if( tree.nodes().empty() )
        return res;

    RayOrigin<T> rayOrigin{ line.p };
    T s = rayStart, e = rayEnd;
    if( !rayBoxIntersect( Box3<T>{ tree[tree.rootNodeId()].box }, rayOrigin, s, e, prec ) )
        return res;

    constexpr int maxTreeDepth = 32;
    std::pair< NodeId,T> nodesStack[maxTreeDepth];
    int currentNode = 0;
    nodesStack[0] = { tree.rootNodeId(), rayStart };

    TriPointf triP;
    while( currentNode >= 0 && ( closestIntersect || !res.proj.face ) )
    {
        if( currentNode >= maxTreeDepth ) // max depth exceeded
        {
            spdlog::critical( "Maximal AABBTree depth reached!" );
            assert( false );
            break;
        }

        const auto& node = tree[nodesStack[currentNode].first];
        if( nodesStack[currentNode--].second < rayEnd )
        {
            if( node.leaf() )
            {
                auto face = node.leafId();
                if( ( !meshPart.region || meshPart.region->test( face ) ) && ( !validFaces || validFaces( face ) ) )
                {
                    VertId a, b, c;
                    m.topology.getTriVerts( face, a, b, c );

                    const Vector3<T> vA = Vector3<T>( m.points[a] ) - line.p;
                    const Vector3<T> vB = Vector3<T>( m.points[b] ) - line.p;
                    const Vector3<T> vC = Vector3<T>( m.points[c] ) - line.p;
                    if ( auto triIsect = rayTriangleIntersect( vA, vB, vC, prec ) )
                    {
                        const T t( triIsect->t );
                        if ( t < rayEnd && t > rayStart )
                        {
                            res.distanceAlongLine = triIsect->t;
                            res.proj.face = face;
                            triP = triIsect->bary;
                            if ( t == 0 )
                            {
                                rayStart = rayEnd = 0;
                                break; // intersection exactly at ray origin
                            }
                            if ( t < 0 )
                            {