// Returns an Intersection of the ray with a sphere
Intersection Mesh::intersectImpl(const Ray &ray) const {
Intersection i = Intersection();
i.t = -1.0f;
i.normal = glm::vec3(0.f);
float smallestT = FLT_MAX;
// check every triangle in the mesh
int num_triangles = indices_.size() / 3;
for (int n = 0; n < num_triangles; ++n) {
// triangle vertices
glm::vec3 p1 = vertices_.at(indices_.at(n * 3));
glm::vec3 p2 = vertices_.at(indices_.at(n * 3 + 1));
glm::vec3 p3 = vertices_.at(indices_.at(n * 3 + 2));
// triangle intersection
Intersection triI = triangleIntersect(ray, p1, p2, p3);
// return only the closest triangle
if (triI.t != -1.0 && triI.t < smallestT) {
smallestT = triI.t;
i = triI;
}
}
return i;
}
void LinkedNode::subdivide(DirectX::XMFLOAT3 p_min,
DirectX::XMFLOAT3 p_max,
std::vector<unsigned int> p_indices,
std::vector<Triangle> p_triangles)
{
std::vector<unsigned int> triIndices;
bool intersect = false;
for(unsigned int i=0; i<p_indices.size(); i++)
{
intersect = triangleIntersect(p_triangles[p_indices[i]]);
if(intersect)
triIndices.push_back(p_indices[i]);
}
if(triIndices.size() > MAX_NUM_TRIS)
{
DirectX::XMFLOAT3 minValues[8];
DirectX::XMFLOAT3 maxValues[8];
minValues[0] = p_min;
maxValues[0] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, (p_min.y+p_max.y)/2 , (p_min.z+p_max.z)/2 );
minValues[1] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, p_min.y, p_min.z );
maxValues[1] = DirectX::XMFLOAT3( p_max.x, (p_min.y+p_max.y)/2 , (p_min.z+p_max.z)/2 );
minValues[2] = DirectX::XMFLOAT3( p_min.x, p_min.y, (p_min.z+p_max.z)/2 );
maxValues[2] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, (p_min.y+p_max.y)/2 , p_max.z );
minValues[3] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, p_min.y, (p_min.z+p_max.z)/2 );
maxValues[3] = DirectX::XMFLOAT3( p_max.x, (p_min.y+p_max.y)/2 , p_max.z );
minValues[4] = DirectX::XMFLOAT3( p_min.x, (p_min.y+p_max.y)/2, p_min.z );
maxValues[4] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, p_max.y , (p_min.z+p_max.z)/2 );
minValues[5] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, (p_min.y+p_max.y)/2, p_min.z );
maxValues[5] = DirectX::XMFLOAT3( p_max.x, p_max.y , (p_min.z+p_max.z)/2 );
minValues[6] = DirectX::XMFLOAT3( p_min.x, (p_min.y+p_max.y)/2, (p_min.z+p_max.z)/2 );
maxValues[6] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, p_max.y, p_max.z );
minValues[7] = DirectX::XMFLOAT3( (p_min.x+p_max.x)/2, (p_min.y+p_max.y)/2, (p_min.z+p_max.z)/2 );
maxValues[7] = DirectX::XMFLOAT3( p_max.x, p_max.y, p_max.z );
for(unsigned int i=0; i<NUM_CHILDREN; i++)
{
m_children[i] = new LinkedNode(minValues[i], maxValues[i]);
m_children[i]->subdivide(minValues[i], maxValues[i], triIndices, p_triangles);
}
}
else
m_triIndices = triIndices;
}
char BaseMesh::intersect(unsigned idx, IntersectionContext * ctx) const
{
Vector3F threeCorners[3];
threeCorners[0] = _vertices[_indices[idx * 3]];
threeCorners[1] = _vertices[_indices[idx * 3 + 1]];
threeCorners[2] = _vertices[_indices[idx * 3 + 2]];
if(!triangleIntersect(threeCorners, ctx)) return 0;
postIntersection(idx, ctx);
return 1;
}
// custom implement R04922067 begin
bool Heightfield2::Intersect(const Ray &r, float *tHit, float *rayEpsilon,
DifferentialGeometry *dg) const {
// Transform _Ray_ to object space
Ray ray;
(*WorldToObject)(r, &ray);
// simplify 3D DDA to 2D DDA
int x, y;
bool has = false;
for (y = 0; y < ny-1; ++y) {
for (x = 0; x < nx-1; ++x) {
float tx[2], ty[2];
float tz[4] = {z[y*nx+x], z[y*nx+(x+1)], z[(y+1)*nx+x], z[(y+1)*nx+x+1]};
tx[0] = (float)x / (float) (nx-1);
ty[0] = (float)y / (float) (ny-1);
tx[1] = (float)(x+1) / (float) (nx-1);
ty[1] = (float)(y+1) / (float) (ny-1);
Point p[4];
p[0].x = tx[0], p[0].y = ty[0], p[0].z = tz[0]; // (0, 0)
p[1].x = tx[1], p[1].y = ty[0], p[1].z = tz[1]; // (1, 0)
p[2].x = tx[0], p[2].y = ty[1], p[2].z = tz[2]; // (0, 1)
p[3].x = tx[1], p[3].y = ty[1], p[3].z = tz[3]; // (1, 1)
{
Point triangle[3] = {p[0], p[1], p[3]};
if (triangleIntersect(r, tHit, rayEpsilon, dg, triangle)) {
has = true;
}
}
{
Point triangle[3] = {p[0], p[3], p[2]};
if (triangleIntersect(r, tHit, rayEpsilon, dg, triangle)) {
has = true;
}
}
}
}
return has;
}
char BaseMesh::selectComponent(IntersectionContext * ctx) const
{
Vector3F threeCorners[3];
unsigned fvi[3];
const unsigned nf = getNumTriangles();
for(unsigned i = 0; i < nf; i++) {
getTriangle(i, fvi);
threeCorners[0] = _vertices[fvi[0]];
threeCorners[1] = _vertices[fvi[1]];
threeCorners[2] = _vertices[fvi[2]];
if(triangleIntersect(threeCorners, ctx)) {
ctx->m_componentIdx = BaseMesh::closestVertex(i, ctx->m_hitP);;
return 1;
}
}
return 0;
}
