void reduction_entropy::
update_normal(shared_surfel target_surfel_ptr,
shared_entropy_surfel_vector const neighbour_ptrs) const{
vec3f new_normal(0.0, 0.0, 0.0);
real weight_sum = 0.f;
new_normal = target_surfel_ptr->normal();
weight_sum = 1.0;
for(auto const neighbour_ptr : neighbour_ptrs){
shared_surfel target_surfel_ptr = neighbour_ptr->contained_surfel;
real weight = target_surfel_ptr->radius();
weight_sum += weight;
new_normal += weight * target_surfel_ptr->normal();
}
if( weight_sum != 0.0 ) {
new_normal /= weight_sum;
} else {
new_normal = vec3r(0.0, 0.0, 0.0);
}
target_surfel_ptr->normal() = scm::math::normalize(new_normal);
}
inline Eigen::Affine3f tf_from_plane_model(float a, float b, float c, float d) {
Eigen::Vector3f new_normal(a, b, c);
Eigen::Vector3f old_normal(0, 0, 1);
Eigen::Vector3f v = old_normal.cross(new_normal);
float s2 = v.squaredNorm();
float cc = old_normal.dot(new_normal);
Eigen::Matrix3f v_cross;
v_cross << 0, -v(2), v(1), v(2), 0, -v(0), -v(1), v(0), 0;
Eigen::Matrix3f rot = Eigen::Matrix3f::Identity() + v_cross + v_cross * v_cross * (1 - cc) / s2;
Eigen::Affine3f arot(rot);
// Create a transform where the rotation component is given by the rotation axis as the normal vector (a, b, c)
// and some arbitrary angle about that axis and the translation component is -d in the z direction after
// that rotation (not the original z direction, which is how transforms are usually defined).
auto result = Eigen::Translation3f(0, 0, d) * arot.inverse();
return result;
}
void cylinder(ProtectedPtr<Mesh> mesh, float diameter, float length, int32_t segments, int32_t stacks) {
float radius = diameter * 0.5;
float delta_angle = (kmPI * 2.0) / (float) segments;
float delta_height = length / (float) stacks;
int offset = 0;
auto smi = mesh->new_submesh();
auto* buffer = mesh->submesh(smi);
for(auto i = 0; i <= stacks; ++i) {
for(auto j = 0; j <= segments; ++j) {
float x0 = radius * cosf(delta_angle * j);
float z0 = radius * sinf(delta_angle * j);
kglt::Vec3 new_point(x0, delta_height * i, z0);
kglt::Vec3 new_normal = kglt::Vec3(x0, 0, z0).normalized();
kglt::Vec2 new_uv = kglt::Vec2(j / (float) segments, i / (float) stacks);
mesh->shared_data().position(new_point);
mesh->shared_data().diffuse(kglt::Colour::WHITE);
mesh->shared_data().normal(new_normal);
mesh->shared_data().tex_coord0(new_uv);
mesh->shared_data().move_next();
if(i != stacks) {
buffer->index_data().index(offset + segments + 1);
buffer->index_data().index(offset);
buffer->index_data().index(offset + segments);
buffer->index_data().index(offset + segments + 1);
buffer->index_data().index(offset + 1);
buffer->index_data().index(offset);
}
++offset;
}
}
// Now cap the cylinder
auto center_index = offset;
// Add a central point at the base
mesh->shared_data().position(kglt::Vec3());
mesh->shared_data().normal(kglt::Vec3(0, -1, 0));
mesh->shared_data().tex_coord0(kglt::Vec2());
mesh->shared_data().move_next();
++offset;
for(auto j = 0; j <= segments; ++j) {
float x0 = cosf(j * delta_angle);
float z0 = sinf(j * delta_angle);
kglt::Vec3 new_point(x0 * radius, 0, z0 * radius);
kglt::Vec3 new_normal(0, -1, 0);
kglt::Vec2 new_uv(x0, z0);
mesh->shared_data().position(new_point);
mesh->shared_data().normal(new_normal);
mesh->shared_data().tex_coord0(new_uv);
mesh->shared_data().move_next();
if(j != segments) {
buffer->index_data().index(center_index);
buffer->index_data().index(offset);
buffer->index_data().index(offset + 1);
}
}
center_index = offset;
// Add a central point at the top
mesh->shared_data().position(kglt::Vec3(0, length, 0));
mesh->shared_data().normal(kglt::Vec3(0, 1, 0));
mesh->shared_data().tex_coord0(kglt::Vec2());
mesh->shared_data().move_next();
++offset;
for(auto j = 0; j <= segments; ++j) {
float x0 = cosf(j * delta_angle);
float z0 = sinf(j * delta_angle);
kglt::Vec3 new_point(x0 * radius, length, z0 * radius);
kglt::Vec3 new_normal(0, 1, 0);
kglt::Vec2 new_uv(x0, z0);
mesh->shared_data().position(new_point);
mesh->shared_data().normal(new_normal);
mesh->shared_data().tex_coord0(new_uv);
mesh->shared_data().move_next();
if(j != segments) {
buffer->index_data().index(center_index);
buffer->index_data().index(offset + 1);
buffer->index_data().index(offset);
}
}
mesh->shared_data().done();
buffer->index_data().done();
}
