void sun_lightmap::add(sun_lightmap::rays& r, float raylen,
yaw_pitch dir2) const
{
const vector half(0.5, 0.5, 0.5);
for (int d(0); d < 6; ++d) {
vector normal(dir_vector[d]);
vector origin(half + normal * 0.6f);
vector dir(from_spherical(dir2.x, dir2.y));
float weight(dot_prod(dir, normal));
if (weight > 0)
r[d].add(voxel_raycast(origin, origin + dir * raylen), weight);
}
}
ambient_occlusion_lightmap::rays
ambient_occlusion_lightmap::precalc (float ambient_raylen, unsigned int count) const
{
rays result;
vector center (0.5f, 0.5f, 0.5f);
for (auto v : golden_spiral(count))
{
for (int i (0); i < 5; ++i)
{
vector normal (dir_vector[i]);
// Weight is calculated according to Lambert's cosine law:
// intensity = cos theta = a . b (for unit vectors)
float weight (dot_prod(v, normal));
if (weight <= 0)
continue;
// The ray's origin is set to somewhat above the center of the
// surface. (Not too close: this darkens corners too much.)
auto origin (center + normal * 0.8f);
auto dir (v * ambient_raylen);
result[i].add(voxel_raycast(origin, origin + dir), weight);
}
}
float max (0);
for (int i(0); i < 5; ++i)
{
if (result[i].weight > max)
max = result[i].weight;
}
max = 1.0f / max;
for (int i(0); i < 5; ++i)
result[i].multiply_weight(max);
return result;
}
