public override bool Hit(Ray ray, ref float t, ref ShadeRec sr)
{
float ox = ray.Position.X;
float oy = ray.Position.Y;
float oz = ray.Position.Z;
float dx = ray.Direction.X;
float dy = ray.Direction.Y;
float dz = ray.Direction.Z;
float x0 = bbox.Min.X;
float y0 = bbox.Min.Y;
float z0 = bbox.Min.Z;
float x1 = bbox.Max.X;
float y1 = bbox.Max.Y;
float z1 = bbox.Max.Z;
float tx_min, ty_min, tz_min;
float tx_max, ty_max, tz_max;
float a = 1.0f / dx;
if (a >= 0)
{
tx_min = (x0 - ox) * a;
tx_max = (x1 - ox) * a;
}
else
{
tx_min = (x1 - ox) * a;
tx_max = (x0 - ox) * a;
}
float b = 1.0f / dy;
if (b >= 0)
{
ty_min = (y0 - oy) * b;
ty_max = (y1 - oy) * b;
}
else
{
ty_min = (y1 - oy) * b;
ty_max = (y0 - oy) * b;
}
float c = 1.0f / dz;
if (c >= 0)
{
tz_min = (z0 - oz) * c;
tz_max = (z1 - oz) * c;
}
else
{
tz_min = (z1 - oz) * c;
tz_max = (z0 - oz) * c;
}
float t0, t1;
if (tx_min > ty_min)
{
t0 = tx_min;
}
else
{
t0 = ty_min;
}
if (tz_min > t0)
{
t0 = tz_min;
}
if (tx_max < ty_max)
{
t1 = tx_max;
}
else
{
t1 = ty_max;
}
if (tz_max < t1)
{
t1 = tz_max;
}
if (t0 > t1)
{
return(false);
}
else
{
Console.WriteLine("wtf");
}
int ix, iy, iz;
if (bbox.Inside(ray.Position))
{ // does the ray start inside the grid?
ix = clamp((ox - x0) * nx / (x1 - x0), 0, nx - 1);
iy = clamp((oy - y0) * ny / (y1 - y0), 0, ny - 1);
iz = clamp((oz - z0) * nz / (z1 - z0), 0, nz - 1);
}
else
{
Vector3 p = ray.Position + t0 * ray.Direction; // initial hit point with grid's bounding box
ix = clamp((p.X - x0) * nx / (x1 - x0), 0, nx - 1);
iy = clamp((p.Y - y0) * ny / (y1 - y0), 0, ny - 1);
iz = clamp((p.Z - z0) * nz / (z1 - z0), 0, nz - 1);
}
float dtx = (tx_max - tx_min) / nx;
float dty = (ty_max - ty_min) / ny;
float dtz = (tz_max - tz_min) / nz;
float tx_next, ty_next, tz_next;
int ix_step, iy_step, iz_step;
int ix_stop, iy_stop, iz_stop;
if (dx > 0)
{
tx_next = tx_min + (ix + 1) * dtx;
ix_step = +1;
ix_stop = nx;
}
else
{
tx_next = tx_min + (nx - ix) * dtx;
ix_step = -1;
ix_stop = -1;
}
if (dx == 0.0)
{
tx_next = float.MaxValue;
ix_step = -1;
ix_stop = -1;
}
if (dy > 0)
{
ty_next = ty_min + (iy + 1) * dty;
iy_step = +1;
iy_stop = ny;
}
else
{
ty_next = ty_min + (ny - iy) * dty;
iy_step = -1;
iy_stop = -1;
}
if (dy == 0.0)
{
ty_next = float.MaxValue;
iy_step = -1;
iy_stop = -1;
}
if (dz > 0)
{
tz_next = tz_min + (iz + 1) * dtz;
iz_step = +1;
iz_stop = nz;
}
else
{
tz_next = tz_min + (nz - iz) * dtz;
iz_step = -1;
iz_stop = -1;
}
if (dz == 0.0)
{
tz_next = float.MaxValue;
iz_step = -1;
iz_stop = -1;
}
while (true)
{
GeometricObject object_ptr = cells[ix + nx * iy + nx * ny * iz];
if (tx_next < ty_next && tx_next < tz_next)
{
if (object_ptr != null && object_ptr.Hit(ray, ref t, ref sr) && t < tx_next)
{
Material = object_ptr.GetMaterial();
return(true);
}
tx_next += dtx;
ix += ix_step;
if (ix == ix_stop)
{
return(false);
}
}
else
{
if (ty_next < tz_next)
{
if (object_ptr != null && object_ptr.Hit(ray, ref t, ref sr) && t < ty_next)
{
Material = object_ptr.GetMaterial();
return(true);
}
ty_next += dty;
iy += iy_step;
if (iy == iy_stop)
{
return(false);
}
}
else
{
if (object_ptr != null && object_ptr.Hit(ray, ref t, ref sr) && t < tz_next)
{
Material = object_ptr.GetMaterial();
return(true);
}
tz_next += dtz;
iz += iz_step;
if (iz == iz_stop)
{
return(false);
}
}
}
}
}
public void SetObject(GeometricObject obj)
{
Object = obj;
Material = Object.GetMaterial();
}