public override bool ShadowHit(Ray ray, ref double tmin)
{
if (!shadows)
{
return(false);
}
Ray invRay = new Ray(MathUtils.TransformPoint(invMatrix, ray.O),
MathUtils.TransformDirection(invMatrix, ray.D));
return(obj.ShadowHit(invRay, ref tmin));
}
public override bool ShadowHit(Ray ray, ref double tmin)
{
if (!shadows || !bbox.Hit(ray))
{
return(false);
}
double ox = ray.O.X;
double oy = ray.O.Y;
double oz = ray.O.Z;
double dx = ray.D.X;
double dy = ray.D.Y;
double dz = ray.D.Z;
double x0 = bbox.x0;
double y0 = bbox.y0;
double z0 = bbox.z0;
double x1 = bbox.x0;
double y1 = bbox.y0;
double z1 = bbox.z0;
double txMin = 0, tyMin = 0, tzMin = 0;
double txMax = 0, tyMax = 0, tzMax = 0;
double a = 1.0 / dx;
if (a >= 0)
{
txMin = (x0 - ox) * a;
txMax = (x1 - ox) * a;
}
else
{
txMin = (x1 - ox) * a;
txMax = (x0 - ox) * a;
}
double b = 1.0 / dy;
if (b >= 0)
{
tyMin = (y0 - oy) * b;
tyMax = (y1 - oy) * b;
}
else
{
txMin = (y1 - oy) * b;
txMax = (y0 - oy) * b;
}
double c = 1.0 / dz;
if (c >= 0)
{
tzMin = (z0 - oz) * c;
tzMax = (z1 - oz) * c;
}
else
{
tzMin = (z1 - oz) * c;
tzMax = (z0 - oz) * c;
}
double t0, t1;
if (txMin > tyMin)
{
t0 = txMax;
}
else
{
t0 = tyMin;
}
if (tzMin > t0)
{
t0 = tzMin;
}
if (txMax < tyMax)
{
t1 = txMax;
}
else
{
t1 = tyMax;
}
if (tzMax < t1)
{
t1 = tzMax;
}
if (t0 > t1)
{
return(false);
}
int ix, iy, iz;
if (bbox.Inside(ray.O))
{
ix = (int)MathUtils.Clamp((ox - x0) * nx / (x1 - x0), 0, nx - 1);
iy = (int)MathUtils.Clamp((oy - y0) * ny / (y1 - y0), 0, ny - 1);
iz = (int)MathUtils.Clamp((oz - z0) * nz / (z1 - z0), 0, nz - 1);
}
else
{
Vec3 p = ray.HitPoint(t0);
ix = (int)MathUtils.Clamp((p.X - x0) * nx / (x1 - x0), 0, nx - 1);
iy = (int)MathUtils.Clamp((p.Y - y0) * ny / (y1 - y0), 0, ny - 1);
iz = (int)MathUtils.Clamp((p.Z - z0) * nz / (z1 - z0), 0, nz - 1);
}
double dtx = (txMax - txMin) / nx;
double dty = (tyMax - tyMin) / ny;
double dtz = (tzMax - tzMin) / nz;
double txNext, tyNext, tzNext;
int ixStep, iyStep, izStep;
int ixStop, iyStop, izStop;
if (dx > 0)
{
txNext = txMin + (ix + 1) * dtx;
ixStep = +1;
ixStop = nx;
}
else
{
txNext = txMin + (nx - ix) * dtx;
ixStep = -1;
ixStop = -1;
}
if (dx == 0.0)
{
txNext = MathUtils.HugeValue;
ixStep = -1;
ixStop = -1;
}
if (dy > 0)
{
tyNext = tyMin + (iy + 1) * dty;
iyStep = +1;
iyStop = ny;
}
else
{
tyNext = tyMin + (ny - iy) * dty;
iyStep = -1;
iyStop = -1;
}
if (dy == 0.0)
{
tyNext = MathUtils.HugeValue;
iyStep = -1;
iyStop = -1;
}
if (dz > 0)
{
tzNext = tzMin + (iz + 1) * dtz;
izStep = +1;
izStop = nz;
}
else
{
tzNext = tzMin + (nz - iz) * dtz;
izStep = -1;
izStop = -1;
}
if (dz == 0.0)
{
tzNext = MathUtils.HugeValue;
izStep = -1;
izStop = -1;
}
while (true)
{
GeometricObject obj = cells[ix + nx * iy + nx * ny * iz];
if (txNext < tyNext && txNext < tzNext)
{
if (obj != null && obj.ShadowHit(ray, ref tmin) && tmin < txNext)
{
material = obj.Material;
return(true);
}
txNext += dtx;
ix += ixStep;
if (ix == ixStop)
{
return(false);
}
}
else
{
if (tyNext < tzNext)
{
if (obj != null && obj.ShadowHit(ray, ref tmin) && tmin < tyNext)
{
material = obj.Material;
return(true);
}
tyNext += dty;
iy += iyStep;
if (iy == iyStop)
{
return(false);
}
}
else
{
if (obj != null && obj.ShadowHit(ray, ref tmin) && tmin < tzNext)
{
material = obj.Material;
return(true);
}
tzNext += dtz;
iz += izStep;
if (iz == izStop)
{
return(false);
}
}
}
}
}
public override bool ShadowHit(Ray ray, ref float tmin)
{
float t = float.MaxValue;
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);
}
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.ShadowHit(ray, ref t) && t < tmin)
{ //This part is different from hit function, Notice it!
tmin = t;
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.ShadowHit(ray, ref t) && t < tmin)
{
tmin = t;
return(true);
}
ty_next += dty;
iy += iy_step;
if (iy == iy_stop)
{
return(false);
}
}
else
{
if (object_ptr != null && object_ptr.ShadowHit(ray, ref t) && t < tmin)
{
tmin = t;
return(true);
}
tz_next += dtz;
iz += iz_step;
if (iz == iz_stop)
{
return(false);
}
}
}
}
}