static void merge_spheres(VECTOR C, DBL *r, VECTOR C1, DBL r1, VECTOR C2, DBL r2)
{
DBL l, r1r, r2r, k1, k2;
VECTOR D;
VSub(D, C1, C2);
VLength(l, D);
/* Check if one sphere encloses the other. */
r1r = sqrt(r1);
r2r = sqrt(r2);
if (l + r1r <= r2r)
{
Assign_Vector(C, C2);
*r = r2;
return;
}
if (l + r2r <= r1r)
{
Assign_Vector(C, C1);
*r = r1;
return;
}
k1 = (1.0 + (r1r - r2r) / l) / 2.0;
k2 = (1.0 + (r2r - r1r) / l) / 2.0;
VLinComb2(C, k1, C1, k2, C2);
*r = Sqr((l + r1r + r2r) / 2.0);
}
void Perturb_Normal(VECTOR Layer_Normal, const TNORMAL *Tnormal, const VECTOR EPoint, Intersection *Intersection, const Ray *ray, TraceThreadData *Thread)
{
VECTOR TPoint,P1;
DBL value1,value2,Amount;
int i;
BLEND_MAP *Blend_Map;
BLEND_MAP_ENTRY *Prev, *Cur;
if (Tnormal==NULL)
{
return;
}
/* If normal_map present, use it and return */
if ((Blend_Map=Tnormal->Blend_Map) != NULL)
{
if ((Blend_Map->Type == NORMAL_TYPE) && (Tnormal->Type == UV_MAP_PATTERN))
{
UV_VECT UV_Coords;
Cur = &(Tnormal->Blend_Map->Blend_Map_Entries[0]);
/* Don't bother warping, simply get the UV vect of the intersection */
Intersection->Object->UVCoord(UV_Coords, Intersection, Thread);
TPoint[X] = UV_Coords[U];
TPoint[Y] = UV_Coords[V];
TPoint[Z] = 0;
Perturb_Normal(Layer_Normal,Cur->Vals.Tnormal,TPoint,Intersection,ray,Thread);
VNormalizeEq(Layer_Normal);
Assign_Vector(Intersection->PNormal, Layer_Normal); /* -hdf- June 98 */
return;
}
else if ((Blend_Map->Type == NORMAL_TYPE) && (Tnormal->Type != AVERAGE_PATTERN))
{
/* NK 19 Nov 1999 added Warp_EPoint */
Warp_EPoint (TPoint, EPoint, (TPATTERN *)Tnormal);
value1 = Evaluate_TPat((TPATTERN *)Tnormal,TPoint,Intersection,ray,Thread);
Search_Blend_Map (value1,Blend_Map,&Prev,&Cur);
Warp_Normal(Layer_Normal,Layer_Normal, (TPATTERN *)Tnormal, Test_Flag(Tnormal,DONT_SCALE_BUMPS_FLAG));
Assign_Vector(P1,Layer_Normal);
Warp_EPoint (TPoint, EPoint, (TPATTERN *)Tnormal);
Perturb_Normal(Layer_Normal,Cur->Vals.Tnormal,TPoint,Intersection,ray,Thread);
if (Prev != Cur)
{
Perturb_Normal(P1,Prev->Vals.Tnormal,TPoint,Intersection,ray,Thread);
value2 = (value1-Prev->value)/(Cur->value-Prev->value);
value1 = 1.0-value2;
VLinComb2(Layer_Normal,value1,P1,value2,Layer_Normal);
}
UnWarp_Normal(Layer_Normal,Layer_Normal,(TPATTERN *)Tnormal, Test_Flag(Tnormal,DONT_SCALE_BUMPS_FLAG));
VNormalizeEq(Layer_Normal);
Assign_Vector(Intersection->PNormal, Layer_Normal); /* -hdf- June 98 */
return;
}
}
/* No normal_map. */
if (Tnormal->Type <= LAST_NORM_ONLY_PATTERN)
{
Warp_Normal(Layer_Normal,Layer_Normal, (TPATTERN *)Tnormal,
Test_Flag(Tnormal,DONT_SCALE_BUMPS_FLAG));
Warp_EPoint (TPoint, EPoint, (TPATTERN *)Tnormal);
switch (Tnormal->Type)
{
case BITMAP_PATTERN: bump_map (TPoint, Tnormal, Layer_Normal); break;
case BUMPS_PATTERN: bumps (TPoint, Tnormal, Layer_Normal); break;
case DENTS_PATTERN: dents (TPoint, Tnormal, Layer_Normal, Thread); break;
case RIPPLES_PATTERN: ripples (TPoint, Tnormal, Layer_Normal, Thread); break;
case WAVES_PATTERN: waves (TPoint, Tnormal, Layer_Normal, Thread); break;
case WRINKLES_PATTERN: wrinkles (TPoint, Tnormal, Layer_Normal); break;
case QUILTED_PATTERN: quilted (TPoint, Tnormal, Layer_Normal); break;
case FACETS_PATTERN: facets (TPoint, Tnormal, Layer_Normal, Thread); break;
case AVERAGE_PATTERN: Do_Average_Normals (TPoint, Tnormal, Layer_Normal, Intersection, ray, Thread); break;
default:
throw POV_EXCEPTION_STRING("Normal pattern not yet implemented.");
}
UnWarp_Normal(Layer_Normal,Layer_Normal, (TPATTERN *)Tnormal,
Test_Flag(Tnormal,DONT_SCALE_BUMPS_FLAG));
}
else
{
Warp_Normal(Layer_Normal,Layer_Normal, (TPATTERN *)Tnormal,
Test_Flag(Tnormal,DONT_SCALE_BUMPS_FLAG));
Amount=Tnormal->Amount * -5.0; /*fudge factor*/
Amount*=0.02/Tnormal->Delta; /* NK delta */
/* warp the center point first - this is the last warp */
Warp_EPoint(TPoint,EPoint,(TPATTERN *)Tnormal);
for(i=0; i<=3; i++)
{
VAddScaled(P1,TPoint,Tnormal->Delta,Pyramid_Vect[i]); /* NK delta */
value1 = Do_Slope_Map(Evaluate_TPat((TPATTERN *)Tnormal,P1,Intersection,ray,Thread),Blend_Map);
VAddScaledEq(Layer_Normal,value1*Amount,Pyramid_Vect[i]);
}
UnWarp_Normal(Layer_Normal,Layer_Normal,(TPATTERN *)Tnormal,
Test_Flag(Tnormal,DONT_SCALE_BUMPS_FLAG));
}
if ( Intersection )
Assign_Vector(Intersection->PNormal, Layer_Normal); /* -hdf- June 98 */
}
static DBL ground_fog(RAY *Ray, DBL Depth, DBL Width, FOG *Fog, COLOUR Colour)
{
DBL fog_density, delta;
DBL start, end;
DBL y1, y2, k;
VECTOR P, P1, P2;
/* Get start point. */
VEvaluateRay(P1, Ray->Initial, Depth, Ray->Direction);
/* Get end point. */
VLinComb2(P2, 1.0, P1, Width, Ray->Direction);
/*
* Could preform transfomation here to translate Start and End
* points into ground fog space.
*/
VDot(y1, P1, Fog->Up);
VDot(y2, P2, Fog->Up);
start = (y1 - Fog->Offset) / Fog->Alt;
end = (y2 - Fog->Offset) / Fog->Alt;
/* Get integral along y-axis from start to end. */
if (start <= 0.0)
{
if (end <= 0.0)
{
fog_density = 1.0;
}
else
{
fog_density = (atan(end) - start) / (end - start);
}
}
else
{
if (end <= 0.0)
{
fog_density = (atan(start) - end) / (start - end);
}
else
{
delta = start - end;
if (fabs(delta) > EPSILON)
{
fog_density = (atan(start) - atan(end)) / delta;
}
else
{
fog_density = 1.0 / (Sqr(start) + 1.0);
}
}
}
/* Apply turbulence. */
if (Fog->Turb != NULL)
{
VHalf(P, P1, P2);
VEvaluateEq(P, Fog->Turb->Turbulence);
/* The further away the less influence turbulence has. */
k = exp(-Width / Fog->Distance);
Width *= 1.0 - k * min(1.0, Turbulence(P, Fog->Turb, NULL)*Fog->Turb_Depth);
}
Assign_Colour(Colour, Fog->Colour);
return (exp(-Width * fog_density / Fog->Distance));
}
