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Cycles Hair: Fix of cardinal curve intersection routine

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Fixed some of my own mistakes in the cardinal curve intersection routine.
This commit is contained in:
Stuart Broadfoot
2013-01-21 00:58:14 +00:00
parent aaad394b7f
commit 4c67b23c8d
1 changed files with 53 additions and 51 deletions
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104
intern/cycles/kernel/kernel_bvh.h
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@@ -206,19 +206,19 @@ __device_inline void bvh_triangle_intersect(KernelGlobals *kg, Intersection *ise
} }
#ifdef __HAIR__ #ifdef __HAIR__
__device_inline void curvebounds(float *lower, float *lowert, float *upper, float *uppert, float p0, float p1, float p2, float p3) __device_inline void curvebounds(float *lower, float *upper, float *extremta, float *extrema, float *extremtb, float *extremb, float p0, float p1, float p2, float p3)
{ {
float halfdiscroot = (p2 * p2 - 3 * p3 * p1); float halfdiscroot = (p2 * p2 - 3 * p3 * p1);
float ta = -1.0f; float ta = -1.0f;
float tb = -1.0f; float tb = -1.0f;
*uppert = 0.0f; *extremta = -1.0f;
*extremtb = -1.0f;
*upper = p0; *upper = p0;
*lowert = 1.0f;
*lower = p0 + p1 + p2 + p3; *lower = p0 + p1 + p2 + p3;
*extrema = *upper;
*extremb = *lower;
if(*lower >= *upper) { if(*lower >= *upper) {
*uppert = 1.0f;
*upper = *lower; *upper = *lower;
*lowert = 0.0f;
*lower = p0; *lower = p0;
} }
@@ -233,27 +233,25 @@ __device_inline void curvebounds(float *lower, float *lowert, float *upper, floa
if(ta > 0.0f && ta < 1.0f) { if(ta > 0.0f && ta < 1.0f) {
t2 = ta * ta; t2 = ta * ta;
t3 = t2 * ta; t3 = t2 * ta;
float extrem = p3 * t3 + p2 * t2 + p1 * ta + p0; *extremta = ta;
if(extrem > *upper) { *extrema = p3 * t3 + p2 * t2 + p1 * ta + p0;
*upper = extrem; if(*extrema > *upper) {
*uppert = ta; *upper = *extrema;
} }
if(extrem < *lower) { if(*extrema < *lower) {
*lower = extrem; *lower = *extrema;
*lowert = ta;
} }
} }
if(tb > 0.0f && tb < 1.0f) { if(tb > 0.0f && tb < 1.0f) {
t2 = tb * tb; t2 = tb * tb;
t3 = t2 * tb; t3 = t2 * tb;
float extrem = p3 * t3 + p2 * t2 + p1 * tb + p0; *extremtb = tb;
if(extrem >= *upper) { *extremb = p3 * t3 + p2 * t2 + p1 * tb + p0;
*upper = extrem; if(*extremb >= *upper) {
*uppert = tb; *upper = *extremb;
} }
if(extrem <= *lower) { if(*extremb <= *lower) {
*lower = extrem; *lower = *extremb;
*lowert = tb;
} }
} }
} }
@@ -319,41 +317,34 @@ __device_inline void bvh_cardinal_curve_intersect(KernelGlobals *kg, Intersectio
float r_curr = max(r_st, r_en); float r_curr = max(r_st, r_en);
/*find bounds - this is slow for cubic curves*/ /*find bounds - this is slow for cubic curves*/
float xbound[4]; float upper,lower;
curvebounds(&xbound[0], &xbound[1], &xbound[2], &xbound[3], curve_coef[0].x, curve_coef[1].x, curve_coef[2].x, curve_coef[3].x); float xextrem[4];
if(xbound[0] > r_curr || xbound[2] < -r_curr) curvebounds(&lower, &upper, &xextrem[0], &xextrem[1], &xextrem[2], &xextrem[3], curve_coef[0].x, curve_coef[1].x, curve_coef[2].x, curve_coef[3].x);
if(lower > r_curr || upper < -r_curr)
return; return;
float ybound[4]; float yextrem[4];
curvebounds(&ybound[0], &ybound[1], &ybound[2], &ybound[3], curve_coef[0].y, curve_coef[1].y, curve_coef[2].y, curve_coef[3].y); curvebounds(&lower, &upper, &yextrem[0], &yextrem[1], &yextrem[2], &yextrem[3], curve_coef[0].y, curve_coef[1].y, curve_coef[2].y, curve_coef[3].y);
if(ybound[0] > r_curr || ybound[2] < -r_curr) if(lower > r_curr || upper < -r_curr)
return; return;
float zbound[4]; float zextrem[4];
curvebounds(&zbound[0], &zbound[1], &zbound[2], &zbound[3], curve_coef[0].z, curve_coef[1].z, curve_coef[2].z, curve_coef[3].z); curvebounds(&lower, &upper, &zextrem[0], &zextrem[1], &zextrem[2], &zextrem[3], curve_coef[0].z, curve_coef[1].z, curve_coef[2].z, curve_coef[3].z);
if(zbound[0] - r_curr > isect->t || zbound[2] + r_curr < 0.0f) if(lower - r_curr > isect->t || upper + r_curr < 0.0f)
return; return;
/*setup recurrent loop*/ /*setup recurrent loop*/
int level = 1 << depth; int level = 1 << depth;
int tree = 0; int tree = 0;
float resol = 0.5f / (float)level; float resol = 1.0f / (float)level;
int xmin = (int)(xbound[1] / resol);
int xmax = (int)(xbound[3] / resol);
int ymin = (int)(ybound[1] / resol);
int ymax = (int)(ybound[3] / resol);
int zmin = (int)(zbound[1] / resol);
int zmax = (int)(zbound[3] / resol);
/*begin loop*/ /*begin loop*/
while(!(tree >> (depth + 1))) { while(!(tree >> (depth))) {
float i_st = tree * resol; float i_st = tree * resol;
float i_en = i_st + (level * resol); float i_en = i_st + (level * resol);
float3 p_st = ((curve_coef[3] * i_st + curve_coef[2]) * i_st + curve_coef[1]) * i_st + curve_coef[0]; float3 p_st = ((curve_coef[3] * i_st + curve_coef[2]) * i_st + curve_coef[1]) * i_st + curve_coef[0];
float3 p_en = ((curve_coef[3] * i_en + curve_coef[2]) * i_en + curve_coef[1]) * i_en + curve_coef[0]; float3 p_en = ((curve_coef[3] * i_en + curve_coef[2]) * i_en + curve_coef[1]) * i_en + curve_coef[0];
float bminx = min(p_st.x, p_en.x); float bminx = min(p_st.x, p_en.x);
float bmaxx = max(p_st.x, p_en.x); float bmaxx = max(p_st.x, p_en.x);
float bminy = min(p_st.y, p_en.y); float bminy = min(p_st.y, p_en.y);
@@ -361,19 +352,30 @@ __device_inline void bvh_cardinal_curve_intersect(KernelGlobals *kg, Intersectio
float bminz = min(p_st.z, p_en.z); float bminz = min(p_st.z, p_en.z);
float bmaxz = max(p_st.z, p_en.z); float bmaxz = max(p_st.z, p_en.z);
if(tree == xmin) if(xextrem[0] >= i_st && xextrem[0] <= i_en) {
bminx = xbound[0]; bminx = min(bminx,xextrem[1]);
if(tree == xmax) bmaxx = max(bmaxx,xextrem[1]);
bmaxx = xbound[2]; }
if(tree == ymin) if(xextrem[2] >= i_st && xextrem[2] <= i_en) {
bminy = ybound[0]; bminx = min(bminx,xextrem[3]);
if(tree == ymax) bmaxx = max(bmaxx,xextrem[3]);
bmaxy = ybound[2]; }
if(tree == zmin) if(yextrem[0] >= i_st && yextrem[0] <= i_en) {
bminz = zbound[0]; bminy = min(bminy,yextrem[1]);
if(tree == zmax) bmaxy = max(bmaxy,yextrem[1]);
bmaxz = zbound[2]; }
if(yextrem[2] >= i_st && yextrem[2] <= i_en) {
bminy = min(bminy,yextrem[3]);
bmaxy = max(bmaxy,yextrem[3]);
}
if(zextrem[0] >= i_st && zextrem[0] <= i_en) {
bminz = min(bminz,zextrem[1]);
bmaxz = max(bmaxz,zextrem[1]);
}
if(zextrem[2] >= i_st && zextrem[2] <= i_en) {
bminz = min(bminz,zextrem[3]);
bmaxz = max(bmaxz,zextrem[3]);
}
float r1 = r_st + (r_en - r_st) * i_st; float r1 = r_st + (r_en - r_st) * i_st;
float r2 = r_st + (r_en - r_st) * i_en; float r2 = r_st + (r_en - r_st) * i_en;