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Fix occasional wrong normal for curves with minimum width.

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This caused a couple of fireflies in koro_final.blend. The wrong normal would
cause the shading point to be set as backfacing, which triggered another bug
with hair BSDFs on the backface of hair curves. That one is not fixed yet but
there's a comment in the code about it now.
This commit is contained in:
Brecht Van Lommel
2014-04-22 23:47:19 +02:00
parent f2c483d108
commit 0f85174d50
2 changed files with 40 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
intern/cycles/kernel/geom/geom_curve.h
View File

@@ -438,6 +438,8 @@ ccl_device_inline bool bvh_cardinal_curve_intersect(KernelGlobals *kg, Intersect
* dP* is reversed if necessary.*/
float t = isect->t;
float u = 0.0f;
float gd = 0.0f;
if(flags & CURVE_KN_RIBBONS) {
float3 tg = (p_en - p_st);
float w = tg.x * tg.x + tg.y * tg.y;
@@ -508,7 +510,7 @@ ccl_device_inline bool bvh_cardinal_curve_intersect(KernelGlobals *kg, Intersect
}
/* --- */
float3 tg = (p_en - p_st) / l;
float gd = (or2 - or1) / l;
gd = (or2 - or1) / l;
float difz = -dot(p_st,tg);
float cyla = 1.0f - (tg.z * tg.z * (1 + gd*gd));
float halfb = (-p_st.z - tg.z*(difz + gd*(difz*gd + or1)));
@@ -576,8 +578,8 @@ ccl_device_inline bool bvh_cardinal_curve_intersect(KernelGlobals *kg, Intersect
isect->object = object;
isect->type = type;
isect->u = u;
isect->v = 0.0f;
/*isect->v = 1.0f - coverage; */
isect->v = gd;
/*isect->transparency = 1.0f - coverage; */
isect->t = t;
hit = true;
}
@@ -812,13 +814,10 @@ ccl_device_inline bool bvh_curve_intersect(KernelGlobals *kg, Intersection *isec
isect->object = object;
isect->type = type;
isect->u = z*invl;
isect->v = td/(4*a*a);
/*isect->v = 1.0f - adjradius;*/
isect->v = gd;
/*isect->transparency = 1.0f - adjradius;*/
isect->t = t;
if(backface)
isect->u = -isect->u;
return true;
}
}
@@ -901,35 +900,41 @@ ccl_device_inline float3 bvh_curve_refine(KernelGlobals *kg, ShaderData *sd, con
motion_cardinal_curve_keys(kg, sd->object, sd->prim, sd->time, ka, k0, k1, kb, P_curve);
}
float l = 1.0f;
tg = normalize_len(float4_to_float3(P_curve[2] - P_curve[1]), &l);
float r1 = P_curve[1].w;
float r2 = P_curve[2].w;
float gd = ((r2 - r1)/l);
P = P + D*t;
float3 p[4];
p[0] = float4_to_float3(P_curve[0]);
p[1] = float4_to_float3(P_curve[1]);
p[2] = float4_to_float3(P_curve[2]);
p[3] = float4_to_float3(P_curve[3]);
P = P + D*t;
#ifdef __UV__
sd->u = isect->u;
sd->v = 0.0f;
#endif
tg = normalize(curvetangent(isect->u, p[0], p[1], p[2], p[3]));
if(kernel_data.curve.curveflags & CURVE_KN_RIBBONS)
if(kernel_data.curve.curveflags & CURVE_KN_RIBBONS) {
tg = normalize(curvetangent(isect->u, p[0], p[1], p[2], p[3]));
sd->Ng = normalize(-(D - tg * (dot(tg, D))));
}
else {
/* direction from inside to surface of curve */
float3 p_curr = curvepoint(isect->u, p[0], p[1], p[2], p[3]);
sd->Ng = normalize(P - p_curr);
sd->Ng = sd->Ng - gd * tg;
sd->Ng = normalize(sd->Ng);
/* adjustment for changing radius */
float gd = isect->v;
if(gd != 0.0f) {
tg = normalize(curvetangent(isect->u, p[0], p[1], p[2], p[3]));
sd->Ng = sd->Ng - gd * tg;
sd->Ng = normalize(sd->Ng);
}
}
/* todo: sometimes the normal is still so that this is detected as
* backfacing even if cull backfaces is enabled */
sd->N = sd->Ng;
}
else {
@@ -945,9 +950,6 @@ ccl_device_inline float3 bvh_curve_refine(KernelGlobals *kg, ShaderData *sd, con
float l = 1.0f;
tg = normalize_len(float4_to_float3(P_curve[1] - P_curve[0]), &l);
float r1 = P_curve[0].w;
float r2 = P_curve[1].w;
float gd = ((r2 - r1)/l);
P = P + D*t;
@@ -963,9 +965,14 @@ ccl_device_inline float3 bvh_curve_refine(KernelGlobals *kg, ShaderData *sd, con
sd->Ng = normalize(sd->Ng);
}
else {
float gd = isect->v;
/* direction from inside to surface of curve */
sd->Ng = (dif - tg * sd->u * l) / (P_curve[0].w + sd->u * l * gd);
/* adjustment for changing radius */
if (gd != 0.0f) {
sd->Ng = sd->Ng - gd * tg ;
sd->Ng = sd->Ng - gd * tg;
sd->Ng = normalize(sd->Ng);
}
}
@@ -980,7 +987,7 @@ ccl_device_inline float3 bvh_curve_refine(KernelGlobals *kg, ShaderData *sd, con
#endif
/*add fading parameter for minimum pixel width with transparency bsdf*/
/*sd->curve_transparency = isect->v;*/
/*sd->curve_transparency = isect->transparency;*/
/*sd->curve_radius = sd->u * gd * l + r1;*/
if(isect->object != OBJECT_NONE) {

8
intern/cycles/kernel/svm/svm_closure.h
View File

@@ -336,8 +336,14 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
if(sd->flag & SD_BACKFACING && sd->type & PRIMITIVE_ALL_CURVE) {
ShaderClosure *sc = svm_node_closure_get_bsdf(sd, mix_weight);
if(sc) {
sc->weight = make_float3(1.0f,1.0f,1.0f);
/* todo: giving a fixed weight here will cause issues when
* mixing multiple BSDFS. energey will not be conserved and
* the throughput can blow up after multiple bounces. we
* better figure out a way to skip backfaces from rays
* spawned by transmission from the front */
sc->weight = make_float3(1.0f, 1.0f, 1.0f);
sc->N = N;
sd->flag |= bsdf_transparent_setup(sc);
}