[Bf-blender-cvs] [0f85174] master: Fix occasional wrong normal for curves with minimum width.
Brecht Van Lommel
noreply at git.blender.org
Wed Apr 23 01:40:57 CEST 2014
Commit: 0f85174d503535287bd5844620cfd22dfecd373e
Author: Brecht Van Lommel
Date: Tue Apr 22 23:47:19 2014 +0200
https://developer.blender.org/rB0f85174d503535287bd5844620cfd22dfecd373e
Fix occasional wrong normal for curves with minimum width.
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.
===================================================================
M intern/cycles/kernel/geom/geom_curve.h
M intern/cycles/kernel/svm/svm_closure.h
===================================================================
diff --git a/intern/cycles/kernel/geom/geom_curve.h b/intern/cycles/kernel/geom/geom_curve.h
index e57bcd8..57fa038 100644
--- a/intern/cycles/kernel/geom/geom_curve.h
+++ b/intern/cycles/kernel/geom/geom_curve.h
@@ -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) {
diff --git a/intern/cycles/kernel/svm/svm_closure.h b/intern/cycles/kernel/svm/svm_closure.h
index caae654..fe3fe697 100644
--- a/intern/cycles/kernel/svm/svm_closure.h
+++ b/intern/cycles/kernel/svm/svm_closure.h
@@ -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);
}
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