From 0f85174d503535287bd5844620cfd22dfecd373e Mon Sep 17 00:00:00 2001 From: Brecht Van Lommel Date: Tue, 22 Apr 2014 23:47:19 +0200 Subject: 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. --- intern/cycles/kernel/geom/geom_curve.h | 59 +++++++++++++++++++--------------- intern/cycles/kernel/svm/svm_closure.h | 8 ++++- 2 files changed, 40 insertions(+), 27 deletions(-) (limited to 'intern') diff --git a/intern/cycles/kernel/geom/geom_curve.h b/intern/cycles/kernel/geom/geom_curve.h index e57bcd894a6..57fa0388842 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 caae65487c4..fe3fe697bca 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); } -- cgit v1.2.3