Cycles: Improved robustness of hair motion blur.motion_curve_fix

In some instances, the number of control vertices of a hair could change mid-frame.
Cycles would then be unable to calculate proper motion blur for those hairs. This adds
interpolated CVs to fill in for the missing data. While this will not necessarily result in
a fully accurate reconstruction of the guide hair, it preserves motion blur instead of disabling it.

Reviewers: #cycles, sergey

Reviewed By: #cycles, sergey

Subscribers: sergey, brecht, #cycles

Tags: #cycles

Differential Revision: https://developer.blender.org/D3695

18 files changed, 26 insertions, 26 deletions

diff --git a/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h b/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h
index ff238b7a834..4e7425bd800 100644
--- a/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h
+++ b/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h
@@ -232,4 +232,4 @@ ccl_device int bsdf_ashikhmin_shirley_sample(const ShaderClosure *sc, float3 Ng,
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_ASHIKHMIN_SHIRLEY_H__ */
+#endif  /* __BSDF_ASHIKHMIN_SHIRLEY_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_ashikhmin_velvet.h b/intern/cycles/kernel/closure/bsdf_ashikhmin_velvet.h
index b0bdea723b9..80fd9ba2b37 100644
--- a/intern/cycles/kernel/closure/bsdf_ashikhmin_velvet.h
+++ b/intern/cycles/kernel/closure/bsdf_ashikhmin_velvet.h
@@ -158,4 +158,4 @@ ccl_device int bsdf_ashikhmin_velvet_sample(const ShaderClosure *sc, float3 Ng,
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_ASHIKHMIN_VELVET_H__ */
+#endif  /* __BSDF_ASHIKHMIN_VELVET_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_diffuse.h b/intern/cycles/kernel/closure/bsdf_diffuse.h
index ee6d4cdf2df..946c460a70e 100644
--- a/intern/cycles/kernel/closure/bsdf_diffuse.h
+++ b/intern/cycles/kernel/closure/bsdf_diffuse.h
@@ -139,4 +139,4 @@ ccl_device int bsdf_translucent_sample(const ShaderClosure *sc, float3 Ng, float
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_DIFFUSE_H__ */
+#endif  /* __BSDF_DIFFUSE_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_diffuse_ramp.h b/intern/cycles/kernel/closure/bsdf_diffuse_ramp.h
index 35bb2fdf0e8..ca33a5b275c 100644
--- a/intern/cycles/kernel/closure/bsdf_diffuse_ramp.h
+++ b/intern/cycles/kernel/closure/bsdf_diffuse_ramp.h
@@ -103,8 +103,8 @@ ccl_device int bsdf_diffuse_ramp_sample(const ShaderClosure *sc, float3 Ng, floa
 	return LABEL_REFLECT|LABEL_DIFFUSE;
 }
 
-#endif /* __OSL__ */
+#endif  /* __OSL__ */
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_DIFFUSE_RAMP_H__ */
+#endif  /* __BSDF_DIFFUSE_RAMP_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_hair.h b/intern/cycles/kernel/closure/bsdf_hair.h
index 7b44a23f05b..e1a0cfaa3f5 100644
--- a/intern/cycles/kernel/closure/bsdf_hair.h
+++ b/intern/cycles/kernel/closure/bsdf_hair.h
@@ -277,4 +277,4 @@ ccl_device int bsdf_hair_transmission_sample(const ShaderClosure *sc, float3 Ng,
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_HAIR_H__ */
+#endif  /* __BSDF_HAIR_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_hair_principled.h b/intern/cycles/kernel/closure/bsdf_hair_principled.h
index b3b56be39ff..68335ee887a 100644
--- a/intern/cycles/kernel/closure/bsdf_hair_principled.h
+++ b/intern/cycles/kernel/closure/bsdf_hair_principled.h
@@ -229,7 +229,7 @@ ccl_device int bsdf_principled_hair_setup(ShaderData *sd, PrincipledHairBSDF *bs
 	return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_NEEDS_LCG;
 }
 
-#endif /* __HAIR__ */
+#endif  /* __HAIR__ */
 
 /* Given the Fresnel term and transmittance, generate the attenuation terms for each bounce. */
 ccl_device_inline void hair_attenuation(KernelGlobals *kg,
@@ -296,7 +296,7 @@ ccl_device float3 bsdf_principled_hair_eval(KernelGlobals *kg,
 	float3 Y = float4_to_float3(bsdf->extra->geom);
 
 	float3 X = safe_normalize(sd->dPdu);
-	kernel_assert(fabsf(dot(X, Y)) < 1e-4f);
+	kernel_assert(fabsf(dot(X, Y)) < 1e-3f);
 	float3 Z = safe_normalize(cross(X, Y));
 
 	float3 wo = make_float3(dot(sd->I, X), dot(sd->I, Y), dot(sd->I, Z));
@@ -378,7 +378,7 @@ ccl_device int bsdf_principled_hair_sample(KernelGlobals *kg,
 	float3 Y = float4_to_float3(bsdf->extra->geom);
 
 	float3 X = safe_normalize(sd->dPdu);
-	kernel_assert(fabsf(dot(X, Y)) < 1e-4f);
+	kernel_assert(fabsf(dot(X, Y)) < 1e-3f);
 	float3 Z = safe_normalize(cross(X, Y));
 
 	float3 wo = make_float3(dot(sd->I, X), dot(sd->I, Y), dot(sd->I, Z));
@@ -499,4 +499,4 @@ ccl_device void bsdf_principled_hair_blur(ShaderClosure *sc, float roughness)
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_HAIR_PRINCIPLED_H__ */
+#endif  /* __BSDF_HAIR_PRINCIPLED_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_microfacet.h b/intern/cycles/kernel/closure/bsdf_microfacet.h
index e74d5ebaa42..32b6e50b09a 100644
--- a/intern/cycles/kernel/closure/bsdf_microfacet.h
+++ b/intern/cycles/kernel/closure/bsdf_microfacet.h
@@ -1124,4 +1124,4 @@ ccl_device int bsdf_microfacet_beckmann_sample(KernelGlobals *kg, const ShaderCl
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_MICROFACET_H__ */
+#endif  /* __BSDF_MICROFACET_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h b/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h
index e73915dbda7..5d300ef6db5 100644
--- a/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h
+++ b/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h
@@ -76,7 +76,7 @@ ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_eval)(
 		eval *= -lambda_r / (shadowing_lambda - lambda_r);
 	else
 		eval *= -lambda_r * beta(-lambda_r, shadowing_lambda+1.0f);
-#else /* MF_MULTI_GLOSSY */
+#else  /* MF_MULTI_GLOSSY */
 	const float G2 = 1.0f / (1.0f - (lambda_r + 1.0f) + shadowing_lambda);
 	float val = G2 * 0.25f / wi.z;
 	if(alpha.x == alpha.y)
@@ -129,7 +129,7 @@ ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_eval)(
 				phase = mf_eval_phase_glass(wr, lambda_r,  wo,  wo_outside, alpha, eta);
 			else
 				phase = mf_eval_phase_glass(wr, lambda_r, -wo, !wo_outside, alpha, 1.0f/eta);
-#else /* MF_MULTI_GLOSSY */
+#else  /* MF_MULTI_GLOSSY */
 			phase = mf_eval_phase_glossy(wr, lambda_r, wo, alpha) * throughput;
 #endif
 			eval += throughput * phase * mf_G1(wo_outside? wo: -wo, mf_C1((outside == wo_outside)? hr: -hr), shadowing_lambda);
@@ -153,7 +153,7 @@ ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_eval)(
 			else if(use_fresnel && order > 0) {
 				throughput *= interpolate_fresnel_color(wi_prev, wm, eta, F0, cspec0);
 			}
-#else /* MF_MULTI_GLOSSY */
+#else  /* MF_MULTI_GLOSSY */
 			if(use_fresnel && order > 0) {
 				throughput *= interpolate_fresnel_color(-wr, wm, eta, F0, cspec0);
 			}
@@ -248,7 +248,7 @@ ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_sample)(
 					throughput *= t_color;
 			}
 		}
-#else /* MF_MULTI_GLOSSY */
+#else  /* MF_MULTI_GLOSSY */
 		if(use_fresnel) {
 			float3 t_color = interpolate_fresnel_color(-wr, wm, eta, F0, cspec0);
 
diff --git a/intern/cycles/kernel/closure/bsdf_oren_nayar.h b/intern/cycles/kernel/closure/bsdf_oren_nayar.h
index 6b770fc0c16..3446d1609d9 100644
--- a/intern/cycles/kernel/closure/bsdf_oren_nayar.h
+++ b/intern/cycles/kernel/closure/bsdf_oren_nayar.h
@@ -108,4 +108,4 @@ ccl_device int bsdf_oren_nayar_sample(const ShaderClosure *sc, float3 Ng, float3
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_OREN_NAYAR_H__ */
+#endif  /* __BSDF_OREN_NAYAR_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_phong_ramp.h b/intern/cycles/kernel/closure/bsdf_phong_ramp.h
index 91c7803346d..83da05ac435 100644
--- a/intern/cycles/kernel/closure/bsdf_phong_ramp.h
+++ b/intern/cycles/kernel/closure/bsdf_phong_ramp.h
@@ -135,8 +135,8 @@ ccl_device int bsdf_phong_ramp_sample(const ShaderClosure *sc, float3 Ng, float3
 	return LABEL_REFLECT|LABEL_GLOSSY;
 }
 
-#endif /* __OSL__ */
+#endif  /* __OSL__ */
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_PHONG_RAMP_H__ */
+#endif  /* __BSDF_PHONG_RAMP_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_principled_diffuse.h b/intern/cycles/kernel/closure/bsdf_principled_diffuse.h
index 83be2b35a00..2f65fd54be2 100644
--- a/intern/cycles/kernel/closure/bsdf_principled_diffuse.h
+++ b/intern/cycles/kernel/closure/bsdf_principled_diffuse.h
@@ -122,4 +122,4 @@ ccl_device int bsdf_principled_diffuse_sample(const ShaderClosure *sc,
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_PRINCIPLED_DIFFUSE_H__ */
+#endif  /* __BSDF_PRINCIPLED_DIFFUSE_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_principled_sheen.h b/intern/cycles/kernel/closure/bsdf_principled_sheen.h
index 8b7c4399516..ccdcb1babd2 100644
--- a/intern/cycles/kernel/closure/bsdf_principled_sheen.h
+++ b/intern/cycles/kernel/closure/bsdf_principled_sheen.h
@@ -108,4 +108,4 @@ ccl_device int bsdf_principled_sheen_sample(const ShaderClosure *sc,
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_PRINCIPLED_SHEEN_H__ */
+#endif  /* __BSDF_PRINCIPLED_SHEEN_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_reflection.h b/intern/cycles/kernel/closure/bsdf_reflection.h
index b33b6e3597b..94f1c283af7 100644
--- a/intern/cycles/kernel/closure/bsdf_reflection.h
+++ b/intern/cycles/kernel/closure/bsdf_reflection.h
@@ -77,4 +77,4 @@ ccl_device int bsdf_reflection_sample(const ShaderClosure *sc, float3 Ng, float3
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_REFLECTION_H__ */
+#endif  /* __BSDF_REFLECTION_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_refraction.h b/intern/cycles/kernel/closure/bsdf_refraction.h
index b181650e928..abdd01c7a1d 100644
--- a/intern/cycles/kernel/closure/bsdf_refraction.h
+++ b/intern/cycles/kernel/closure/bsdf_refraction.h
@@ -86,4 +86,4 @@ ccl_device int bsdf_refraction_sample(const ShaderClosure *sc, float3 Ng, float3
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_REFRACTION_H__ */
+#endif  /* __BSDF_REFRACTION_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_toon.h b/intern/cycles/kernel/closure/bsdf_toon.h
index 6d8074b7130..097a56f22eb 100644
--- a/intern/cycles/kernel/closure/bsdf_toon.h
+++ b/intern/cycles/kernel/closure/bsdf_toon.h
@@ -215,4 +215,4 @@ ccl_device int bsdf_glossy_toon_sample(const ShaderClosure *sc, float3 Ng, float
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_TOON_H__ */
+#endif  /* __BSDF_TOON_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_transparent.h b/intern/cycles/kernel/closure/bsdf_transparent.h
index f788dbcd0ff..060dff69f52 100644
--- a/intern/cycles/kernel/closure/bsdf_transparent.h
+++ b/intern/cycles/kernel/closure/bsdf_transparent.h
@@ -106,4 +106,4 @@ ccl_device int bsdf_transparent_sample(const ShaderClosure *sc, float3 Ng, float
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_TRANSPARENT_H__ */
+#endif  /* __BSDF_TRANSPARENT_H__ */
diff --git a/intern/cycles/kernel/closure/bsdf_util.h b/intern/cycles/kernel/closure/bsdf_util.h
index b080e025d16..4f3453675c7 100644
--- a/intern/cycles/kernel/closure/bsdf_util.h
+++ b/intern/cycles/kernel/closure/bsdf_util.h
@@ -158,4 +158,4 @@ ccl_device_forceinline float3 interpolate_fresnel_color(float3 L, float3 H, floa
 
 CCL_NAMESPACE_END
 
-#endif /* __BSDF_UTIL_H__ */
+#endif  /* __BSDF_UTIL_H__ */
diff --git a/intern/cycles/kernel/closure/bssrdf.h b/intern/cycles/kernel/closure/bssrdf.h
index ba0c6ae8c61..98c7f23c288 100644
--- a/intern/cycles/kernel/closure/bssrdf.h
+++ b/intern/cycles/kernel/closure/bssrdf.h
@@ -499,4 +499,4 @@ ccl_device_forceinline float bssrdf_pdf(const ShaderClosure *sc, float r)
 
 CCL_NAMESPACE_END
 
-#endif /* __KERNEL_BSSRDF_H__ */
+#endif  /* __KERNEL_BSSRDF_H__ */