Cycles: add Principled Hair BSDF.

This is a physically-based, easy-to-use shader for rendering hair and fur,
with controls for melanin, roughness and randomization.

Based on the paper "A Practical and Controllable Hair and Fur Model for
Production Path Tracing".

Implemented by Leonardo E. Segovia and Lukas Stockner, part of Google
Summer of Code 2018.

1 files changed, 0 insertions, 25 deletions

diff --git a/intern/cycles/kernel/geom/geom_curve_intersect.h b/intern/cycles/kernel/geom/geom_curve_intersect.h
index 46c3f408f0b..4cfbe21685c 100644
--- a/intern/cycles/kernel/geom/geom_curve_intersect.h
+++ b/intern/cycles/kernel/geom/geom_curve_intersect.h
@@ -752,31 +752,6 @@ ccl_device_forceinline bool curve_intersect(KernelGlobals *kg,
 #endif
 }
 
-ccl_device_inline float3 curvetangent(float t, float3 p0, float3 p1, float3 p2, float3 p3)
-{
-	float fc = 0.71f;
-	float data[4];
-	float t2 = t * t;
-	data[0] = -3.0f * fc          * t2  + 4.0f * fc * t                  - fc;
-	data[1] =  3.0f * (2.0f - fc) * t2  + 2.0f * (fc - 3.0f) * t;
-	data[2] =  3.0f * (fc - 2.0f) * t2  + 2.0f * (3.0f - 2.0f * fc) * t  + fc;
-	data[3] =  3.0f * fc          * t2  - 2.0f * fc * t;
-	return data[0] * p0 + data[1] * p1 + data[2] * p2 + data[3] * p3;
-}
-
-ccl_device_inline float3 curvepoint(float t, float3 p0, float3 p1, float3 p2, float3 p3)
-{
-	float data[4];
-	float fc = 0.71f;
-	float t2 = t * t;
-	float t3 = t2 * t;
-	data[0] = -fc          * t3  + 2.0f * fc          * t2 - fc * t;
-	data[1] =  (2.0f - fc) * t3  + (fc - 3.0f)        * t2 + 1.0f;
-	data[2] =  (fc - 2.0f) * t3  + (3.0f - 2.0f * fc) * t2 + fc * t;
-	data[3] =  fc          * t3  - fc * t2;
-	return data[0] * p0 + data[1] * p1 + data[2] * p2 + data[3] * p3;
-}
-
 ccl_device_inline float3 curve_refine(KernelGlobals *kg,
                                       ShaderData *sd,
                                       const Intersection *isect,