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WIP: uv-simple-select #1

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Chris Blackbourn wants to merge 182 commits from uv-simple-select into main
pull from: uv-simple-select
merge into: Chris_Blackbourn:main

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Conversation 0 Commits 182 Files Changed 881 +246 -206
6 changed files with 246 additions and 206 deletions
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23
intern/cycles/kernel/closure/bsdf.h
View File

@ -276,6 +276,10 @@ ccl_device_inline void bsdf_roughness_eta(const KernelGlobals kg,
ccl_private float2 *roughness, ccl_private float2 *roughness,
ccl_private float *eta) ccl_private float *eta)
{ {
#ifdef __SVM__
bool refractive = false;
float alpha = 1.0f;
#endif
switch (sc->type) { switch (sc->type) {
case CLOSURE_BSDF_DIFFUSE_ID: case CLOSURE_BSDF_DIFFUSE_ID:
*roughness = one_float2(); *roughness = one_float2();
@ -287,13 +291,11 @@ ccl_device_inline void bsdf_roughness_eta(const KernelGlobals kg,
*eta = 1.0f; *eta = 1.0f;
break; break;
# ifdef __OSL__ # ifdef __OSL__
case CLOSURE_BSDF_PHONG_RAMP_ID: { case CLOSURE_BSDF_PHONG_RAMP_ID:
ccl_private const PhongRampBsdf *bsdf = (ccl_private const PhongRampBsdf *)sc; alpha = phong_ramp_exponent_to_roughness(((ccl_private const PhongRampBsdf *)sc)->exponent);
float alpha = phong_ramp_exponent_to_roughness(bsdf->exponent);
*roughness = make_float2(alpha, alpha); *roughness = make_float2(alpha, alpha);
*eta = 1.0f; *eta = 1.0f;
break; break;
}
case CLOSURE_BSDF_DIFFUSE_RAMP_ID: case CLOSURE_BSDF_DIFFUSE_RAMP_ID:
*roughness = one_float2(); *roughness = one_float2();
*eta = 1.0f; *eta = 1.0f;
@ -326,7 +328,7 @@ ccl_device_inline void bsdf_roughness_eta(const KernelGlobals kg,
case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID: { case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID: {
ccl_private const MicrofacetBsdf *bsdf = (ccl_private const MicrofacetBsdf *)sc; ccl_private const MicrofacetBsdf *bsdf = (ccl_private const MicrofacetBsdf *)sc;
*roughness = make_float2(bsdf->alpha_x, bsdf->alpha_y); *roughness = make_float2(bsdf->alpha_x, bsdf->alpha_y);
const bool refractive = bsdf->type == CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID; refractive = bsdf->type == CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID;
*eta = refractive ? 1.0f / bsdf->ior : bsdf->ior; *eta = refractive ? 1.0f / bsdf->ior : bsdf->ior;
break; break;
} }
@ -348,7 +350,7 @@ ccl_device_inline void bsdf_roughness_eta(const KernelGlobals kg,
case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID: { case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID: {
ccl_private const MicrofacetBsdf *bsdf = (ccl_private const MicrofacetBsdf *)sc; ccl_private const MicrofacetBsdf *bsdf = (ccl_private const MicrofacetBsdf *)sc;
*roughness = make_float2(bsdf->alpha_x, bsdf->alpha_y); *roughness = make_float2(bsdf->alpha_x, bsdf->alpha_y);
const bool refractive = bsdf->type == CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID; refractive = bsdf->type == CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID;
*eta = refractive ? 1.0f / bsdf->ior : bsdf->ior; *eta = refractive ? 1.0f / bsdf->ior : bsdf->ior;
} break; } break;
case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID: { case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID: {
@ -380,12 +382,11 @@ ccl_device_inline void bsdf_roughness_eta(const KernelGlobals kg,
((ccl_private HairBsdf *)sc)->roughness2); ((ccl_private HairBsdf *)sc)->roughness2);
*eta = 1.0f; *eta = 1.0f;
break; break;
case CLOSURE_BSDF_HAIR_PRINCIPLED_ID: { case CLOSURE_BSDF_HAIR_PRINCIPLED_ID:
ccl_private const PrincipledHairBSDF *bsdf = (ccl_private const PrincipledHairBSDF *)sc; alpha = ((ccl_private PrincipledHairBSDF *)sc)->m0_roughness;
*roughness = make_float2(bsdf->v_R, bsdf->v_R); *roughness = make_float2(alpha, alpha);
*eta = bsdf->eta; *eta = ((ccl_private PrincipledHairBSDF *)sc)->eta;
break; break;
}
case CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID: case CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID:
*roughness = one_float2(); *roughness = one_float2();
*eta = 1.0f; *eta = 1.0f;

405
intern/cycles/kernel/closure/bsdf_hair_principled.h
View File

@ -13,11 +13,7 @@ CCL_NAMESPACE_BEGIN
typedef struct PrincipledHairExtra { typedef struct PrincipledHairExtra {
/* Geometry data. */ /* Geometry data. */
float3 Y, Z; float4 geom;
float gamma_o, gamma_t;
/* Precomputed Transmission and Fresnel term */
Spectrum T;
float f;
} PrincipledHairExtra; } PrincipledHairExtra;
typedef struct PrincipledHairBSDF { typedef struct PrincipledHairBSDF {
@ -25,16 +21,16 @@ typedef struct PrincipledHairBSDF {
/* Absorption coefficient. */ /* Absorption coefficient. */
Spectrum sigma; Spectrum sigma;
/* Variance of the underlying logistic distribution, based on longitudinal roughness. */ /* Variance of the underlying logistic distribution. */
float v; float v;
/* Scale factor of the underlying logistic distribution, based on azimuthal roughness. */ /* Scale factor of the underlying logistic distribution. */
float s; float s;
/* Alternative value for v, used for the R lobe. */
float v_R;
/* Cuticle tilt angle. */ /* Cuticle tilt angle. */
float alpha; float alpha;
/* IOR. */ /* IOR. */
float eta; float eta;
/* Effective variance for the diffuse bounce only. */
float m0_roughness;
/* Extra closure. */ /* Extra closure. */
ccl_private PrincipledHairExtra *extra; ccl_private PrincipledHairExtra *extra;
@ -135,9 +131,6 @@ ccl_device_inline float sample_trimmed_logistic(float u, float s)
ccl_device_inline float azimuthal_scattering( ccl_device_inline float azimuthal_scattering(
float phi, int p, float s, float gamma_o, float gamma_t) float phi, int p, float s, float gamma_o, float gamma_t)
{ {
if (p == 3) {
return M_1_2PI_F;
}
float phi_o = wrap_angle(phi - delta_phi(p, gamma_o, gamma_t)); float phi_o = wrap_angle(phi - delta_phi(p, gamma_o, gamma_t));
float val = trimmed_logistic(phi_o, s); float val = trimmed_logistic(phi_o, s);
return val; return val;
@ -162,45 +155,27 @@ ccl_device_inline float longitudinal_scattering(
} }
} }
ccl_device_forceinline float hair_get_lobe_v(const ccl_private PrincipledHairBSDF *bsdf,
const int lobe)
{
if (lobe == 0) {
return bsdf->v_R;
}
else if (lobe == 1) {
return 0.25f * bsdf->v;
}
else {
return 4.0f * bsdf->v;
}
}
#ifdef __HAIR__ #ifdef __HAIR__
/* Set up the hair closure. */ /* Set up the hair closure. */
ccl_device int bsdf_principled_hair_setup(ccl_private ShaderData *sd, ccl_device int bsdf_principled_hair_setup(ccl_private ShaderData *sd,
ccl_private PrincipledHairBSDF *bsdf, ccl_private PrincipledHairBSDF *bsdf)
float u_rough,
float u_coat_rough,
float v_rough)
{ {
u_rough = clamp(u_rough, 0.001f, 1.0f);
v_rough = clamp(v_rough, 0.001f, 1.0f);
/* u_coat_rough is a multiplier that modifies u_rough for the R lobe. */
float u_R_roughness = clamp(u_coat_rough * u_rough, 0.001f, 1.0f);
bsdf->type = CLOSURE_BSDF_HAIR_PRINCIPLED_ID; bsdf->type = CLOSURE_BSDF_HAIR_PRINCIPLED_ID;
bsdf->v = clamp(bsdf->v, 0.001f, 1.0f);
bsdf->s = clamp(bsdf->s, 0.001f, 1.0f);
/* Apply Primary Reflection Roughness modifier. */
bsdf->m0_roughness = clamp(bsdf->m0_roughness * bsdf->v, 0.001f, 1.0f);
/* Map from the azimuthal and the two longitudinal roughnesses to variance and scale factor. */ /* Map from roughness_u and roughness_v to variance and scale factor. */
bsdf->v = sqr(0.726f * u_rough + 0.812f * sqr(u_rough) + 3.700f * pow20(u_rough)); bsdf->v = sqr(0.726f * bsdf->v + 0.812f * sqr(bsdf->v) + 3.700f * pow20(bsdf->v));
bsdf->v_R = sqr(0.726f * u_R_roughness + 0.812f * sqr(u_R_roughness) + bsdf->s = (0.265f * bsdf->s + 1.194f * sqr(bsdf->s) + 5.372f * pow22(bsdf->s)) * M_SQRT_PI_8_F;
3.700f * pow20(u_R_roughness)); bsdf->m0_roughness = sqr(0.726f * bsdf->m0_roughness + 0.812f * sqr(bsdf->m0_roughness) +
bsdf->s = (0.265f * v_rough + 1.194f * sqr(v_rough) + 5.372f * pow22(v_rough)) * M_SQRT_PI_8_F; 3.700f * pow20(bsdf->m0_roughness));
/* Compute local frame, aligned to curve tangent and ray direction. */ /* Compute local frame, aligned to curve tangent and ray direction. */
float3 X = safe_normalize(sd->dPdu); float3 X = safe_normalize(sd->dPdu);
bsdf->extra->Y = safe_normalize(cross(X, sd->wi)); float3 Y = safe_normalize(cross(X, sd->wi));
bsdf->extra->Z = safe_normalize(cross(X, bsdf->extra->Y)); float3 Z = safe_normalize(cross(X, Y));
/* h -1..0..1 means the rays goes from grazing the hair, to hitting it at /* h -1..0..1 means the rays goes from grazing the hair, to hitting it at
* the center, to grazing the other edge. This is the sine of the angle * the center, to grazing the other edge. This is the sine of the angle
@ -208,28 +183,13 @@ ccl_device int bsdf_principled_hair_setup(ccl_private ShaderData *sd,
/* TODO: we convert this value to a cosine later and discard the sign, so /* TODO: we convert this value to a cosine later and discard the sign, so
* we could probably save some operations. */ * we could probably save some operations. */
float h = (sd->type & PRIMITIVE_CURVE_RIBBON) ? -sd->v : dot(cross(sd->Ng, X), bsdf->extra->Z); float h = (sd->type & PRIMITIVE_CURVE_RIBBON) ? -sd->v : dot(cross(sd->Ng, X), Z);
kernel_assert(fabsf(h) < 1.0f + 1e-4f); kernel_assert(fabsf(h) < 1.0f + 1e-4f);
kernel_assert(isfinite_safe(Y)); kernel_assert(isfinite_safe(Y));
kernel_assert(isfinite_safe(h)); kernel_assert(isfinite_safe(h));
const float sin_theta_o = dot(sd->wi, X); bsdf->extra->geom = make_float4(Y.x, Y.y, Y.z, h);
const float cos_theta_o = cos_from_sin(sin_theta_o);
const float sin_theta_t = sin_theta_o / bsdf->eta;
const float cos_theta_t = cos_from_sin(sin_theta_t);
const float sin_gamma_o = h;
const float cos_gamma_o = cos_from_sin(sin_gamma_o);
bsdf->extra->gamma_o = safe_asinf(sin_gamma_o);
const float sin_gamma_t = sin_gamma_o * cos_theta_o / sqrtf(sqr(bsdf->eta) - sqr(sin_theta_o));
const float cos_gamma_t = cos_from_sin(sin_gamma_t);
bsdf->extra->gamma_t = safe_asinf(sin_gamma_t);
bsdf->extra->T = exp(-bsdf->sigma * (2.0f * cos_gamma_t / cos_theta_t));
bsdf->extra->f = fresnel_dielectric_cos(cos_theta_o * cos_gamma_o, bsdf->eta);
return SD_BSDF | SD_BSDF_HAS_EVAL | SD_BSDF_NEEDS_LCG | SD_BSDF_HAS_TRANSMISSION; return SD_BSDF | SD_BSDF_HAS_EVAL | SD_BSDF_NEEDS_LCG | SD_BSDF_HAS_TRANSMISSION;
} }
@ -238,35 +198,35 @@ ccl_device int bsdf_principled_hair_setup(ccl_private ShaderData *sd,
/* Given the Fresnel term and transmittance, generate the attenuation terms for each bounce. */ /* Given the Fresnel term and transmittance, generate the attenuation terms for each bounce. */
ccl_device_inline void hair_attenuation( ccl_device_inline void hair_attenuation(
KernelGlobals kg, float f, Spectrum T, ccl_private Spectrum *Ap, ccl_private float *lobe_pdf) KernelGlobals kg, float f, Spectrum T, ccl_private Spectrum *Ap, ccl_private float *Ap_energy)
{ {
/* Primary specular (R). */ /* Primary specular (R). */
Ap[0] = make_spectrum(f); Ap[0] = make_spectrum(f);
lobe_pdf[0] = f; Ap_energy[0] = f;
/* Transmission (TT). */ /* Transmission (TT). */
Spectrum col = sqr(1.0f - f) * T; Spectrum col = sqr(1.0f - f) * T;
Ap[1] = col; Ap[1] = col;
lobe_pdf[1] = spectrum_to_gray(kg, col); Ap_energy[1] = spectrum_to_gray(kg, col);
/* Secondary specular (TRT). */ /* Secondary specular (TRT). */
col *= T * f; col *= T * f;
Ap[2] = col; Ap[2] = col;
lobe_pdf[2] = spectrum_to_gray(kg, col); Ap_energy[2] = spectrum_to_gray(kg, col);
/* Residual component (TRRT+). */ /* Residual component (TRRT+). */
col *= safe_divide(T * f, one_spectrum() - T * f); col *= safe_divide(T * f, one_spectrum() - T * f);
Ap[3] = col; Ap[3] = col;
lobe_pdf[3] = spectrum_to_gray(kg, col); Ap_energy[3] = spectrum_to_gray(kg, col);
/* Normalize sampling weights. */ /* Normalize sampling weights. */
float totweight = lobe_pdf[0] + lobe_pdf[1] + lobe_pdf[2] + lobe_pdf[3]; float totweight = Ap_energy[0] + Ap_energy[1] + Ap_energy[2] + Ap_energy[3];
float fac = safe_divide(1.0f, totweight); float fac = safe_divide(1.0f, totweight);
lobe_pdf[0] *= fac; Ap_energy[0] *= fac;
lobe_pdf[1] *= fac; Ap_energy[1] *= fac;
lobe_pdf[2] *= fac; Ap_energy[2] *= fac;
lobe_pdf[3] *= fac; Ap_energy[3] *= fac;
} }
/* Given the tilt angle, generate the rotated theta_i for the different bounces. */ /* Given the tilt angle, generate the rotated theta_i for the different bounces. */
@ -288,120 +248,91 @@ ccl_device_inline void hair_alpha_angles(float sin_theta_i,
angles[3] = fabsf(cos_theta_i * cos_1alpha + sin_theta_i * sin_1alpha); angles[3] = fabsf(cos_theta_i * cos_1alpha + sin_theta_i * sin_1alpha);
angles[4] = sin_theta_i * cos_4alpha - cos_theta_i * sin_4alpha; angles[4] = sin_theta_i * cos_4alpha - cos_theta_i * sin_4alpha;
angles[5] = fabsf(cos_theta_i * cos_4alpha + sin_theta_i * sin_4alpha); angles[5] = fabsf(cos_theta_i * cos_4alpha + sin_theta_i * sin_4alpha);
angles[6] = sin_theta_i;
angles[7] = cos_theta_i;
}
/* Since most of the implementation is the same between sampling and evaluation,
* this shared function implements both.
* For evaluation, wo is an input, and randu/randv are ignored.
* For sampling, wo is an output, and randu/randv are used to pick it.
*/
template<bool do_sample>
ccl_device int bsdf_principled_hair_impl(KernelGlobals kg,
ccl_private const PrincipledHairBSDF *bsdf,
ccl_private ShaderData *sd,
ccl_private float3 *wo,
ccl_private Spectrum *F,
ccl_private float *pdf,
float randu,
float randv)
{
const float3 X = safe_normalize(sd->dPdu);
const float3 Y = bsdf->extra->Y;
const float3 Z = bsdf->extra->Z;
kernel_assert(fabsf(dot(X, Y)) < 1e-3f);
const float gamma_o = bsdf->extra->gamma_o;
const float gamma_t = bsdf->extra->gamma_t;
const float3 local_O = make_float3(dot(sd->wi, X), dot(sd->wi, Y), dot(sd->wi, Z));
const float sin_theta_o = local_O.x;
const float cos_theta_o = cos_from_sin(sin_theta_o);
const float phi_o = atan2f(local_O.z, local_O.y);
Spectrum Ap[4];
float lobe_pdf[4];
hair_attenuation(kg, bsdf->extra->f, bsdf->extra->T, Ap, lobe_pdf);
float sin_theta_i, cos_theta_i, phi;
int sampled_p = 0;
if (do_sample) {
/* Pick lobe for sampline */
for (; sampled_p < 3; sampled_p++) {
if (randu < lobe_pdf[sampled_p]) {
break;
}
randu -= lobe_pdf[sampled_p];
}
/* Sample incoming direction */
float v = hair_get_lobe_v(bsdf, sampled_p);
float randw = lcg_step_float(&sd->lcg_state), randx = lcg_step_float(&sd->lcg_state);
randw = max(randw, 1e-5f);
const float fac = 1.0f + v * logf(randw + (1.0f - randw) * expf(-2.0f / v));
sin_theta_i = -fac * sin_theta_o + cos_from_sin(fac) * cosf(M_2PI_F * randx) * cos_theta_o;
cos_theta_i = cos_from_sin(sin_theta_i);
if (sampled_p < 3) {
float angles[8];
hair_alpha_angles(sin_theta_i, cos_theta_i, -bsdf->alpha, angles);
sin_theta_i = angles[2 * sampled_p];
cos_theta_i = angles[2 * sampled_p + 1];
phi = delta_phi(sampled_p, gamma_o, gamma_t) + sample_trimmed_logistic(randv, bsdf->s);
}
else {
phi = M_2PI_F * randv;
}
const float phi_i = phi_o + phi;
*wo = X * sin_theta_i + Y * cos_theta_i * cosf(phi_i) + Z * cos_theta_i * sinf(phi_i);
}
else {
const float3 local_I = make_float3(dot(*wo, X), dot(*wo, Y), dot(*wo, Z));
sin_theta_i = local_I.x;
cos_theta_i = cos_from_sin(sin_theta_i);
const float phi_i = atan2f(local_I.z, local_I.y);
phi = phi_i - phi_o;
}
/* Evaluate throughput. */
float angles[8];
hair_alpha_angles(sin_theta_i, cos_theta_i, bsdf->alpha, angles);
*F = zero_spectrum();
*pdf = 0.0f;
for (int p = 0; p < 4; p++) {
const float Mp = longitudinal_scattering(
angles[2 * p], angles[2 * p + 1], sin_theta_o, cos_theta_o, hair_get_lobe_v(bsdf, p));
const float Np = azimuthal_scattering(phi, p, bsdf->s, gamma_o, gamma_t);
*F += Ap[p] * Mp * Np;
*pdf += lobe_pdf[p] * Mp * Np;
kernel_assert(isfinite_safe(*F) && isfinite_safe(*pdf));
}
return sampled_p;
} }
/* Evaluation function for our shader. */
ccl_device Spectrum bsdf_principled_hair_eval(KernelGlobals kg, ccl_device Spectrum bsdf_principled_hair_eval(KernelGlobals kg,
ccl_private ShaderData *sd, ccl_private const ShaderData *sd,
ccl_private const ShaderClosure *sc, ccl_private const ShaderClosure *sc,
float3 wo, const float3 wo,
ccl_private float *pdf) ccl_private float *pdf)
{ {
kernel_assert(isfinite_safe(sd->P) && isfinite_safe(sd->ray_length)); kernel_assert(isfinite_safe(sd->P) && isfinite_safe(sd->ray_length));
ccl_private const PrincipledHairBSDF *bsdf = (ccl_private const PrincipledHairBSDF *)sc; ccl_private const PrincipledHairBSDF *bsdf = (ccl_private const PrincipledHairBSDF *)sc;
const float3 Y = float4_to_float3(bsdf->extra->geom);
Spectrum eval; const float3 X = safe_normalize(sd->dPdu);
bsdf_principled_hair_impl<false>(kg, bsdf, sd, &wo, &eval, pdf, 0.0f, 0.0f); kernel_assert(fabsf(dot(X, Y)) < 1e-3f);
return eval; const float3 Z = safe_normalize(cross(X, Y));
/* local_I is the illumination direction. */
const float3 local_O = make_float3(dot(sd->wi, X), dot(sd->wi, Y), dot(sd->wi, Z));
const float3 local_I = make_float3(dot(wo, X), dot(wo, Y), dot(wo, Z));
const float sin_theta_o = local_O.x;
const float cos_theta_o = cos_from_sin(sin_theta_o);
const float phi_o = atan2f(local_O.z, local_O.y);
const float sin_theta_t = sin_theta_o / bsdf->eta;
const float cos_theta_t = cos_from_sin(sin_theta_t);
const float sin_gamma_o = bsdf->extra->geom.w;
const float cos_gamma_o = cos_from_sin(sin_gamma_o);
const float gamma_o = safe_asinf(sin_gamma_o);
const float sin_gamma_t = sin_gamma_o * cos_theta_o / sqrtf(sqr(bsdf->eta) - sqr(sin_theta_o));
const float cos_gamma_t = cos_from_sin(sin_gamma_t);
const float gamma_t = safe_asinf(sin_gamma_t);
const Spectrum T = exp(-bsdf->sigma * (2.0f * cos_gamma_t / cos_theta_t));
Spectrum Ap[4];
float Ap_energy[4];
hair_attenuation(
kg, fresnel_dielectric_cos(cos_theta_o * cos_gamma_o, bsdf->eta), T, Ap, Ap_energy);
const float sin_theta_i = local_I.x;
const float cos_theta_i = cos_from_sin(sin_theta_i);
const float phi_i = atan2f(local_I.z, local_I.y);
const float phi = phi_i - phi_o;
float angles[6];
hair_alpha_angles(sin_theta_i, cos_theta_i, bsdf->alpha, angles);
Spectrum F = zero_spectrum();
float F_energy = 0.0f;
/* Primary specular (R), Transmission (TT) and Secondary Specular (TRT). */
for (int i = 0; i < 3; i++) {
const float Mp = longitudinal_scattering(angles[2 * i],
angles[2 * i + 1],
sin_theta_o,
cos_theta_o,
(i == 0) ? bsdf->m0_roughness :
(i == 1) ? 0.25f * bsdf->v :
4.0f * bsdf->v);
const float Np = azimuthal_scattering(phi, i, bsdf->s, gamma_o, gamma_t);
F += Ap[i] * Mp * Np;
F_energy += Ap_energy[i] * Mp * Np;
kernel_assert(isfinite_safe(F) && isfinite_safe(F_energy));
}
/* Residual component (TRRT+). */
{
const float Mp = longitudinal_scattering(
sin_theta_i, cos_theta_i, sin_theta_o, cos_theta_o, 4.0f * bsdf->v);
const float Np = M_1_2PI_F;
F += Ap[3] * Mp * Np;
F_energy += Ap_energy[3] * Mp * Np;
kernel_assert(isfinite_safe(F) && isfinite_safe(F_energy));
}
*pdf = F_energy;
return F;
} }
/* Sampling function for the hair shader. */
ccl_device int bsdf_principled_hair_sample(KernelGlobals kg, ccl_device int bsdf_principled_hair_sample(KernelGlobals kg,
ccl_private const ShaderClosure *sc, ccl_private const ShaderClosure *sc,
ccl_private ShaderData *sd, ccl_private ShaderData *sd,
@ -413,13 +344,118 @@ ccl_device int bsdf_principled_hair_sample(KernelGlobals kg,
ccl_private float2 *sampled_roughness, ccl_private float2 *sampled_roughness,
ccl_private float *eta) ccl_private float *eta)
{ {
ccl_private const PrincipledHairBSDF *bsdf = (ccl_private const PrincipledHairBSDF *)sc; ccl_private PrincipledHairBSDF *bsdf = (ccl_private PrincipledHairBSDF *)sc;
int p = bsdf_principled_hair_impl<true>(kg, bsdf, sd, wo, eval, pdf, randu, randv); *sampled_roughness = make_float2(bsdf->m0_roughness, bsdf->m0_roughness);
*sampled_roughness = make_float2(bsdf->v_R, bsdf->v_R);
*eta = bsdf->eta; *eta = bsdf->eta;
const float3 Y = float4_to_float3(bsdf->extra->geom);
const float3 X = safe_normalize(sd->dPdu);
kernel_assert(fabsf(dot(X, Y)) < 1e-3f);
const float3 Z = safe_normalize(cross(X, Y));
const float3 local_O = make_float3(dot(sd->wi, X), dot(sd->wi, Y), dot(sd->wi, Z));
float2 u[2];
u[0] = make_float2(randu, randv);
u[1].x = lcg_step_float(&sd->lcg_state);
u[1].y = lcg_step_float(&sd->lcg_state);
const float sin_theta_o = local_O.x;
const float cos_theta_o = cos_from_sin(sin_theta_o);
const float phi_o = atan2f(local_O.z, local_O.y);
const float sin_theta_t = sin_theta_o / bsdf->eta;
const float cos_theta_t = cos_from_sin(sin_theta_t);
const float sin_gamma_o = bsdf->extra->geom.w;
const float cos_gamma_o = cos_from_sin(sin_gamma_o);
const float gamma_o = safe_asinf(sin_gamma_o);
const float sin_gamma_t = sin_gamma_o * cos_theta_o / sqrtf(sqr(bsdf->eta) - sqr(sin_theta_o));
const float cos_gamma_t = cos_from_sin(sin_gamma_t);
const float gamma_t = safe_asinf(sin_gamma_t);
const Spectrum T = exp(-bsdf->sigma * (2.0f * cos_gamma_t / cos_theta_t));
Spectrum Ap[4];
float Ap_energy[4];
hair_attenuation(
kg, fresnel_dielectric_cos(cos_theta_o * cos_gamma_o, bsdf->eta), T, Ap, Ap_energy);
int p = 0;
for (; p < 3; p++) {
if (u[0].x < Ap_energy[p]) {
break;
}
u[0].x -= Ap_energy[p];
}
float v = bsdf->v;
if (p == 1) {
v *= 0.25f;
}
if (p >= 2) {
v *= 4.0f;
}
u[1].x = max(u[1].x, 1e-5f);
const float fac = 1.0f + v * logf(u[1].x + (1.0f - u[1].x) * expf(-2.0f / v));
float sin_theta_i = -fac * sin_theta_o +
cos_from_sin(fac) * cosf(M_2PI_F * u[1].y) * cos_theta_o;
float cos_theta_i = cos_from_sin(sin_theta_i);
float angles[6];
if (p < 3) {
hair_alpha_angles(sin_theta_i, cos_theta_i, -bsdf->alpha, angles);
sin_theta_i = angles[2 * p];
cos_theta_i = angles[2 * p + 1];
}
float phi;
if (p < 3) {
phi = delta_phi(p, gamma_o, gamma_t) + sample_trimmed_logistic(u[0].y, bsdf->s);
}
else {
phi = M_2PI_F * u[0].y;
}
const float phi_i = phi_o + phi;
hair_alpha_angles(sin_theta_i, cos_theta_i, bsdf->alpha, angles);
Spectrum F = zero_spectrum();
float F_energy = 0.0f;
/* Primary specular (R), Transmission (TT) and Secondary Specular (TRT). */
for (int i = 0; i < 3; i++) {
const float Mp = longitudinal_scattering(angles[2 * i],
angles[2 * i + 1],
sin_theta_o,
cos_theta_o,
(i == 0) ? bsdf->m0_roughness :
(i == 1) ? 0.25f * bsdf->v :
4.0f * bsdf->v);
const float Np = azimuthal_scattering(phi, i, bsdf->s, gamma_o, gamma_t);
F += Ap[i] * Mp * Np;
F_energy += Ap_energy[i] * Mp * Np;
kernel_assert(isfinite_safe(F) && isfinite_safe(F_energy));
}
/* Residual component (TRRT+). */
{
const float Mp = longitudinal_scattering(
sin_theta_i, cos_theta_i, sin_theta_o, cos_theta_o, 4.0f * bsdf->v);
const float Np = M_1_2PI_F;
F += Ap[3] * Mp * Np;
F_energy += Ap_energy[3] * Mp * Np;
kernel_assert(isfinite_safe(F) && isfinite_safe(F_energy));
}
*eval = F;
*pdf = F_energy;
*wo = X * sin_theta_i + Y * cos_theta_i * cosf(phi_i) + Z * cos_theta_i * sinf(phi_i);
return LABEL_GLOSSY | ((p == 0) ? LABEL_REFLECT : LABEL_TRANSMIT); return LABEL_GLOSSY | ((p == 0) ? LABEL_REFLECT : LABEL_TRANSMIT);
} }
@ -430,30 +466,29 @@ ccl_device void bsdf_principled_hair_blur(ccl_private ShaderClosure *sc, float r
bsdf->v = fmaxf(roughness, bsdf->v); bsdf->v = fmaxf(roughness, bsdf->v);
bsdf->s = fmaxf(roughness, bsdf->s); bsdf->s = fmaxf(roughness, bsdf->s);
bsdf->v_R = fmaxf(roughness, bsdf->v_R); bsdf->m0_roughness = fmaxf(roughness, bsdf->m0_roughness);
} }
/* Hair Albedo */ /* Hair Albedo */
ccl_device_inline float bsdf_principled_hair_albedo_roughness_scale(const float u_rough) ccl_device_inline float bsdf_principled_hair_albedo_roughness_scale(
const float azimuthal_roughness)
{ {
const float x = u_rough; const float x = azimuthal_roughness;
return (((((0.245f * x) + 5.574f) * x - 10.73f) * x + 2.532f) * x - 0.215f) * x + 5.969f; return (((((0.245f * x) + 5.574f) * x - 10.73f) * x + 2.532f) * x - 0.215f) * x + 5.969f;
} }
ccl_device Spectrum bsdf_principled_hair_albedo(ccl_private const ShaderClosure *sc) ccl_device Spectrum bsdf_principled_hair_albedo(ccl_private const ShaderClosure *sc)
{ {
ccl_private PrincipledHairBSDF *bsdf = (ccl_private PrincipledHairBSDF *)sc; ccl_private PrincipledHairBSDF *bsdf = (ccl_private PrincipledHairBSDF *)sc;
/* This is simply the sum of the four Ap terms in hair_attenuation. */ return exp(-sqrt(bsdf->sigma) * bsdf_principled_hair_albedo_roughness_scale(bsdf->v));
const float3 T = bsdf->extra->T;
const float f = bsdf->extra->f;
return safe_divide(T * (1.0f - 2.0f * f) + make_spectrum(f), one_spectrum() - f * T);
} }
ccl_device_inline Spectrum bsdf_principled_hair_sigma_from_reflectance(const Spectrum color, ccl_device_inline Spectrum
const float u_rough) bsdf_principled_hair_sigma_from_reflectance(const Spectrum color, const float azimuthal_roughness)
{ {
const Spectrum sigma = log(color) / bsdf_principled_hair_albedo_roughness_scale(u_rough); const Spectrum sigma = log(color) /
bsdf_principled_hair_albedo_roughness_scale(azimuthal_roughness);
return sigma * sigma; return sigma * sigma;
} }

6
intern/cycles/kernel/osl/closures_setup.h
View File

@ -1078,13 +1078,15 @@ ccl_device void osl_closure_principled_hair_setup(KernelGlobals kg,
bsdf->N = ensure_valid_reflection(sd->Ng, sd->wi, closure->N); bsdf->N = ensure_valid_reflection(sd->Ng, sd->wi, closure->N);
bsdf->sigma = closure->sigma; bsdf->sigma = closure->sigma;
bsdf->v = closure->v;
bsdf->s = closure->s;
bsdf->alpha = closure->alpha; bsdf->alpha = closure->alpha;
bsdf->eta = closure->eta; bsdf->eta = closure->eta;
bsdf->m0_roughness = closure->m0_roughness;
bsdf->extra = extra; bsdf->extra = extra;
sd->flag |= bsdf_principled_hair_setup( sd->flag |= bsdf_principled_hair_setup(sd, bsdf);
sd, bsdf, closure->u_roughness, closure->coat_roughness, closure->v_roughness);
#endif #endif
} }

6
intern/cycles/kernel/osl/closures_template.h
View File

@ -238,9 +238,9 @@ OSL_CLOSURE_STRUCT_END(HairTransmission, hair_transmission)
OSL_CLOSURE_STRUCT_BEGIN(PrincipledHair, principled_hair) OSL_CLOSURE_STRUCT_BEGIN(PrincipledHair, principled_hair)
OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, VECTOR, packed_float3, N, NULL) OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, VECTOR, packed_float3, N, NULL)
OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, VECTOR, packed_float3, sigma, NULL) OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, VECTOR, packed_float3, sigma, NULL)
OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, u_roughness, NULL) OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, v, NULL)
OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, v_roughness, NULL) OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, s, NULL)
OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, coat_roughness, NULL) OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, m0_roughness, NULL)
OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, alpha, NULL) OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, alpha, NULL)
OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, eta, NULL) OSL_CLOSURE_STRUCT_MEMBER(PrincipledHair, FLOAT, float, eta, NULL)
OSL_CLOSURE_STRUCT_END(PrincipledHair, principled_hair) OSL_CLOSURE_STRUCT_END(PrincipledHair, principled_hair)

4
intern/cycles/kernel/osl/shaders/node_principled_hair_bsdf.osl
View File

@ -53,7 +53,7 @@ shader node_principled_hair_bsdf(color Color = color(0.017513, 0.005763, 0.00205
/* Compute roughness. */ /* Compute roughness. */
float factor_random_roughness = 1.0 + 2.0 * (random_value - 0.5) * RandomRoughness; float factor_random_roughness = 1.0 + 2.0 * (random_value - 0.5) * RandomRoughness;
float coat_roughness = 1.0 - clamp(Coat, 0.0, 1.0); float m0_roughness = 1.0 - clamp(Coat, 0.0, 1.0);
float roughness = Roughness * factor_random_roughness; float roughness = Roughness * factor_random_roughness;
float radial_roughness = RadialRoughness * factor_random_roughness; float radial_roughness = RadialRoughness * factor_random_roughness;
@ -88,5 +88,5 @@ shader node_principled_hair_bsdf(color Color = color(0.017513, 0.005763, 0.00205
sigma = sigma_from_concentration(0.0, 0.8054375); sigma = sigma_from_concentration(0.0, 0.8054375);
} }
BSDF = principled_hair(Normal, sigma, roughness, radial_roughness, coat_roughness, Offset, IOR); BSDF = principled_hair(Normal, sigma, roughness, radial_roughness, m0_roughness, Offset, IOR);
} }

8
intern/cycles/kernel/svm/closure.h
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@ -802,9 +802,12 @@ ccl_device_noinline int svm_node_closure_bsdf(KernelGlobals kg,
/* Remap Coat value to [0, 100]% of Roughness. */ /* Remap Coat value to [0, 100]% of Roughness. */
float coat = stack_load_float_default(stack, coat_ofs, data_node2.y); float coat = stack_load_float_default(stack, coat_ofs, data_node2.y);
float coat_roughness = 1.0f - clamp(coat, 0.0f, 1.0f); float m0_roughness = 1.0f - clamp(coat, 0.0f, 1.0f);
bsdf->N = N; bsdf->N = N;
bsdf->v = roughness;
bsdf->s = radial_roughness;
bsdf->m0_roughness = m0_roughness;
bsdf->alpha = alpha; bsdf->alpha = alpha;
bsdf->eta = ior; bsdf->eta = ior;
bsdf->extra = extra; bsdf->extra = extra;
@ -857,8 +860,7 @@ ccl_device_noinline int svm_node_closure_bsdf(KernelGlobals kg,
} }
} }
sd->flag |= bsdf_principled_hair_setup( sd->flag |= bsdf_principled_hair_setup(sd, bsdf);
sd, bsdf, roughness, coat_roughness, radial_roughness);
} }
break; break;
} }