diff options
Diffstat (limited to 'intern/cycles/kernel/closure/bssrdf.h')
| -rw-r--r-- | intern/cycles/kernel/closure/bssrdf.h | 119 |
1 files changed, 57 insertions, 62 deletions
diff --git a/intern/cycles/kernel/closure/bssrdf.h b/intern/cycles/kernel/closure/bssrdf.h index b87790f5f8a..47df0c5533a 100644 --- a/intern/cycles/kernel/closure/bssrdf.h +++ b/intern/cycles/kernel/closure/bssrdf.h @@ -8,8 +8,8 @@ CCL_NAMESPACE_BEGIN typedef struct Bssrdf { SHADER_CLOSURE_BASE; - float3 radius; - float3 albedo; + Spectrum radius; + Spectrum albedo; float roughness; float anisotropy; } Bssrdf; @@ -69,12 +69,13 @@ ccl_device void bssrdf_setup_radius(ccl_private Bssrdf *bssrdf, const float fourthirdA = (4.0f / 3.0f) * (1.0f + F_dr) / (1.0f - F_dr); /* From Jensen's `Fdr` ratio formula. */ - const float3 alpha_prime = make_float3( - bssrdf_dipole_compute_alpha_prime(bssrdf->albedo.x, fourthirdA), - bssrdf_dipole_compute_alpha_prime(bssrdf->albedo.y, fourthirdA), - bssrdf_dipole_compute_alpha_prime(bssrdf->albedo.z, fourthirdA)); + Spectrum alpha_prime; + FOREACH_SPECTRUM_CHANNEL (i) { + GET_SPECTRUM_CHANNEL(alpha_prime, i) = bssrdf_dipole_compute_alpha_prime( + GET_SPECTRUM_CHANNEL(bssrdf->albedo, i), fourthirdA); + } - bssrdf->radius *= sqrt(3.0f * (one_float3() - alpha_prime)); + bssrdf->radius *= sqrt(3.0f * (one_spectrum() - alpha_prime)); } } @@ -98,7 +99,7 @@ ccl_device_inline float bssrdf_burley_fitting(float A) /* Scale mean free path length so it gives similar looking result * to Cubic and Gaussian models. */ -ccl_device_inline float3 bssrdf_burley_compatible_mfp(float3 r) +ccl_device_inline Spectrum bssrdf_burley_compatible_mfp(Spectrum r) { return 0.25f * M_1_PI_F * r; } @@ -106,11 +107,13 @@ ccl_device_inline float3 bssrdf_burley_compatible_mfp(float3 r) ccl_device void bssrdf_burley_setup(ccl_private Bssrdf *bssrdf) { /* Mean free path length. */ - const float3 l = bssrdf_burley_compatible_mfp(bssrdf->radius); + const Spectrum l = bssrdf_burley_compatible_mfp(bssrdf->radius); /* Surface albedo. */ - const float3 A = bssrdf->albedo; - const float3 s = make_float3( - bssrdf_burley_fitting(A.x), bssrdf_burley_fitting(A.y), bssrdf_burley_fitting(A.z)); + const Spectrum A = bssrdf->albedo; + Spectrum s; + FOREACH_SPECTRUM_CHANNEL (i) { + GET_SPECTRUM_CHANNEL(s, i) = bssrdf_burley_fitting(GET_SPECTRUM_CHANNEL(A, i)); + } bssrdf->radius = l / s; } @@ -198,22 +201,18 @@ ccl_device void bssrdf_burley_sample(const float d, *h = safe_sqrtf(Rm * Rm - r_ * r_); } -ccl_device float bssrdf_num_channels(const float3 radius) +ccl_device float bssrdf_num_channels(const Spectrum radius) { float channels = 0; - if (radius.x > 0.0f) { - channels += 1.0f; - } - if (radius.y > 0.0f) { - channels += 1.0f; - } - if (radius.z > 0.0f) { - channels += 1.0f; + FOREACH_SPECTRUM_CHANNEL (i) { + if (GET_SPECTRUM_CHANNEL(radius, i) > 0.0f) { + channels += 1.0f; + } } return channels; } -ccl_device void bssrdf_sample(const float3 radius, +ccl_device void bssrdf_sample(const Spectrum radius, float xi, ccl_private float *r, ccl_private float *h) @@ -224,39 +223,45 @@ ccl_device void bssrdf_sample(const float3 radius, /* Sample color channel and reuse random number. Only a subset of channels * may be used if their radius was too small to handle as BSSRDF. */ xi *= num_channels; - - if (xi < 1.0f) { - sampled_radius = (radius.x > 0.0f) ? radius.x : (radius.y > 0.0f) ? radius.y : radius.z; - } - else if (xi < 2.0f) { - xi -= 1.0f; - sampled_radius = (radius.x > 0.0f && radius.y > 0.0f) ? radius.y : radius.z; - } - else { - xi -= 2.0f; - sampled_radius = radius.z; + sampled_radius = 0.0f; + + float sum = 0.0f; + FOREACH_SPECTRUM_CHANNEL (i) { + const float channel_radius = GET_SPECTRUM_CHANNEL(radius, i); + if (channel_radius > 0.0f) { + const float next_sum = sum + 1.0f; + if (xi < next_sum) { + xi -= sum; + sampled_radius = channel_radius; + break; + } + sum = next_sum; + } } /* Sample BSSRDF. */ bssrdf_burley_sample(sampled_radius, xi, r, h); } -ccl_device_forceinline float3 bssrdf_eval(const float3 radius, float r) +ccl_device_forceinline Spectrum bssrdf_eval(const Spectrum radius, float r) { - return make_float3(bssrdf_burley_pdf(radius.x, r), - bssrdf_burley_pdf(radius.y, r), - bssrdf_burley_pdf(radius.z, r)); + Spectrum result; + FOREACH_SPECTRUM_CHANNEL (i) { + GET_SPECTRUM_CHANNEL(result, i) = bssrdf_burley_pdf(GET_SPECTRUM_CHANNEL(radius, i), r); + } + return result; } -ccl_device_forceinline float bssrdf_pdf(const float3 radius, float r) +ccl_device_forceinline float bssrdf_pdf(const Spectrum radius, float r) { - float3 pdf = bssrdf_eval(radius, r); - return (pdf.x + pdf.y + pdf.z) / bssrdf_num_channels(radius); + Spectrum pdf = bssrdf_eval(radius, r); + return reduce_add(pdf) / bssrdf_num_channels(radius); } /* Setup */ -ccl_device_inline ccl_private Bssrdf *bssrdf_alloc(ccl_private ShaderData *sd, float3 weight) +ccl_device_inline ccl_private Bssrdf *bssrdf_alloc(ccl_private ShaderData *sd, + Spectrum weight) { ccl_private Bssrdf *bssrdf = (ccl_private Bssrdf *)closure_alloc( sd, sizeof(Bssrdf), CLOSURE_NONE_ID, weight); @@ -294,29 +299,19 @@ ccl_device int bssrdf_setup(ccl_private ShaderData *sd, } /* Verify if the radii are large enough to sample without precision issues. */ - int bssrdf_channels = 3; - float3 diffuse_weight = make_float3(0.0f, 0.0f, 0.0f); - - if (bssrdf->radius.x < BSSRDF_MIN_RADIUS) { - diffuse_weight.x = bssrdf->weight.x; - bssrdf->weight.x = 0.0f; - bssrdf->radius.x = 0.0f; - bssrdf_channels--; - } - if (bssrdf->radius.y < BSSRDF_MIN_RADIUS) { - diffuse_weight.y = bssrdf->weight.y; - bssrdf->weight.y = 0.0f; - bssrdf->radius.y = 0.0f; - bssrdf_channels--; - } - if (bssrdf->radius.z < BSSRDF_MIN_RADIUS) { - diffuse_weight.z = bssrdf->weight.z; - bssrdf->weight.z = 0.0f; - bssrdf->radius.z = 0.0f; - bssrdf_channels--; + int bssrdf_channels = SPECTRUM_CHANNELS; + Spectrum diffuse_weight = zero_spectrum(); + + FOREACH_SPECTRUM_CHANNEL (i) { + if (GET_SPECTRUM_CHANNEL(bssrdf->radius, i) < BSSRDF_MIN_RADIUS) { + GET_SPECTRUM_CHANNEL(diffuse_weight, i) = GET_SPECTRUM_CHANNEL(bssrdf->weight, i); + GET_SPECTRUM_CHANNEL(bssrdf->weight, i) = 0.0f; + GET_SPECTRUM_CHANNEL(bssrdf->radius, i) = 0.0f; + bssrdf_channels--; + } } - if (bssrdf_channels < 3) { + if (bssrdf_channels < SPECTRUM_CHANNELS) { /* Add diffuse BSDF if any radius too small. */ #ifdef __PRINCIPLED__ if (bssrdf->roughness != FLT_MAX) { |