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Diffstat (limited to 'intern/cycles/kernel/svm/emissive.h')
| -rw-r--r-- | intern/cycles/kernel/svm/emissive.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/intern/cycles/kernel/svm/emissive.h b/intern/cycles/kernel/svm/emissive.h new file mode 100644 index 00000000000..ed2b2e4aee8 --- /dev/null +++ b/intern/cycles/kernel/svm/emissive.h @@ -0,0 +1,83 @@ +/* + * Adapted from Open Shading Language with this license: + * + * Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al. + * All Rights Reserved. + * + * Modifications Copyright 2011, Blender Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Sony Pictures Imageworks nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + +CCL_NAMESPACE_BEGIN + +/* EMISSION CLOSURE */ + +__device float3 emissive_eval(const float3 Ng, const float3 I) +{ + float cosNO = fabsf(dot(Ng, I)); + float res = (cosNO > 0.0f)? M_1_PI_F: 0.0f; + + return make_float3(res, res, res); +} + +__device void emissive_sample(const float3 Ng, float randu, float randv, float3 *I, float *pdf) +{ + // We don't do anything sophisticated here for the step + // We just sample the whole cone uniformly to the cosine + float3 T, B; + make_orthonormals(Ng, &T, &B); + float phi = 2 * M_PI_F * randu; + + float cosTheta = sqrtf(1.0f - 1.0f * randv); + float sinTheta = sqrtf(1.0f - cosTheta * cosTheta); + *I = (cosf(phi) * sinTheta) * T + + (sinf(phi) * sinTheta) * B + + cosTheta * Ng; + + *pdf = M_1_PI_F; +} + +/// Return the probability distribution function in the direction I, +/// given the parameters and the light's surface normal. This MUST match +/// the PDF computed by sample(). +__device float emissive_pdf(const float3 Ng, const float3 I) +{ + float cosNO = fabsf(dot(Ng, I)); + return (cosNO > 0.0f)? M_1_PI_F: 0.0f; +} + +__device float3 svm_emissive_eval(ShaderData *sd) +{ + return sd->svm_closure_weight*emissive_eval(sd->Ng, sd->I); +} + +__device void svm_emissive_sample(ShaderData *sd, float randu, float randv, float3 *eval, float3 *I, float *pdf) +{ + *eval = sd->svm_closure_weight; + emissive_sample(sd->Ng, randu, randv, I, pdf); +} + +CCL_NAMESPACE_END + |