Cycles render engine, initial commit. This is the engine itself, blender modifications and build instructions will follow later.

Cycles uses code from some great open source projects, many thanks them:

* BVH building and traversal code from NVidia's "Understanding the Efficiency of Ray Traversal on GPUs":
http://code.google.com/p/understanding-the-efficiency-of-ray-traversal-on-gpus/
* Open Shading Language for a large part of the shading system:
http://code.google.com/p/openshadinglanguage/
* Blender for procedural textures and a few other nodes.
* Approximate Catmull Clark subdivision from NVidia Mesh tools:
http://code.google.com/p/nvidia-mesh-tools/
* Sobol direction vectors from:
http://web.maths.unsw.edu.au/~fkuo/sobol/
* Film response functions from:
http://www.cs.columbia.edu/CAVE/software/softlib/dorf.php

1 files changed, 83 insertions, 0 deletions

diff --git a/intern/cycles/kernel/svm/emissive.h b/intern/cycles/kernel/svm/emissive.h
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--- /dev/null
+++ b/intern/cycles/kernel/svm/emissive.h
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+/* 
+ * 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
+