1 files changed, 141 insertions, 0 deletions
diff --git a/intern/cycles/kernel/svm/ao.h b/intern/cycles/kernel/svm/ao.h
new file mode 100644
index 00000000000..678f49c8ccd
--- /dev/null
+++ b/intern/cycles/kernel/svm/ao.h
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2011-2018 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "kernel/bvh/bvh.h"
+
+CCL_NAMESPACE_BEGIN
+
+#ifdef __SHADER_RAYTRACE__
+
+#  ifdef __KERNEL_OPTIX__
+extern "C" __device__ float __direct_callable__svm_node_ao(
+#  else
+ccl_device float svm_ao(
+#  endif
+    KernelGlobals kg,
+    ConstIntegratorState state,
+    ccl_private ShaderData *sd,
+    float3 N,
+    float max_dist,
+    int num_samples,
+    int flags)
+{
+  if (flags & NODE_AO_GLOBAL_RADIUS) {
+    max_dist = kernel_data.integrator.ao_bounces_distance;
+  }
+
+  /* Early out if no sampling needed. */
+  if (max_dist <= 0.0f || num_samples < 1 || sd->object == OBJECT_NONE) {
+    return 1.0f;
+  }
+
+  /* Can't raytrace from shaders like displacement, before BVH exists. */
+  if (kernel_data.bvh.bvh_layout == BVH_LAYOUT_NONE) {
+    return 1.0f;
+  }
+
+  if (flags & NODE_AO_INSIDE) {
+    N = -N;
+  }
+
+  float3 T, B;
+  make_orthonormals(N, &T, &B);
+
+  /* TODO: support ray-tracing in shadow shader evaluation? */
+  RNGState rng_state;
+  path_state_rng_load(state, &rng_state);
+
+  int unoccluded = 0;
+  for (int sample = 0; sample < num_samples; sample++) {
+    float disk_u, disk_v;
+    path_branched_rng_2D(kg, &rng_state, sample, num_samples, PRNG_BEVEL_U, &disk_u, &disk_v);
+
+    float2 d = concentric_sample_disk(disk_u, disk_v);
+    float3 D = make_float3(d.x, d.y, safe_sqrtf(1.0f - dot(d, d)));
+
+    /* Create ray. */
+    Ray ray;
+    ray.P = ray_offset(sd->P, N);
+    ray.D = D.x * T + D.y * B + D.z * N;
+    ray.t = max_dist;
+    ray.time = sd->time;
+    ray.dP = differential_zero_compact();
+    ray.dD = differential_zero_compact();
+
+    if (flags & NODE_AO_ONLY_LOCAL) {
+      if (!scene_intersect_local(kg, &ray, NULL, sd->object, NULL, 0)) {
+        unoccluded++;
+      }
+    }
+    else {
+      Intersection isect;
+      if (!scene_intersect(kg, &ray, PATH_RAY_SHADOW_OPAQUE, &isect)) {
+        unoccluded++;
+      }
+    }
+  }
+
+  return ((float)unoccluded) / num_samples;
+}
+
+template<uint node_feature_mask, typename ConstIntegratorGenericState>
+#  if defined(__KERNEL_OPTIX__)
+ccl_device_inline
+#  else
+ccl_device_noinline
+#  endif
+    void
+    svm_node_ao(KernelGlobals kg,
+                ConstIntegratorGenericState state,
+                ccl_private ShaderData *sd,
+                ccl_private float *stack,
+                uint4 node)
+{
+  uint flags, dist_offset, normal_offset, out_ao_offset;
+  svm_unpack_node_uchar4(node.y, &flags, &dist_offset, &normal_offset, &out_ao_offset);
+
+  uint color_offset, out_color_offset, samples;
+  svm_unpack_node_uchar3(node.z, &color_offset, &out_color_offset, &samples);
+
+  float ao = 1.0f;
+
+  IF_KERNEL_NODES_FEATURE(RAYTRACE)
+  {
+    float dist = stack_load_float_default(stack, dist_offset, node.w);
+    float3 normal = stack_valid(normal_offset) ? stack_load_float3(stack, normal_offset) : sd->N;
+
+#  ifdef __KERNEL_OPTIX__
+    ao = optixDirectCall<float>(0, kg, state, sd, normal, dist, samples, flags);
+#  else
+    ao = svm_ao(kg, state, sd, normal, dist, samples, flags);
+#  endif
+  }
+
+  if (stack_valid(out_ao_offset)) {
+    stack_store_float(stack, out_ao_offset, ao);
+  }
+
+  if (stack_valid(out_color_offset)) {
+    float3 color = stack_load_float3(stack, color_offset);
+    stack_store_float3(stack, out_color_offset, ao * color);
+  }
+}
+
+#endif /* __SHADER_RAYTRACE__ */
+
+CCL_NAMESPACE_END