1 files changed, 170 insertions, 0 deletions
diff --git a/intern/cycles/hydra/session.cpp b/intern/cycles/hydra/session.cpp
new file mode 100644
index 00000000000..f6865bdedd1
--- /dev/null
+++ b/intern/cycles/hydra/session.cpp
@@ -0,0 +1,170 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright 2022 NVIDIA Corporation
+ * Copyright 2022 Blender Foundation */
+
+#include "hydra/session.h"
+#include "scene/shader.h"
+// Have to include shader.h before background.h so that 'set_shader' uses the correct 'set'
+// overload taking a 'Node *', rather than the one taking a 'bool'
+#include "scene/background.h"
+#include "scene/light.h"
+#include "scene/shader_graph.h"
+#include "scene/shader_nodes.h"
+#include "session/session.h"
+
+HDCYCLES_NAMESPACE_OPEN_SCOPE
+
+namespace {
+
+const std::unordered_map<TfToken, PassType, TfToken::HashFunctor> kAovToPass = {
+    {HdAovTokens->color, PASS_COMBINED},
+    {HdAovTokens->depth, PASS_DEPTH},
+    {HdAovTokens->normal, PASS_NORMAL},
+    {HdAovTokens->primId, PASS_OBJECT_ID},
+    {HdAovTokens->instanceId, PASS_AOV_VALUE},
+};
+
+}  // namespace
+
+SceneLock::SceneLock(const HdRenderParam *renderParam)
+    : scene(static_cast<const HdCyclesSession *>(renderParam)->session->scene),
+      sceneLock(scene->mutex)
+{
+}
+
+SceneLock::~SceneLock()
+{
+}
+
+HdCyclesSession::HdCyclesSession(Session *session_) : session(session_), _ownCyclesSession(false)
+{
+}
+
+HdCyclesSession::HdCyclesSession(const SessionParams &params)
+    : session(new Session(params, SceneParams())), _ownCyclesSession(true)
+{
+  Scene *const scene = session->scene;
+
+  // Create background with ambient light
+  {
+    ShaderGraph *graph = new ShaderGraph();
+
+    BackgroundNode *bgNode = graph->create_node<BackgroundNode>();
+    bgNode->set_color(one_float3());
+    graph->add(bgNode);
+
+    graph->connect(bgNode->output("Background"), graph->output()->input("Surface"));
+
+    scene->default_background->set_graph(graph);
+    scene->default_background->tag_update(scene);
+  }
+
+  // Wire up object color in default surface material
+  {
+    ShaderGraph *graph = new ShaderGraph();
+
+    ObjectInfoNode *objectNode = graph->create_node<ObjectInfoNode>();
+    graph->add(objectNode);
+
+    DiffuseBsdfNode *diffuseNode = graph->create_node<DiffuseBsdfNode>();
+    graph->add(diffuseNode);
+
+    graph->connect(objectNode->output("Color"), diffuseNode->input("Color"));
+    graph->connect(diffuseNode->output("BSDF"), graph->output()->input("Surface"));
+
+#if 1
+    // Create the instanceId AOV output
+    const ustring instanceId(HdAovTokens->instanceId.GetString());
+
+    OutputAOVNode *aovNode = graph->create_node<OutputAOVNode>();
+    aovNode->set_name(instanceId);
+    graph->add(aovNode);
+
+    AttributeNode *instanceIdNode = graph->create_node<AttributeNode>();
+    instanceIdNode->set_attribute(instanceId);
+    graph->add(instanceIdNode);
+
+    graph->connect(instanceIdNode->output("Fac"), aovNode->input("Value"));
+#endif
+
+    scene->default_surface->set_graph(graph);
+    scene->default_surface->tag_update(scene);
+  }
+}
+
+HdCyclesSession::~HdCyclesSession()
+{
+  if (_ownCyclesSession) {
+    delete session;
+  }
+}
+
+void HdCyclesSession::UpdateScene()
+{
+  Scene *const scene = session->scene;
+
+  // Update background depending on presence of a background light
+  if (scene->light_manager->need_update()) {
+    Light *background_light = nullptr;
+    for (Light *light : scene->lights) {
+      if (light->get_light_type() == LIGHT_BACKGROUND) {
+        background_light = light;
+        break;
+      }
+    }
+
+    if (!background_light) {
+      scene->background->set_shader(scene->default_background);
+      scene->background->set_transparent(true);
+    }
+    else {
+      scene->background->set_shader(background_light->get_shader());
+      scene->background->set_transparent(false);
+    }
+
+    scene->background->tag_update(scene);
+  }
+}
+
+void HdCyclesSession::SyncAovBindings(const HdRenderPassAovBindingVector &aovBindings)
+{
+  Scene *const scene = session->scene;
+
+  // Delete all existing passes
+  scene->delete_nodes(set<Pass *>(scene->passes.begin(), scene->passes.end()));
+
+  // Update passes with requested AOV bindings
+  _aovBindings = aovBindings;
+  for (const HdRenderPassAovBinding &aovBinding : aovBindings) {
+    const auto cyclesAov = kAovToPass.find(aovBinding.aovName);
+    if (cyclesAov == kAovToPass.end()) {
+      // TODO: Use PASS_AOV_COLOR and PASS_AOV_VALUE for these?
+      TF_WARN("Unknown pass %s", aovBinding.aovName.GetText());
+      continue;
+    }
+
+    const PassType type = cyclesAov->second;
+    const PassMode mode = PassMode::DENOISED;
+
+    Pass *pass = scene->create_node<Pass>();
+    pass->set_type(type);
+    pass->set_mode(mode);
+    pass->set_name(ustring(aovBinding.aovName.GetString()));
+  }
+}
+
+void HdCyclesSession::RemoveAovBinding(HdRenderBuffer *renderBuffer)
+{
+  for (HdRenderPassAovBinding &aovBinding : _aovBindings) {
+    if (renderBuffer == aovBinding.renderBuffer) {
+      aovBinding.renderBuffer = nullptr;
+      break;
+    }
+  }
+
+  if (renderBuffer == _displayAovBinding.renderBuffer) {
+    _displayAovBinding.renderBuffer = nullptr;
+  }
+}
+
+HDCYCLES_NAMESPACE_CLOSE_SCOPE