Hydrogent: code cleanup + comments

Hydrogent/interface/HnRenderPass.hpp

@@ -49,7 +49,8 @@ struct HnMeshRenderParams
     float EmissionScale     = 1;
     float IBLScale          = 1;
 
-    float4 WireframeColor = float4(1, 1, 1, 1);
+    float4 WireframeColor = float4{1, 1, 1, 1};
+    float4 PointColor     = float4{1, 1, 1, 1};
 
     float4x4 Transform = float4x4::Identity();
 

Hydrogent/interface/Tasks/HnPostProcessTask.hpp

@@ -46,6 +46,7 @@ struct HnPostProcessTaskParams
 
     float4 SelectionColor = float4{0.75f, 0.75f, 0.25f, 0.5f};
 
+    /// Desaturation factor for non-selected objects
     float NonselectionDesaturationFactor = 0.0f;
 
     // Tone mappig attribs
@@ -75,7 +76,18 @@ struct HnPostProcessTaskParams
     }
 };
 
-/// Post processing task implementation in Hydrogent.
+/// Performs post processing:
+/// - Tone mapping
+/// - Selection outline
+/// - Converts output to sRGB, if needed
+///
+/// \remarks The task uses MeshId buffer to determine which pixels belong to selected objects.
+///          The index of the selected objects is negative.
+///
+///          The task gets offscreen color and mesh id Bprim buffer ids from the task context.
+///          It then retrieves the buffers from the render index.
+///          The final color buffer is also retrieved from the render index using the FinalColorTargetId
+///          extracted from the context.
 class HnPostProcessTask final : public HnTask
 {
 public:

Hydrogent/interface/Tasks/HnReadRprimIdTask.hpp

@@ -59,7 +59,7 @@ struct HnReadRprimIdTaskParams
     }
 };
 
-/// Render task implementation in Hydrogent.
+/// Reads RPrim index from the mesh id target.
 class HnReadRprimIdTask final : public HnTask
 {
 public:

Hydrogent/interface/Tasks/HnRenderEnvMapTask.hpp

@@ -50,7 +50,7 @@ struct HnRenderEnvMapTaskParams
     }
 };
 
-/// Post processing task implementation in Hydrogent.
+/// Renders the environment map.
 class HnRenderEnvMapTask final : public HnTask
 {
 public:

Hydrogent/interface/Tasks/HnRenderRprimsTask.hpp

@@ -49,9 +49,12 @@ struct HnRenderRprimsTaskParams
     float IBLScale          = 1;
 
     float4 WireframeColor = float4(1, 1, 1, 1);
+    float4 PointColor     = float4(1, 1, 1, 1);
 
     float4x4 Transform = float4x4::Identity();
 
+    /// Selected prim id.
+    /// Selected rprim is rendered with negative index.
     pxr::SdfPath SelectedPrimId;
 
     constexpr bool operator==(const HnRenderRprimsTaskParams& rhs) const
@@ -74,7 +77,9 @@ struct HnRenderRprimsTaskParams
     }
 };
 
-/// Render task implementation in Hydrogent.
+/// Renders the Rprims by executing the render pass.
+/// The task should be executed after the HnSetupRenderingTask that prepares
+/// render targets and sets the required task context parameters.
 class HnRenderRprimsTask final : public HnTask
 {
 public:

Hydrogent/interface/Tasks/HnSetupRenderingTask.hpp

@@ -51,15 +51,9 @@ struct HnSetupRenderingTaskParams
         return ColorFormat          == rhs.ColorFormat &&
                MeshIdFormat         == rhs.MeshIdFormat &&
                DepthFormat          == rhs.DepthFormat &&
-               RenderMode           == rhs.RenderMode &&
                FrontFaceCCW         == rhs.FrontFaceCCW &&
-               DebugView            == rhs.DebugView &&
-               OcclusionStrength    == rhs.OcclusionStrength &&
-               EmissionScale        == rhs.EmissionScale &&
-               IBLScale             == rhs.IBLScale &&
                ClearColor           == rhs.ClearColor &&
                ClearDepth           == rhs.ClearDepth &&
-               Transform            == rhs.Transform &&
                DepthBias            == rhs.DepthBias &&
                SlopeScaledDepthBias == rhs.SlopeScaledDepthBias &&
                DepthFunc            == rhs.DepthFunc &&
@@ -86,20 +80,11 @@ struct HnSetupRenderingTaskParams
     TEXTURE_FORMAT MeshIdFormat = TEX_FORMAT_UNKNOWN;
     TEXTURE_FORMAT DepthFormat  = TEX_FORMAT_UNKNOWN;
 
-    HN_RENDER_MODE RenderMode = HN_RENDER_MODE_SOLID;
-
     bool FrontFaceCCW = false;
 
-    int   DebugView         = 0;
-    float OcclusionStrength = 1;
-    float EmissionScale     = 1;
-    float IBLScale          = 1;
-
-    float4 ClearColor;
+    float4 ClearColor = {0, 0, 0, 0};
     float  ClearDepth = 1.f;
 
-    float4x4 Transform = float4x4::Identity();
-
     float                  DepthBias            = 0;
     float                  SlopeScaledDepthBias = 0;
     pxr::HdCompareFunction DepthFunc            = pxr::HdCmpFuncLess;
@@ -120,7 +105,15 @@ struct HnSetupRenderingTaskParams
     pxr::SdfPath FinalColorTargetId;
 };
 
-/// Post processing task implementation in Hydrogent.
+/// Sets up rendering state for subsequent tasks:
+/// - Prepares color and mesh id render targets and depth buffer
+///   - Retrieves final color Bprim from the render index using the FinalColorTargetId
+///   - (Re)creates the render targets if necessary
+///   - Inserts them into the render index as Bprims
+///   - Passes Bprim Id to subsequent tasks via the task context
+/// - Updates render pass state
+/// - Updates task context with the render pass state so that subsequent tasks can use it
+/// - Binds and clears render targets and depth buffer
 class HnSetupRenderingTask final : public HnTask
 {
 public:

Hydrogent/shaders/HnPostProcess.psh

@@ -23,6 +23,7 @@ void main(in PSInput PSIn,
     Color.rgb = ToneMap(Color.rgb, g_Attribs.ToneMapping, g_Attribs.AverageLogLum);
 #endif
 
+    // Selected rprim is rendered with negative index
     float IsSelected0 = g_MeshId.Load(int3(PSIn.Pos.xy + float2(-1.0, -1.0), 0)).r < 0.0 ? -1.0 : +1.0;
     float IsSelected1 = g_MeshId.Load(int3(PSIn.Pos.xy + float2( 0.0, -1.0), 0)).r < 0.0 ? -1.0 : +1.0;
     float IsSelected2 = g_MeshId.Load(int3(PSIn.Pos.xy + float2(+1.0, -1.0), 0)).r < 0.0 ? -1.0 : +1.0;

Hydrogent/shaders_inc/HnPostProcess.psh.h

@@ -23,6 +23,7 @@
 "    Color.rgb = ToneMap(Color.rgb, g_Attribs.ToneMapping, g_Attribs.AverageLogLum);\n"
 "#endif\n"
 "\n"
+"    // Selected rprim is rendered with negative index\n"
 "    float IsSelected0 = g_MeshId.Load(int3(PSIn.Pos.xy + float2(-1.0, -1.0), 0)).r < 0.0 ? -1.0 : +1.0;\n"
 "    float IsSelected1 = g_MeshId.Load(int3(PSIn.Pos.xy + float2( 0.0, -1.0), 0)).r < 0.0 ? -1.0 : +1.0;\n"
 "    float IsSelected2 = g_MeshId.Load(int3(PSIn.Pos.xy + float2(+1.0, -1.0), 0)).r < 0.0 ? -1.0 : +1.0;\n"

Hydrogent/src/HnRenderPass.cpp

@@ -320,7 +320,7 @@ void HnRenderPass::RenderMesh(RenderState&      State,
         RendererParams.IBLScale          = m_Params.IBLScale;
 
         RendererParams.PrefilteredCubeMipLevels = 5; //m_Settings.UseIBL ? static_cast<float>(m_pPrefilteredEnvMapSRV->GetTexture()->GetDesc().MipLevels) : 0.f;
-        RendererParams.WireframeColor           = m_Params.WireframeColor;
+        RendererParams.WireframeColor           = m_Params.RenderMode == HN_RENDER_MODE_POINTS ? m_Params.PointColor : m_Params.WireframeColor;
         RendererParams.HighlightColor           = float4{0, 0, 0, 0};
 
         // Tone mapping is performed in the post-processing pass

Hydrogent/src/HnRenderPassState.cpp

@@ -60,14 +60,11 @@ void HnRenderPassState::Begin(IDeviceContext* pContext)
     VERIFY(_stepSizeLighting == 0, "Step size lighting is not supported");
 
     //GfVec4f _overrideColor;
-    //GfVec4f _wireframeColor;
-    //GfVec4f _pointColor;
     //GfVec4f _maskColor;
     //GfVec4f _indicatorColor;
     //float   _pointSelectedSize;
     //GfVec2f _drawRange;
 
-    pContext->SetStencilRef(_stencilRef);
     pContext->SetBlendFactors(_blendConstantColor.data());
     Viewport VP{_viewport[0], _viewport[1], _viewport[2], _viewport[3]};
     pContext->SetViewports(1, &VP, 0, 0);

Hydrogent/src/Tasks/HnPostProcessTask.cpp

@@ -189,6 +189,7 @@ void HnPostProcessTask::Prepare(pxr::HdTaskContext* TaskCtx,
 {
     m_RenderIndex = RenderIndex;
 
+    // Final color Bprim is initialized by the HnSetupRenderingTask.
     ITextureView* pFinalColorRTV = GetRenderBufferTarget(*RenderIndex, TaskCtx, HnRenderResourceTokens->finalColorTarget);
     if (pFinalColorRTV == nullptr)
     {
@@ -213,6 +214,9 @@ void HnPostProcessTask::Execute(pxr::HdTaskContext* TaskCtx)
         UNEXPECTED("Render index is null. This likely indicates that Prepare() has not been called.");
         return;
     }
+
+    // Render target Bprims are initialized by the HnSetupRenderingTask.
+
     ITextureView* pFinalColorRTV = GetRenderBufferTarget(*m_RenderIndex, TaskCtx, HnRenderResourceTokens->finalColorTarget);
     if (pFinalColorRTV == nullptr)
     {

Hydrogent/src/Tasks/HnReadRprimIdTask.cpp

@@ -87,6 +87,9 @@ void HnReadRprimIdTask::Execute(pxr::HdTaskContext* TaskCtx)
         UNEXPECTED("Mesh ID readback queue is null.");
         return;
     }
+
+    // Render target Bprims are initialized by the HnSetupRenderingTask.
+
     ITextureView* pMeshIdRTV = GetRenderBufferTarget(*m_RenderIndex, TaskCtx, HnRenderResourceTokens->meshIdTarget);
     if (pMeshIdRTV == nullptr)
     {

Hydrogent/src/Tasks/HnRenderRprimsTask.cpp

@@ -61,6 +61,7 @@ void HnRenderRprimsTask::UpdateRenderPassParams(const HnRenderRprimsTaskParams&
     RenderPassParams.EmissionScale     = Params.EmissionScale;
     RenderPassParams.IBLScale          = Params.IBLScale;
     RenderPassParams.WireframeColor    = Params.WireframeColor;
+    RenderPassParams.PointColor        = Params.PointColor;
     RenderPassParams.Transform         = Params.Transform;
     RenderPassParams.SelectedPrimId    = Params.SelectedPrimId;
     static_cast<HnRenderPass*>(m_RenderPass.get())->SetMeshRenderParams(RenderPassParams);
@@ -74,9 +75,8 @@ void HnRenderRprimsTask::Sync(pxr::HdSceneDelegate* Delegate,
 
     if (*DirtyBits & pxr::HdChangeTracker::DirtyCollection)
     {
-        pxr::VtValue CollectionVal = Delegate->Get(GetId(), pxr::HdTokens->collection);
-
-        pxr::HdRprimCollection Collection = CollectionVal.Get<pxr::HdRprimCollection>();
+        pxr::VtValue           CollectionVal = Delegate->Get(GetId(), pxr::HdTokens->collection);
+        pxr::HdRprimCollection Collection    = CollectionVal.Get<pxr::HdRprimCollection>();
 
         if (Collection.GetName().IsEmpty())
         {
@@ -101,16 +101,11 @@ void HnRenderRprimsTask::Sync(pxr::HdSceneDelegate* Delegate,
 
     if (*DirtyBits & pxr::HdChangeTracker::DirtyParams)
     {
-        pxr::VtValue ParamsValue = Delegate->Get(GetId(), pxr::HdTokens->params);
-        if (ParamsValue.IsHolding<HnRenderRprimsTaskParams>())
+        HnRenderRprimsTaskParams Params;
+        if (GetTaskParams(Delegate, Params))
         {
-            HnRenderRprimsTaskParams Params = ParamsValue.UncheckedGet<HnRenderRprimsTaskParams>();
             UpdateRenderPassParams(Params);
         }
-        else
-        {
-            UNEXPECTED("Unknown task parameters type: ", ParamsValue.GetTypeName());
-        }
     }
 
     if (*DirtyBits & pxr::HdChangeTracker::DirtyRenderTags)

Hydrogent/src/Tasks/HnSetupRenderingTask.cpp

@@ -143,7 +143,7 @@ void HnSetupRenderingTask::PrepareRenderTargets(pxr::HdRenderIndex* RenderIndex,
         auto TargetDesc      = FinalTargetDesc;
         TargetDesc.Name      = Name;
         TargetDesc.Format    = Format;
-        TargetDesc.BindFlags = (IsDepth ? BIND_DEPTH_STENCIL : BIND_RENDER_TARGET) | BIND_SHADER_RESOURCE;
+        TargetDesc.BindFlags = IsDepth ? BIND_DEPTH_STENCIL : (BIND_RENDER_TARGET | BIND_SHADER_RESOURCE);
 
         RefCntAutoPtr<ITexture> pTarget;
         pDevice->CreateTexture(TargetDesc, nullptr, &pTarget);
@@ -203,6 +203,7 @@ void HnSetupRenderingTask::Execute(pxr::HdTaskContext* TaskCtx)
     constexpr float Zero[] = {0, 0, 0, 0};
     pCtx->ClearRenderTarget(pRTVs[1], Zero, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
     pCtx->ClearDepthStencil(m_pDepthDSV, CLEAR_DEPTH_FLAG, m_ClearDepth, 0, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
+    pCtx->SetStencilRef(m_RenderPassState->GetStencilRef());
 }
 
 } // namespace USD