Supporting transparent draws for HdSt.

Fix: #2
Autodesk · Aug 30, 2018 · d96f20e · d96f20e
1 parent 8086dc7
commit d96f20e
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Showing 2 changed files with 56 additions and 10 deletions.
diff --git a/src/hdmaya/adapters/imagePlaneMaterialAdapter.cpp b/src/hdmaya/adapters/imagePlaneMaterialAdapter.cpp
@@ -71,8 +71,8 @@ const char* _simpleTexturedSurfaceSource =
 
 vec4 surfaceShader(vec4 Peye, vec3 Neye, vec4 color, vec4 patchCoord)
 {
-#if defined(HD_HAS_emissiveColor)
-    return HdGet_emissiveColor();
+#if defined(HD_HAS_color)
+    return HdGet_color();
 #else
     return vec4(1.0, 0.0, 0.0, 1.0);
 #endif
@@ -86,7 +86,7 @@ static const std::pair<std::string, std::string> _textureShaderSource =
 }();
 
 const TfTokenVector _stSamplerCoords = {TfToken("st")};
-TF_DEFINE_PRIVATE_TOKENS(_tokens, (emissiveColor));
+TF_DEFINE_PRIVATE_TOKENS(_tokens, (color));
 const MString _imageName("imageName");
 
 } // namespace
@@ -144,13 +144,12 @@ class HdMayaImagePlaneMaterialAdapter : public HdMayaMaterialAdapter {
         MFnDependencyNode node(_node, &status);
         if (ARCH_UNLIKELY(!status)) { return {}; }
 
-        if (_RegisterTexture(node, _tokens->emissiveColor)) {
-            HdMaterialParam emission(
-                HdMaterialParam::ParamTypeTexture, _tokens->emissiveColor,
+        if (_RegisterTexture(node, _tokens->color)) {
+            HdMaterialParam color(
+                HdMaterialParam::ParamTypeTexture, _tokens->color,
                 VtValue(GfVec4f(0.0f, 0.0f, 0.0f, 1.0f)),
-                GetID().AppendProperty(_tokens->emissiveColor),
-                _stSamplerCoords);
-            return {emission};
+                GetID().AppendProperty(_tokens->color), _stSamplerCoords);
+            return {color};
         }
         TF_DEBUG(HDMAYA_ADAPTER_IMAGEPLANES)
             .Msg("Unexpected failure to register texture\n");

diff --git a/src/plugin/renderOverride.cpp b/src/plugin/renderOverride.cpp
@@ -149,6 +149,45 @@ class HdMayaRender : public MHWRender::MUserRenderOperation {
     HdMayaRenderOverride* _override;
 };
 
+class SetRenderGLState {
+public:
+    SetRenderGLState(HdGeomStyle geomStyle) :
+        _geomStyle(geomStyle) {
+        if (_geomStyle == HdGeomStylePolygons) {
+            glGetIntegerv(GL_BLEND_SRC_ALPHA, &_oldBlendFunc);
+            glGetBooleanv(GL_BLEND, &_oldBlend);
+
+            if (_oldBlendFunc != _blendFunc) {
+                glBlendFunc(GL_SRC_ALPHA, _blendFunc);
+            }
+
+            if (_oldBlend != _blend) {
+                glEnable(GL_BLEND);
+            }
+        }
+    }
+
+    ~SetRenderGLState() {
+        if (_geomStyle == HdGeomStylePolygons) {
+            if (_oldBlend != _blend) {
+                glDisable(GL_BLEND);
+            }
+
+            if (_oldBlendFunc != _blendFunc) {
+                glBlendFunc(GL_SRC_ALPHA, _oldBlendFunc);
+            }
+        }
+    }
+private:
+    // non-odr
+    constexpr static int _blendFunc = GL_ONE_MINUS_SRC_ALPHA;
+    constexpr static GLboolean _blend = GL_TRUE;
+
+    HdGeomStyle _geomStyle = HdGeomStylePolygons;
+    int _oldBlendFunc = _blendFunc;
+    GLboolean _oldBlend = _blend;
+};
+
 } // namespace
 
 HdMayaRenderOverride::HdMayaRenderOverride()
@@ -358,7 +397,15 @@ MStatus HdMayaRenderOverride::Render(
     _taskController->SetSelectionColor(_colorSelectionHighlightColor);
     _taskController->SetEnableSelection(_colorSelectionHighlight);
 
-    renderFrame();
+    // This is required for HdStream to display transparency.
+    // We should fix this upstream, so HdStream can setup
+    // all the required states.
+    if (_rendererName == _tokens->HdStreamRendererPlugin) {
+        SetRenderGLState state(params.geomStyle);
+        renderFrame();
+    } else {
+        renderFrame();
+    }
 
     // This causes issues with the embree delegate and potentially others.
     if (_wireframeSelectionHighlight &&