Add dynamic 'emitMtlx' Sdf file format argument

pablode · Apr 18, 2024 · 64d7592 · 64d7592
1 parent 49c3976
commit 64d7592
Show file tree

Hide file tree

Showing 3 changed files with 61 additions and 6 deletions.
diff --git a/src/libguc/plugInfo.json.in b/src/libguc/plugInfo.json.in
@@ -16,6 +16,15 @@
                         "primary": true,
                         "target": "usd"
                     }
+                },
+                "SdfMetadata": {
+                    "emitMtlx": {
+                        "type": "bool",
+                        "default": "false",
+                        "displayGroup": "Core",
+                        "appliesTo": [ "layers" ],
+                        "documentation:": "Emit MaterialX materials in addition to UsdPreviewSurfaces."
+                    }
                 }
             },
             "LibraryPath": "@PLUG_INFO_LIBRARY_PATH@",

diff --git a/src/libguc/src/fileFormat.cpp b/src/libguc/src/fileFormat.cpp
@@ -20,6 +20,7 @@
 #include <pxr/base/tf/registryManager.h>
 #include <pxr/base/tf/envSetting.h>
 #include <pxr/usd/usd/usdcFileFormat.h>
+#include <pxr/usd/pcp/dynamicFileFormatContext.h>
 
 #include <filesystem>
 
@@ -41,16 +42,14 @@ TF_DEFINE_PRIVATE_TOKENS(
   _tokens,
   (gltf)
   (glb)
+  (emitMtlx)
 );
 
 TF_REGISTRY_FUNCTION(TfType)
 {
   SDF_DEFINE_FILE_FORMAT(UsdGlTFFileFormat, SdfFileFormat);
 }
 
-TF_DEFINE_ENV_SETTING(USDGLTF_ENABLE_MTLX, false,
-                      "Whether the UsdGlTF Sdf plugin emits MaterialX materials or not.")
-
 // glTF files can contain embedded images. In order to support them in our Sdf file
 // format plugin, we create a temporary directory for each glTF file, write the images
 // to it, and reference them. Afterwards, this directory gets deleted, however I was
@@ -94,6 +93,19 @@ UsdGlTFFileFormat::~UsdGlTFFileFormat()
 {
 }
 
+SdfAbstractDataRefPtr UsdGlTFFileFormat::InitData(const FileFormatArguments& args) const
+{
+  UsdGlTFDataRefPtr data(new UsdGlTFData());
+
+  auto emitMtlxIt = args.find(_tokens->emitMtlx.GetText());
+  if (emitMtlxIt != args.end())
+  {
+    data->emitMtlx = (emitMtlxIt->second == "true");
+  }
+
+  return data;
+}
+
 bool UsdGlTFFileFormat::CanRead(const std::string& filePath) const
 {
   // FIXME: implement? In my tests, this is not even called.
@@ -111,13 +123,16 @@ bool UsdGlTFFileFormat::Read(SdfLayer* layer,
     return false;
   }
 
+  SdfAbstractDataRefPtr layerData = InitData(layer->GetFileFormatArguments());
+  UsdGlTFDataConstPtr data = TfDynamic_cast<const UsdGlTFDataConstPtr>(layerData);
+
   Converter::Params params = {};
   params.srcDir = fs::path(resolvedPath).parent_path();
   params.dstDir = s_tmpDirHolder.makeDir();
   params.mtlxFileName = ""; // Not needed because of Mtlx-as-UsdShade option
   params.copyExistingFiles = false;
   params.genRelativePaths = false;
-  params.emitMtlx = TfGetEnvSetting(USDGLTF_ENABLE_MTLX);
+  params.emitMtlx = data->emitMtlx;
   params.mtlxAsUsdShade = true;
   params.explicitColorspaceTransforms = false;
   params.gltfPbrImpl = Converter::GltfPbrImpl::Runtime;
@@ -144,6 +159,7 @@ bool UsdGlTFFileFormat::ReadFromString(SdfLayer* layer,
 {
   // glTF files often reference other files (e.g. a .bin payload or images).
   // Hence, without a file location, most glTF files can not be loaded correctly.
+  // TODO: but we could still try and return false on failure
   return false;
 }
 
@@ -165,4 +181,16 @@ bool UsdGlTFFileFormat::WriteToStream(const SdfSpecHandle &spec,
   return usdcFormat->WriteToStream(spec, out, indent);
 }
 
+void UsdGlTFFileFormat::ComposeFieldsForFileFormatArguments(const std::string& assetPath,
+                                                            const PcpDynamicFileFormatContext& context,
+                                                            FileFormatArguments* args,
+                                                            VtValue *dependencyContextData) const
+{
+  VtValue emitMtlxValue;
+  if (context.ComposeValue(_tokens->emitMtlx, &emitMtlxValue))
+  {
+    (*args)[_tokens->emitMtlx] = TfStringify(emitMtlxValue);
+  }
+}
+
 PXR_NAMESPACE_CLOSE_SCOPE
diff --git a/src/libguc/src/fileFormat.h b/src/libguc/src/fileFormat.h
@@ -17,8 +17,10 @@
 #pragma once
 
 #include <pxr/pxr.h>
+#include <pxr/usd/sdf/data.h>
 #include <pxr/usd/sdf/fileFormat.h>
 #include <pxr/base/tf/staticTokens.h>
+#include <pxr/usd/pcp/dynamicFileFormatInterface.h>
 #include <iosfwd>
 #include <string>
 
@@ -32,16 +34,20 @@ PXR_NAMESPACE_OPEN_SCOPE
 TF_DECLARE_PUBLIC_TOKENS(UsdGlTFFileFormatTokens, USDGLTF_FILE_FORMAT_TOKENS);
 
 TF_DECLARE_WEAK_AND_REF_PTRS(UsdGlTFFileFormat);
+TF_DECLARE_WEAK_AND_REF_PTRS(UsdGlTFData);
 
-class UsdGlTFFileFormat : public SdfFileFormat {
-public:
+class UsdGlTFFileFormat : public SdfFileFormat, public PcpDynamicFileFormatInterface
+{
+protected:
   SDF_FILE_FORMAT_FACTORY_ACCESS;
 
   UsdGlTFFileFormat();
 
   virtual ~UsdGlTFFileFormat();
 
 public:
+  SdfAbstractDataRefPtr InitData(const FileFormatArguments& args) const override;
+
   bool CanRead(const std::string &file) const override;
 
   bool Read(SdfLayer* layer,
@@ -59,6 +65,18 @@ class UsdGlTFFileFormat : public SdfFileFormat {
   bool WriteToStream(const SdfSpecHandle &spec,
                      std::ostream& out,
                      size_t indent) const override;
+
+public:
+  void ComposeFieldsForFileFormatArguments(const std::string& assetPath,
+                                           const PcpDynamicFileFormatContext& context,
+                                           FileFormatArguments* args,
+                                           VtValue *dependencyContextData) const override;
+};
+
+class UsdGlTFData : public SdfData
+{
+public:
+  bool emitMtlx = false;
 };
 
 PXR_NAMESPACE_CLOSE_SCOPE