Improve parsing Prim metadataum and pprint.

2026-01-18 01:11:17 +01:00 · 2022-08-22 23:00:56 +09:00
parent 3402b2c739
commit a3eaae1c01
10 changed files with 246 additions and 46 deletions
--- a/src/ascii-parser.cc
+++ b/src/ascii-parser.cc
@@ -200,6 +200,7 @@ static void RegisterStageMetas(
  metas["subLayers"] = AsciiParser::VariableDef(value::kAssetPath, "subLayers");
 }

+#if 0
 // T = better-enums
 template<class T>
 class OneOf
@@ -218,12 +219,14 @@ class OneOf
    return nonstd::make_unexpected(err_msg);
  }
 };
+#endif

 static void RegisterPrimMetas(
    std::map<std::string, AsciiParser::VariableDef> &metas) {
  metas.clear();

-  metas["kind"] = AsciiParser::VariableDef(value::kString, "kind", OneOf<Kind>());
+  //metas["kind"] = AsciiParser::VariableDef(value::kString, "kind", OneOf<Kind>());
+  metas["kind"] = AsciiParser::VariableDef(value::kToken, "kind");

  // Composition arcs
  // Type can be array. i.e. path, path[]
@@ -2371,7 +2374,7 @@ bool AsciiParser::ParseDictElement(std::string *out_key,

  //
  // Supports limited types for customData/Dictionary.
-  // TODO: array_qual
+  // TODO: support more types?
  //
  MetaVariable var;
  if (type_name == value::kBool) {
@@ -2381,17 +2384,33 @@ bool AsciiParser::ParseDictElement(std::string *out_key,
    }
    var.value = val;
  } else if (type_name == "float") {
-    float val;
-    if (!ReadBasicType(&val)) {
-      PUSH_ERROR_AND_RETURN("Failed to parse `float`");
+    if (array_qual) {
+      std::vector<float> vss;
+      if (!ParseBasicTypeArray(&vss)) {
+        PUSH_ERROR_AND_RETURN("Failed to parse `float[]`");
+      }
+      var.value = vss;
+    } else {
+      float val;
+      if (!ReadBasicType(&val)) {
+        PUSH_ERROR_AND_RETURN("Failed to parse `float`");
+      }
+      var.value = val;
    }
-    var.value = val;
  } else if (type_name == "string") {
-    std::string str;
-    if (!ReadStringLiteral(&str)) {
-      PUSH_ERROR_AND_RETURN("Failed to parse `string`");
+    if (array_qual) {
+      std::vector<std::string> strs;
+      if (!ParseBasicTypeArray(&strs)) {
+        PUSH_ERROR_AND_RETURN("Failed to parse `string[]`");
+      }
+      var.value = strs;
+    } else {
+      std::string str;
+      if (!ReadStringLiteral(&str)) {
+        PUSH_ERROR_AND_RETURN("Failed to parse `string`");
+      }
+      var.value = str;
    }
-    var.value = str;
  } else if (type_name == "token") {
    if (array_qual) {
      std::vector<std::string> strs;
@@ -2414,13 +2433,24 @@ bool AsciiParser::ParseDictElement(std::string *out_key,
  } else if (type_name == "dictionary") {
    std::map<std::string, MetaVariable> dict;

+    DCOUT("Parse dictionary");
    if (!ParseDict(&dict)) {
      PUSH_ERROR_AND_RETURN("Failed to parse `dictionary`");
    }
+    var.obj_value = dict;
  } else {
    PUSH_ERROR_AND_RETURN("TODO: type = " + type_name);
  }

+  var.type = type_name;
+  if (array_qual) {
+    // TODO: 2D array
+    var.type += "[]";
+  }
+  var.name = key_name;
+
+  DCOUT("key: " << key_name << ", type: " << type_name);
+
  (*out_key) = key_name;
  (*out_var) = var;

@@ -2482,8 +2512,11 @@ bool AsciiParser::ParseDict(std::map<std::string, MetaVariable> *out_dict) {
        return false;
      }

-      assert(var.valid());
+      if (!var.valid()) {
+        PUSH_ERROR_AND_RETURN("Invalid Dict element(probably internal issue).");
+      }

+      DCOUT("Add to dict: " << key);
      (*out_dict)[key] = var;
    }
  }
@@ -3789,11 +3822,41 @@ bool AsciiParser::ParseMetaValue(const VariableDef &def,
    }
    DCOUT("bool = " << value);

+    var.value = value;
+  } else if (vartype == value::kToken) {
+
+    value::token value;
+    if (!ReadBasicType(&value)) {
+      std::string msg = "Token expected for `" + varname + "`.\n";
+      PushError(msg);
+      return false;
+    }
+    DCOUT("token = " << value);
+
+#if 0 // TODO
+    auto ret = def.post_parse_handler(value);
+    if (!ret) {
+      DCOUT("error = " << ret.error());
+      PUSH_ERROR_AND_RETURN("Invalid token for `" + varname + "`. " + ret.error());
+    }
+#endif
+
+    var.value = value;
+  } else if (vartype == "token[]") {
+
+    std::vector<value::token> value;
+    if (!ParseBasicTypeArray(&value)) {
+      std::string msg = "Token array expected for `" + varname + "`.\n";
+      PushError(msg);
+      return false;
+    }
+    // TODO
+    //DCOUT("token[] = " << to_string(value));
+
    var.value = value;
  } else if (vartype == value::kString) {

    std::string value;
-    DCOUT("parse meta = " << value);
    if (!ReadStringLiteral(&value)) {
      std::string msg = "String literal expected for `" + varname + "`.\n";
      PushError(msg);
@@ -3904,6 +3967,7 @@ bool AsciiParser::ParseMetaValue(const VariableDef &def,

    var.value = values;
  } else if (vartype == value::kDictionary) {
+#if 0
    DCOUT("dict type");
    if (!Expect('{')) {
      PushError("'{' expected.\n");
@@ -3935,10 +3999,20 @@ bool AsciiParser::ParseMetaValue(const VariableDef &def,
    }

    PUSH_WARN("TODO: Implement object type(customData)");
+#else
+    DCOUT("Parse dict in Prim meta.");
+    std::map<std::string, MetaVariable> dict;
+    if (!ParseDict(&dict)) {
+      PUSH_ERROR_AND_RETURN("Failed to parse `dictonary` in Prim meta.");
+    }
+    var.obj_value = dict;
+#endif
  } else {
    PUSH_ERROR_AND_RETURN("TODO: vartype = " + vartype);
  }

+  var.type = vartype;
+
  (*outvar) = var;

  return true;
@@ -4323,6 +4397,7 @@ AsciiParser::ParsePrimMeta() {
    PushError("Failed to parse Prim meta value.\n");
    return nonstd::nullopt;
  }
+  var.name = varname;

  return std::make_tuple(qual, var);
 }
@@ -4386,7 +4461,7 @@ bool AsciiParser::ParsePrimMetas(

    // ty = std::tuple<ListEditQual, MetaVariable>;
    if (auto m = ParsePrimMeta()) {
-      DCOUT("arg: list-edit qual = " << tinyusdz::to_string(std::get<0>(m.value()))
+      DCOUT("PrimMeta: list-edit qual = " << tinyusdz::to_string(std::get<0>(m.value()))
                                     << ", name = " << std::get<1>(m.value()).name);

      (*args)[std::get<1>(m.value()).name] = m.value();
@@ -5508,7 +5583,7 @@ bool AsciiParser::ParseDefBlock(const int64_t primIdx, const int64_t parentPrimI
    // DCOUT("`references.size` = " + std::to_string(references.size()));
  }

-#if 0
+#if 0 // TODO
  if (auto v = ReconstructPrimMetas(in_metas)) {
    DCOUT("TODO: ");
  } else {
@@ -5709,7 +5784,7 @@ bool AsciiParser::ParseDefBlock(const int64_t primIdx, const int64_t parentPrimI

    Path fullpath(GetCurrentPath(), "");
    Path pname(prim_name, "");
-    nonstd::expected<bool, std::string> ret = construct_fun(fullpath, pname, primIdx, parentPrimIdx, props, references);
+    nonstd::expected<bool, std::string> ret = construct_fun(fullpath, pname, primIdx, parentPrimIdx, props, references, in_metas);

    if (!ret) {
      // construction failed.
--- a/src/ascii-parser.hh
+++ b/src/ascii-parser.hh
@@ -5,11 +5,11 @@

 #pragma once

-#include <clocale>
 #include <functional>
 #include <stack>

-#include "external/better-enums/enum.h"
+//#include "external/better-enums/enum.h"
+#include "prim-types.hh"
 #include "stream-reader.hh"
 #include "tinyusdz.hh"

@@ -59,7 +59,7 @@ enum class LoadState {

 // Prim Kind
 // https://graphics.pixar.com/usd/release/glossary.html#usdglossary-kind
-#if 0
+#if 1
 enum class Kind {
  Model,  // "model"
  Group,  // "group"
@@ -89,6 +89,7 @@ bool IsUSDA(const std::string &filename, size_t max_filesize = 0);

 class AsciiParser {
 public:
+  // TODO: refactor
  struct PrimMetas {
    // Frequently used prim metas
    nonstd::optional<Kind> kind;
@@ -230,7 +231,10 @@ class AsciiParser {
  ///
  /// Prim Meta construction callback function
  ///
-  using PrimMetaProcessFunction = std::function<bool(const PrimMetas &metas)>;
+  //using PrimMetaProcessFunction = std::function<bool(const PrimMetas &metas)>;
+
+  using PrimMetaInput = std::map<std::string, std::tuple<ListEditQual, MetaVariable>>;
+

  ///
  /// Prim construction callback function
@@ -243,7 +247,7 @@ class AsciiParser {
      std::function<nonstd::expected<bool, std::string>(
          const Path &full_path, const Path &prim_name, const int64_t primIdx, const int64_t parentPrimIdx,
          const std::map<std::string, Property> &properties,
-          std::vector<std::pair<ListEditQual, Reference>> &references)>;
+          std::vector<std::pair<ListEditQual, Reference>> &references, const PrimMetaInput &in_meta)>;

  ///
  /// Register Prim construction callback function.
@@ -655,7 +659,7 @@ class AsciiParser {
  //
  PrimIdxAssignFunctin _prim_idx_assign_fun;
  StageMetaProcessFunction _stage_meta_process_fun;
-  PrimMetaProcessFunction _prim_meta_process_fun;
+  //PrimMetaProcessFunction _prim_meta_process_fun;
  std::map<std::string, PrimConstructFunction> _prim_construct_fun_map;
  std::map<std::string, PostPrimConstructFunction> _post_prim_construct_fun_map;

--- a/src/pprinter.cc
+++ b/src/pprinter.cc
@@ -129,8 +129,18 @@ std::string print_animatable(const Animatable<T> &v, const uint32_t indent = 0)
 std::string print_meta(const MetaVariable &meta, const uint32_t indent) {
  std::stringstream ss;

-  ss << pprint::Indent(indent) << meta.type << " " << meta.name;
-  ss << " [TODO]\n"; 
+  //ss << "TODO: isObject " << meta.IsObject() << ", isValue " << meta.IsValue() << "\n";
+
+  if (meta.IsObject()) {
+    // dict
+    ss << pprint::Indent(indent) << "dictionary " << meta.name << " {\n";
+    for (const auto &item : meta.obj_value) { 
+      ss << print_meta(item.second, indent+1);
+    }
+    ss << pprint::Indent(indent) << "}\n";
+  } else {
+    ss << pprint::Indent(indent) << meta.type << " " << meta.name << " = " << pprint_value(meta.value) << "\n";
+  }

  return ss.str();
 }
@@ -142,7 +152,7 @@ std::string print_customData(const CustomDataType &customData, const uint32_t in
  for (const auto &item : customData) {
    ss << print_meta(item.second, indent+1);
  }
-  ss << pprint::Indent(indent) << "\n}\n";
+  ss << pprint::Indent(indent) << "}\n";

  return ss.str();
 }
@@ -180,11 +190,10 @@ std::string print_attr_metas(const AttrMeta &meta, const uint32_t indent) {
  }

  if (meta.customData) {
-    ss << pprint::Indent(indent) << "customData = {\n";
-    ss << pprint::Indent(indent+1) << "TODO:\n";
-    ss << pprint::Indent(indent) << "}\n";
+    ss << print_customData(meta.customData.value(), indent);
  }

+  // other user defined metadataum.
  for (const auto &item : meta.meta) {
    ss << pprint::Indent(indent) << item.first << " = TODO\n";
  }
@@ -635,7 +644,7 @@ std::string to_string(const Xform &xform, const uint32_t indent, bool closing_br

  ss << pprint::Indent(indent) << "def Xform \"" << xform.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(xform.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -739,7 +748,9 @@ std::string to_string(const GeomMesh &mesh, const uint32_t indent, bool closing_

  ss << pprint::Indent(indent) << "def Mesh \"" << mesh.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  if (mesh.meta.authorized()) {
+    ss << print_prim_metas(mesh.meta, indent+1);
+  }
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -792,7 +803,7 @@ std::string to_string(const GeomSubset &geom, const uint32_t indent, bool closin

  ss << pprint::Indent(indent) << "def GeomSubset \"" << geom.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(geom.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -810,7 +821,7 @@ std::string to_string(const GeomPoints &geom, const uint32_t indent, bool closin

  ss << pprint::Indent(indent) << "def Points \"" << geom.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(geom.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -871,7 +882,7 @@ std::string to_string(const GeomBasisCurves &geom, const uint32_t indent, bool c

  ss << pprint::Indent(indent) << "def BasisCurves \"" << geom.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(geom.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -911,7 +922,7 @@ std::string to_string(const GeomCube &geom, const uint32_t indent, bool closing_

  ss << pprint::Indent(indent) << "def Cube \"" << geom.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(geom.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -932,7 +943,7 @@ std::string to_string(const GeomCone &geom, const uint32_t indent, bool closing_

  ss << pprint::Indent(indent) << "def Cone \"" << geom.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(geom.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -954,7 +965,7 @@ std::string to_string(const GeomCylinder &geom, const uint32_t indent, bool clos

  ss << pprint::Indent(indent) << "def Cylinder \"" << geom.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(geom.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -987,7 +998,7 @@ std::string to_string(const GeomCapsule &geom, const uint32_t indent, bool closi

  ss << pprint::Indent(indent) << "def Capsule \"" << geom.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(geom.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -1020,7 +1031,7 @@ std::string to_string(const SkelRoot &root, const uint32_t indent, bool closing_

  ss << pprint::Indent(indent) << "def SkelRoot \"" << root.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(root.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -1042,7 +1053,7 @@ std::string to_string(const Material &material, const uint32_t indent, bool clos

  ss << pprint::Indent(indent) << "def Material \"" << material.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  //print_prim_metas(material.metas, indent);
+  ss << print_prim_metas(material.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -1210,7 +1221,7 @@ std::string to_string(const Shader &shader, const uint32_t indent, bool closing_

    ss << pprint::Indent(indent) << "def Shader \"" << shader.name << "\"\n";
    ss << pprint::Indent(indent) << "(\n";
-    //print_prim_metas(shader.metas, indent);
+    ss << print_prim_metas(shader.meta, indent+1);
    ss << pprint::Indent(indent) << ")\n";
    ss << pprint::Indent(indent) << "{\n";

@@ -1243,7 +1254,7 @@ std::string to_string(const Skeleton &skel, const uint32_t indent, bool closing_

  ss << pprint::Indent(indent) << "def Skeleton \"" << skel.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(skel.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -1263,7 +1274,7 @@ std::string to_string(const LuxSphereLight &light, const uint32_t indent, bool c

  ss << pprint::Indent(indent) << "def SphereLight \"" << light.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(light.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

@@ -1285,7 +1296,7 @@ std::string to_string(const LuxDomeLight &light, const uint32_t indent, bool clo

  ss << pprint::Indent(indent) << "def DomeLight \"" << light.name << "\"\n";
  ss << pprint::Indent(indent) << "(\n";
-  // args
+  ss << print_prim_metas(light.meta, indent+1);
  ss << pprint::Indent(indent) << ")\n";
  ss << pprint::Indent(indent) << "{\n";

--- a/src/prim-types.hh
+++ b/src/prim-types.hh
@@ -755,6 +755,7 @@ class Connection
 };

 // Variable class for Prim and Attribute Metadataum.
+// TODO: use tiny-any
 class MetaVariable {
 public:
  std::string type;  // Explicit name of type
@@ -795,7 +796,7 @@ class MetaVariable {

    // infer type from value content
    if (v.IsObject()) {
-      return "dict";
+      return "dictionary";
    } else if (v.IsTimeSamples()) {
      std::string ts_type = "TODO: TimeSample typee";
      // FIXME
@@ -878,7 +879,7 @@ struct PrimMeta {

  std::map<std::string, MetaVariable> meta;  // other meta values

-  bool authorizerd() const {
+  bool authorized() const {
    return (kind || customData || meta.size());
  }

--- a/src/usdGeom.hh
+++ b/src/usdGeom.hh
@@ -57,6 +57,9 @@ struct GPrim {

  // child nodes
  std::vector<GPrim> children;
+
+  // Prim metadataum.
+  PrimMeta meta;
 };

 struct Xform : GPrim {
@@ -139,6 +142,7 @@ struct GeomSubset {
  std::vector<uint32_t> indices;

  std::map<std::string, Property> props;  // custom Properties
+  PrimMeta meta;
 };

 // Polygon mesh geometry
--- a/src/usdLux.hh
+++ b/src/usdLux.hh
@@ -41,6 +41,7 @@ struct LuxSphereLight {
  Purpose purpose{Purpose::Default};

  std::map<std::string, Property> props;
+  PrimMeta meta;
 };

 struct LuxDomeLight {
@@ -87,6 +88,7 @@ struct LuxDomeLight {
  std::vector<value::token> xformOpOrder;

  std::map<std::string, Property> props;
+  PrimMeta meta;
 };


--- a/src/usdShade.hh
+++ b/src/usdShade.hh
@@ -16,6 +16,8 @@ struct Material {

  int64_t parent_id{-1};

+  PrimMeta meta;
+
  Relation surface; // outputs:surface.connect
  Relation volume; // outputs:volume.connect

@@ -26,12 +28,16 @@ struct NodeGraph {
  std::string name;

  int64_t parent_id{-1};
+
+  PrimMeta meta;
 };

 template <typename T>
 struct UsdPrimvarReader {
  std::string name;

+  PrimMeta meta;
+
  nonstd::optional<T> fallback;  // "inputs:fallback"

  nonstd::optional<value::token> varname;  // "token inputs:varname". Name of the primvar to be fetched from the geometry("primvar" namespace is omitted).
@@ -101,6 +107,8 @@ struct UsdUVTexture {
  // Custom properties
  std::map<std::string, Property> props;

+  PrimMeta meta;
+
  // TODO: orientation?
  // https://graphics.pixar.com/usd/docs/UsdPreviewSurface-Proposal.html#UsdPreviewSurfaceProposal-TextureCoordinateOrientationinUSD
 };
@@ -146,6 +154,8 @@ struct UsdPreviewSurface {

  // Custom properties
  std::map<std::string, Property> props;
+
+  PrimMeta meta;
 };

 #if 0 // TODO: Move to Tydra
@@ -207,6 +217,8 @@ struct Shader {
                    PrimvarReader_float2>
      value;
 #endif
+
+  PrimMeta meta;
 };


--- a/src/usdSkel.hh
+++ b/src/usdSkel.hh
@@ -47,6 +47,8 @@ struct Skeleton {
  AnimatableVisibility visibility{Visibility::Inherited};

  std::vector<value::token> xformOpOrder;
+
+  PrimMeta meta;
 };

 struct SkelRoot {
@@ -64,6 +66,8 @@ struct SkelRoot {

  int64_t skeleton_id{-1};  // index to scene.skeletons
  // Skeleton skeleton;
+
+  PrimMeta meta;
 };

 struct SkelAnimation {
--- a/src/usda-reader.cc
+++ b/src/usda-reader.cc
@@ -413,7 +413,7 @@ class USDAReader::Impl {
        [&](const Path &full_path, const Path &prim_name, const int64_t primIdx,
            const int64_t parentPrimIdx,
            const std::map<std::string, Property> &properties,
-            const std::vector<std::pair<ListEditQual, Reference>> &references)
+            const std::vector<std::pair<ListEditQual, Reference>> &references, const ascii::AsciiParser::PrimMetaInput &in_meta)
            -> nonstd::expected<bool, std::string> {
          if (!prim_name.IsValid()) {
            return nonstd::make_unexpected("Invalid Prim name: " +
@@ -440,6 +440,11 @@ class USDAReader::Impl {

          T prim;

+          if (!ReconstructPrimMeta(in_meta, &prim.meta)) {
+            return nonstd::make_unexpected("Failed to process Prim metadataum.");
+          }
+
+
          DCOUT("primType = " << value::TypeTrait<T>::type_name()
                              << ", node.size "
                              << std::to_string(_prim_nodes.size())
@@ -538,6 +543,61 @@ class USDAReader::Impl {
    });
  }

+  bool ReconstructPrimMeta(
+    const ascii::AsciiParser::PrimMetaInput &in_meta,
+    PrimMeta *out) {
+
+    DCOUT("ReconstructPrimMeta");
+    for (const auto &meta : in_meta) {
+      DCOUT("meta.name = " << meta.first);
+
+      if (meta.first == "kind") {
+        // std::tuple<ListEditQual, MetaVariable>
+        // TODO: list-edit qual
+        const MetaVariable &var = std::get<1>(meta.second);
+        DCOUT("kind. type = " << var.type);
+        if (var.type == "token") {
+          if (auto pv = var.value.get_value<value::token>()) {
+            const value::token tok = pv.value();
+            if (tok.str() == "subcomponent") {
+              out->kind = Kind::Subcomponent;
+            } else if (tok.str() == "component") {
+              out->kind = Kind::Component;
+            } else if (tok.str() == "model") {
+              out->kind = Kind::Model;
+            } else if (tok.str() == "group") {
+              out->kind = Kind::Group;
+            } else if (tok.str() == "assembly") {
+              out->kind = Kind::Assembly;
+            } else {
+              PUSH_ERROR_AND_RETURN("Invalid token for `kind` metadataum.");
+            }
+            DCOUT("Added kind: " << to_string(out->kind.value()));
+          } else {
+            PUSH_ERROR_AND_RETURN("(Internal error?) `kind` metadataum is not type `token`.");
+          }
+        } else {
+          PUSH_ERROR_AND_RETURN("(Internal error?) `kind` metadataum is not type `token`. got `" << var.type << "`.");
+        }
+      } else if (meta.first == "customData") {
+        const MetaVariable &var = std::get<1>(meta.second);
+        DCOUT("customData. type = " << var.type);
+        if (var.type == "dictionary") {
+          CustomDataType customData;
+          customData = var.obj_value;
+          DCOUT("dict size = " << var.obj_value.size());
+          out->customData = customData;
+        } else {
+          PUSH_ERROR_AND_RETURN("(Internal error?) `customData` metadataum is not type `dictionary`. got type `" << var.type << "`\n");
+        }
+      } else {
+        PUSH_WARN("TODO: Prim metadataum : " << meta.first);
+      }
+    }
+
+    return true;
+  }
+
  ///
  /// Reader entry point
  /// TODO: Use callback function(visitor) so that Reconstruct**** function is
@@ -1246,7 +1306,7 @@ bool USDAReader::Impl::RegisterReconstructCallback<GeomSubset>() {
      [&](const Path &full_path, const Path &prim_name, const int64_t primIdx,
          const int64_t parentPrimIdx,
          const std::map<std::string, Property> &properties,
-          std::vector<std::pair<ListEditQual, Reference>> &references)
+          const std::vector<std::pair<ListEditQual, Reference>> &references, const ascii::AsciiParser::PrimMetaInput &in_meta)
          -> nonstd::expected<bool, std::string> {

        const Path& parent = full_path.GetParentPrim();
@@ -1269,6 +1329,11 @@ bool USDAReader::Impl::RegisterReconstructCallback<GeomSubset>() {
              "Unexpected parentPrimIdx for GeomSubset.");
        }

+        PrimMeta meta;
+        if (!ReconstructPrimMeta(in_meta, &meta)) {
+          return nonstd::make_unexpected("Failed to process Prim metadataum.");
+        }
+
        // TODO: Construct GeomMesh first
 #if 0
        const std::string parent_primpath = parent.GetPrimPart();
@@ -1443,6 +1508,7 @@ bool USDAReader::Impl::RegisterReconstructCallback<GeomSubset>() {
        }

        subset.name = prim_name.GetPrimPart();
+        subset.meta = meta;

        // Add to scene graph.
        // NOTE: Scene graph is constructed from bottom up manner(Children
--- a/tests/usda/customData-prim.usda
+++ b/tests/usda/customData-prim.usda
@@ -0,0 +1,21 @@
+#usda 1.0
+
+def Xform "teapot" (
+    kind = "component"
+)
+{
+    def Mesh "Teapot" (
+        customData = {
+            bool zUp = 1
+            dictionary Maya = {
+                bool generated = 1
+            }
+        }
+    )
+    {
+
+        color3f[] primvars:displayColor = [(1, 1, 1)] (
+        )
+
+    }
+}