feat: add validator SkelBindingAPIAppliedChecker

pxr/usd/usdSkel/CMakeLists.txt

@@ -37,6 +37,10 @@ pxr_library(usdSkel
         tokens
         topology
         utils
+        validatorTokens
+
+    CPPFILES
+        validators.cpp
 
     PUBLIC_HEADERS
         api.h
@@ -93,6 +97,15 @@ pxr_library(usdSkel
         images/influencesPrimvarLayout.svg
         images/unboundedInterpolationExample.svg
 )
+
+pxr_build_test(testUsdSkelValidators
+    LIBRARIES
+    tf
+    usd
+    usdSkel
+    CPPFILES
+    testenv/testUsdSkelValidators.cpp
+)
 
 pxr_test_scripts(
     testenv/testUsdSkelAnimMapper.py
@@ -189,3 +202,9 @@ pxr_register_test(testUsdSkelUtils
     COMMAND "${CMAKE_INSTALL_PREFIX}/tests/testUsdSkelUtils"
     EXPECTED_RETURN_CODE 0
 )
+
+pxr_register_test(testUsdSkelValidators
+    COMMAND "${CMAKE_INSTALL_PREFIX}/tests/testUsdSkelValidators"
+    EXPECTED_RETURN_CODE 0
+)
+

pxr/usd/usdSkel/plugInfo.json

@@ -69,6 +69,14 @@
                         "implementsComputeExtent": true, 
                         "schemaKind": "concreteTyped"
                     }
+                },
+                "Validators": {
+                    "SkelBindingApiAppliedValidator": {
+                        "doc": "Verify a prim has the SkelBindingAPI applied if it has a UsdSkelBinding property. If a prim has the SkelBindingAPI applied, make sure it's of type SkelRoot or parented by a SkelRoot."
+                    },
+                    "keywords": [
+                        "UsdSkelValidators"
+                    ]
                 }
             }, 
             "LibraryPath": "@PLUG_INFO_LIBRARY_PATH@", 

pxr/usd/usdSkel/testenv/testUsdSkelValidators.cpp

@@ -0,0 +1,107 @@
+//
+// Copyright 2024 Pixar
+//
+// Licensed under the terms set forth in the LICENSE.txt file available at
+// https://openusd.org/license.
+//
+#include "pxr/usd/usd/validationRegistry.h"
+#include "pxr/usd/usd/validationError.h"
+#include <pxr/usd/usdSkel/validatorTokens.h>
+#include <pxr/usd/usdSkel/root.h>
+#include <pxr/usd/usdSkel/bindingAPI.h>
+#include <pxr/usd/usdGeom/mesh.h>
+#include <pxr/usd/usdGeom/primvarsAPI.h>
+
+PXR_NAMESPACE_USING_DIRECTIVE
+
+void
+TestUsdSkelValidators()
+{
+    // This should be updated with every new validator added with
+    // UsdSkelValidators keyword.
+    UsdValidationRegistry &registry = UsdValidationRegistry::GetInstance();
+    UsdValidatorMetadataVector metadata =
+            registry.GetValidatorMetadataForKeyword(
+                    UsdSkelValidatorKeywordTokens->UsdSkelValidators);
+    // Since other validators can be registered with a UsdSkelValidators
+    // keyword, our validators registered in usdSkel are a subset of the entire
+    // set.
+    std::set<TfToken> validatorMetadataNameSet;
+    for (const UsdValidatorMetadata &metadata : metadata) {
+        validatorMetadataNameSet.insert(metadata.name);
+    }
+
+    const std::set<TfToken> expectedValidatorNames =
+            {UsdSkelValidatorNameTokens->skelBindingApiAppliedValidator};
+
+    TF_AXIOM(std::includes(validatorMetadataNameSet.begin(),
+                           validatorMetadataNameSet.end(),
+                           expectedValidatorNames.begin(),
+                           expectedValidatorNames.end()));
+}
+
+void
+TestUsdSkelBindingApiAppliedValidator()
+{
+    // Verify that the validator exists.
+    UsdValidationRegistry &registry = UsdValidationRegistry::GetInstance();
+    const UsdValidator *validator = registry.GetOrLoadValidatorByName(
+            UsdSkelValidatorNameTokens->skelBindingApiAppliedValidator);
+    TF_AXIOM(validator);
+
+    // Create Stage and mesh with a skel binding property
+    UsdStageRefPtr usdStage = UsdStage::CreateInMemory();
+    UsdGeomMesh mesh = UsdGeomMesh::Define(usdStage, SdfPath("/SkelRoot/Mesh"));
+    UsdGeomPrimvarsAPI primvarsApi(mesh);
+    UsdGeomPrimvar jointIndicesPrimvar = primvarsApi.CreatePrimvar(TfToken("skel:jointIndices"), SdfValueTypeNames->IntArray, UsdGeomTokens->vertex);
+    jointIndicesPrimvar.Set(VtIntArray{0, 1, 2});
+
+    UsdValidationErrorVector errors = validator->Validate(mesh.GetPrim());
+
+    // Verify the error for not having the SkelBindingAPI schema applied is present.
+    TF_AXIOM(errors.size() == 1);
+    TF_AXIOM(errors[0].GetType() == UsdValidationErrorType::Error);
+    TF_AXIOM(errors[0].GetSites().size() == 1);
+    TF_AXIOM(errors[0].GetSites()[0].IsValid());
+    TF_AXIOM(errors[0].GetSites()[0].IsPrim());
+    TF_AXIOM(errors[0].GetSites()[0].GetPrim().GetPath() ==
+             SdfPath("/SkelRoot/Mesh"));
+    std::string expectedErrorMsg = ("Found a UsdSkelBinding property (primvars:skel:jointIndices)"
+                                    ", but no SkelBindingAPI applied on the prim </SkelRoot/Mesh>.");
+    TF_AXIOM(errors[0].GetMessage() == expectedErrorMsg);
+
+    // Apply the SkelBindingAPI.
+    UsdSkelBindingAPI skelBindingApi = UsdSkelBindingAPI::Apply(mesh.GetPrim());
+
+    errors = validator->Validate(mesh.GetPrim());
+
+    // Verify the error for not having a SkelRoot parenting a prim with the SkelBindingAPI applied.
+    TF_AXIOM(errors.size() == 1);
+    TF_AXIOM(errors[0].GetType() == UsdValidationErrorType::Error);
+    TF_AXIOM(errors[0].GetSites().size() == 1);
+    TF_AXIOM(errors[0].GetSites()[0].IsValid());
+    TF_AXIOM(errors[0].GetSites()[0].IsPrim());
+    TF_AXIOM(errors[0].GetSites()[0].GetPrim().GetPath() ==
+             SdfPath("/SkelRoot/Mesh"));
+    expectedErrorMsg = ("UsdSkelBindingAPI applied on prim: </SkelRoot/Mesh>, "
+                "which is not of type SkelRoot or is not rooted at a prim "
+                "of type SkelRoot, as required by the UsdSkel schema.");
+    const std::string message = errors[0].GetMessage();
+    TF_AXIOM(errors[0].GetMessage() == expectedErrorMsg);
+
+    // Add SkelRoot as a parent to the mesh.
+    UsdSkelRoot skelRoot = UsdSkelRoot::Define(usdStage, SdfPath("/SkelRoot"));
+    errors = validator->Validate(mesh.GetPrim());
+
+    // Verify all errors are gone
+    TF_AXIOM(errors.size() == 0);
+}
+
+int
+main()
+{
+    TestUsdSkelValidators();
+    TestUsdSkelBindingApiAppliedValidator();
+    printf("OK\n");
+    return EXIT_SUCCESS;
+};

pxr/usd/usdSkel/validatorTokens.cpp

@@ -0,0 +1,17 @@
+//
+// Copyright 2024 Pixar
+//
+// Licensed under the terms set forth in the LICENSE.txt file available at
+// https://openusd.org/license.
+//
+
+#include "pxr/usd/usdSkel/validatorTokens.h"
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+TF_DEFINE_PUBLIC_TOKENS(UsdSkelValidatorNameTokens,
+                        USD_SKEL_VALIDATOR_NAME_TOKENS);
+TF_DEFINE_PUBLIC_TOKENS(UsdSkelValidatorKeywordTokens,
+                        USD_SKEL_VALIDATOR_KEYWORD_TOKENS);
+
+PXR_NAMESPACE_CLOSE_SCOPE

pxr/usd/usdSkel/validatorTokens.h

@@ -0,0 +1,34 @@
+//
+// Copyright 2024 Pixar
+//
+// Licensed under the terms set forth in the LICENSE.txt file available at
+// https://openusd.org/license.
+//
+#ifndef USDSKEL_VALIDATOR_TOKENS_H
+#define USDSKEL_VALIDATOR_TOKENS_H
+/// \file
+#include "pxr/pxr.h"
+#include "pxr/usd/usdSkel/api.h"
+#include "pxr/base/tf/staticTokens.h"
+PXR_NAMESPACE_OPEN_SCOPE
+
+#define USD_SKEL_VALIDATOR_NAME_TOKENS                   \
+     ((skelBindingApiAppliedValidator, "usdSkel:SkelBindingApiAppliedValidator"))
+#define USD_SKEL_VALIDATOR_KEYWORD_TOKENS                \
+     (UsdSkelValidators)
+
+///\def
+/// Tokens representing validator names. Note that for plugin provided
+/// validators, the names must be prefixed by usdSkel:, which is the name of
+/// the usdSkel plugin.
+TF_DECLARE_PUBLIC_TOKENS(UsdSkelValidatorNameTokens, USDSKEL_API,
+                         USD_SKEL_VALIDATOR_NAME_TOKENS);
+///\def
+/// Tokens representing keywords associated with any validator in the usdShade
+/// plugin. Clients can use this to inspect validators contained within a
+/// specific keywords, or use these to be added as keywords to any new
+/// validator.
+TF_DECLARE_PUBLIC_TOKENS(UsdSkelValidatorKeywordTokens, USDSKEL_API,
+                         USD_SKEL_VALIDATOR_KEYWORD_TOKENS);
+PXR_NAMESPACE_CLOSE_SCOPE
+#endif

pxr/usd/usdSkel/validators.cpp

@@ -0,0 +1,89 @@
+//
+// Copyright 2024 Pixar
+//
+// Licensed under the terms set forth in the LICENSE.txt file available at
+// https://openusd.org/license.
+//
+#include "pxr/usd/usd/prim.h"
+#include "pxr/usd/usd/schemaRegistry.h"
+#include "pxr/usd/usd/validationError.h"
+#include "pxr/usd/usd/validationRegistry.h"
+#include "pxr/usd/usd/validator.h"
+#include "pxr/base/tf/token.h"
+#include "pxr/base/tf/stringUtils.h"
+#include "pxr/usd/usdSkel/validatorTokens.h"
+#include "pxr/usd/usdSkel/bindingAPI.h"
+
+#include <algorithm>
+#include <unordered_map>
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+static
+UsdValidationErrorVector
+_SkelBindingApiAppliedValidator(const UsdPrim &usdPrim)
+{
+    UsdValidationErrorVector errors;
+
+    if (!usdPrim.HasAPI<UsdSkelBindingAPI>()){
+        std::vector<TfToken> primPropertyNames = usdPrim.GetPropertyNames();
+        static const std::unordered_set<TfToken, TfHash> skelPropertyNames = []() {
+            UsdSchemaRegistry& usdSchemaRegistry = UsdSchemaRegistry::GetInstance();
+            std::unique_ptr<UsdPrimDefinition> primDef = usdSchemaRegistry.BuildComposedPrimDefinition(TfToken(), {TfToken("SkelBindingAPI")});
+            std::vector<TfToken> vectorOfNames = primDef->GetPropertyNames();
+            return std::unordered_set<TfToken, TfHash>(vectorOfNames.begin(), vectorOfNames.end());
+        }();
+
+        for (const TfToken &primToken : primPropertyNames){
+            if (skelPropertyNames.find(primToken) == skelPropertyNames.end()){
+                continue;
+            }
+            errors.emplace_back(
+                    UsdValidationErrorType::Error,
+                    UsdValidationErrorSites{
+                            UsdValidationErrorSite(usdPrim.GetStage(),
+                                                   usdPrim.GetPath())
+                    },
+                    TfStringPrintf(("Found a UsdSkelBinding property (%s), "
+                                    "but no SkelBindingAPI applied on the prim <%s>."),
+                                   primToken.GetText(), usdPrim.GetPath().GetText()));
+            break;
+        }
+    }
+    else {
+        if (usdPrim.GetTypeName() != UsdSkelTokens->SkelRoot) {
+            UsdPrim parentPrim = usdPrim.GetParent();
+            while (parentPrim && !parentPrim.IsPseudoRoot()) {
+                if (parentPrim.GetTypeName() != UsdSkelTokens->SkelRoot) {
+                    parentPrim = parentPrim.GetParent();
+                }
+                else {
+                    return errors;
+                }
+            }
+            errors.emplace_back(
+                    UsdValidationErrorType::Error,
+                    UsdValidationErrorSites{
+                            UsdValidationErrorSite(usdPrim.GetStage(),
+                                                   usdPrim.GetPath())
+                    },
+                    TfStringPrintf(("UsdSkelBindingAPI applied on prim: <%s>, "
+                            "which is not of type SkelRoot or is not rooted at a prim "
+                            "of type SkelRoot, as required by the UsdSkel schema."),
+                                   usdPrim.GetPath().GetText()));
+        }
+    }
+
+    return errors;
+}
+
+TF_REGISTRY_FUNCTION(UsdValidationRegistry)
+{
+    UsdValidationRegistry &registry = UsdValidationRegistry::GetInstance();
+
+    registry.RegisterPluginValidator(
+            UsdSkelValidatorNameTokens->skelBindingApiAppliedValidator,
+            _SkelBindingApiAppliedValidator);
+}
+
+PXR_NAMESPACE_CLOSE_SCOPE