Update provided kernel list after discussing with Vincent from NVIDIA.

Author: ld-kerley

pxr/usd/usdLightField/generatedSchema.classes.txt

@@ -2,14 +2,15 @@
 
 # Public Classes
 kernelBaseAPI
-kernelConstantTriangleAPI
+kernelConstantSurfletAPI
 kernelGaussianEllipsoidAPI
-kernelGaussianTriangleAPI
+kernelGaussianSurfletAPI
 opacityAttributeAPI
 orientationAttributeAPI
 particleField
 particleField_3DGaussianSplat
 positionAttributeAPI
+positionBaseAPI
 radianceBaseAPI
 scaleAttributeAPI
 sphericalBetaAttributeAPI
@@ -19,14 +20,15 @@ tokens
 # Python Module Files
 module.cpp
 wrapKernelBaseAPI.cpp
-wrapKernelConstantTriangleAPI.cpp
+wrapKernelConstantSurfletAPI.cpp
 wrapKernelGaussianEllipsoidAPI.cpp
-wrapKernelGaussianTriangleAPI.cpp
+wrapKernelGaussianSurfletAPI.cpp
 wrapOpacityAttributeAPI.cpp
 wrapOrientationAttributeAPI.cpp
 wrapParticleField.cpp
 wrapParticleField_3DGaussianSplat.cpp
 wrapPositionAttributeAPI.cpp
+wrapPositionBaseAPI.cpp
 wrapRadianceBaseAPI.cpp
 wrapScaleAttributeAPI.cpp
 wrapSphericalBetaAttributeAPI.cpp

pxr/usd/usdLightField/generatedSchema.module.h

@@ -8,14 +8,15 @@
 // WARNING: THIS FILE IS GENERATED BY usdGenSchema.  DO NOT EDIT.
 TF_WRAP(UsdLightFieldParticleField);
 TF_WRAP(UsdLightFieldParticleField_3DGaussianSplat);
+TF_WRAP(UsdLightFieldPositionBaseAPI);
 TF_WRAP(UsdLightFieldPositionAttributeAPI);
 TF_WRAP(UsdLightFieldOrientationAttributeAPI);
 TF_WRAP(UsdLightFieldScaleAttributeAPI);
 TF_WRAP(UsdLightFieldOpacityAttributeAPI);
 TF_WRAP(UsdLightFieldKernelBaseAPI);
 TF_WRAP(UsdLightFieldKernelGaussianEllipsoidAPI);
-TF_WRAP(UsdLightFieldKernelGaussianTriangleAPI);
-TF_WRAP(UsdLightFieldKernelConstantTriangleAPI);
+TF_WRAP(UsdLightFieldKernelGaussianSurfletAPI);
+TF_WRAP(UsdLightFieldKernelConstantSurfletAPI);
 TF_WRAP(UsdLightFieldRadianceBaseAPI);
 TF_WRAP(UsdLightFieldSphericalHarmonicsAttributeAPI);
 TF_WRAP(UsdLightFieldSphericalBetaAttributeAPI);

pxr/usd/usdLightField/generatedSchema.usda

@@ -81,7 +81,17 @@ class ParticleField "ParticleField" (
     )
 }
 
+class "LightFieldPositionBaseAPI" (
+    customData = {
+        string userDocBrief = """Defines a base-class type applied schema that all applied schema
+            that provides the a ParticleField kernel will automatically apply."""
+    }
+)
+{
+}
+
 class "LightFieldPositionAttributeAPI" (
+    apiSchemas = ["LightFieldPositionBaseAPI"]
     customData = {
         string userDocBrief = """A ParticleField related applied schema that provides a position
              attribute to define the locations of the particles."""
@@ -177,25 +187,19 @@ class "LightFieldKernelGaussianEllipsoidAPI" (
 {
 }
 
-class "LightFieldKernelGaussianTriangleAPI" (
+class "LightFieldKernelGaussianSurfletAPI" (
     apiSchemas = ["LightFieldKernelBaseAPI"]
     customData = {
-        string userDocBrief = "Defines the gaussian triangle kernel for a given ParticleField."
+        string userDocBrief = "Defines the gaussian surflet kernel for a given ParticleField."
     }
 )
 {
-    float kernel:triangle:edgeLength = 1 (
-        customData = {
-            string userDocBrief = """The edge length of the equilateral triangle before any scaling
-                is applied."""
-        }
-    )
 }
 
-class "LightFieldKernelConstantTriangleAPI" (
+class "LightFieldKernelConstantSurfletAPI" (
     apiSchemas = ["LightFieldKernelBaseAPI"]
     customData = {
-        string userDocBrief = "Defines the gaussian triangle kernel for a given ParticleField."
+        string userDocBrief = "Defines the constant surflet kernel for a given ParticleField."
     }
 )
 {

pxr/usd/usdLightField/kernelConstantTriangleAPI.cpp renamed to pxr/usd/usdLightField/kernelConstantSurfletAPI.cpp

@@ -4,7 +4,7 @@
 // Licensed under the terms set forth in the LICENSE.txt file available at
 // https://openusd.org/license.
 //
-#include "pxr/usd/usdLightField/kernelConstantTriangleAPI.h"
+#include "pxr/usd/usdLightField/kernelConstantSurfletAPI.h"
 #include "pxr/usd/usd/schemaRegistry.h"
 #include "pxr/usd/usd/typed.h"
 
@@ -16,78 +16,78 @@ PXR_NAMESPACE_OPEN_SCOPE
 // Register the schema with the TfType system.
 TF_REGISTRY_FUNCTION(TfType)
 {
-    TfType::Define<UsdLightFieldKernelConstantTriangleAPI,
+    TfType::Define<UsdLightFieldKernelConstantSurfletAPI,
         TfType::Bases< UsdAPISchemaBase > >();
 
 }
 
 /* virtual */
-UsdLightFieldKernelConstantTriangleAPI::~UsdLightFieldKernelConstantTriangleAPI()
+UsdLightFieldKernelConstantSurfletAPI::~UsdLightFieldKernelConstantSurfletAPI()
 {
 }
 
 /* static */
-UsdLightFieldKernelConstantTriangleAPI
-UsdLightFieldKernelConstantTriangleAPI::Get(const UsdStagePtr &stage, const SdfPath &path)
+UsdLightFieldKernelConstantSurfletAPI
+UsdLightFieldKernelConstantSurfletAPI::Get(const UsdStagePtr &stage, const SdfPath &path)
 {
     if (!stage) {
         TF_CODING_ERROR("Invalid stage");
-        return UsdLightFieldKernelConstantTriangleAPI();
+        return UsdLightFieldKernelConstantSurfletAPI();
     }
-    return UsdLightFieldKernelConstantTriangleAPI(stage->GetPrimAtPath(path));
+    return UsdLightFieldKernelConstantSurfletAPI(stage->GetPrimAtPath(path));
 }
 
 
 /* virtual */
-UsdSchemaKind UsdLightFieldKernelConstantTriangleAPI::_GetSchemaKind() const
+UsdSchemaKind UsdLightFieldKernelConstantSurfletAPI::_GetSchemaKind() const
 {
-    return UsdLightFieldKernelConstantTriangleAPI::schemaKind;
+    return UsdLightFieldKernelConstantSurfletAPI::schemaKind;
 }
 
 /* static */
 bool
-UsdLightFieldKernelConstantTriangleAPI::CanApply(
+UsdLightFieldKernelConstantSurfletAPI::CanApply(
     const UsdPrim &prim, std::string *whyNot)
 {
-    return prim.CanApplyAPI<UsdLightFieldKernelConstantTriangleAPI>(whyNot);
+    return prim.CanApplyAPI<UsdLightFieldKernelConstantSurfletAPI>(whyNot);
 }
 
 /* static */
-UsdLightFieldKernelConstantTriangleAPI
-UsdLightFieldKernelConstantTriangleAPI::Apply(const UsdPrim &prim)
+UsdLightFieldKernelConstantSurfletAPI
+UsdLightFieldKernelConstantSurfletAPI::Apply(const UsdPrim &prim)
 {
-    if (prim.ApplyAPI<UsdLightFieldKernelConstantTriangleAPI>()) {
-        return UsdLightFieldKernelConstantTriangleAPI(prim);
+    if (prim.ApplyAPI<UsdLightFieldKernelConstantSurfletAPI>()) {
+        return UsdLightFieldKernelConstantSurfletAPI(prim);
     }
-    return UsdLightFieldKernelConstantTriangleAPI();
+    return UsdLightFieldKernelConstantSurfletAPI();
 }
 
 /* static */
 const TfType &
-UsdLightFieldKernelConstantTriangleAPI::_GetStaticTfType()
+UsdLightFieldKernelConstantSurfletAPI::_GetStaticTfType()
 {
-    static TfType tfType = TfType::Find<UsdLightFieldKernelConstantTriangleAPI>();
+    static TfType tfType = TfType::Find<UsdLightFieldKernelConstantSurfletAPI>();
     return tfType;
 }
 
 /* static */
 bool 
-UsdLightFieldKernelConstantTriangleAPI::_IsTypedSchema()
+UsdLightFieldKernelConstantSurfletAPI::_IsTypedSchema()
 {
     static bool isTyped = _GetStaticTfType().IsA<UsdTyped>();
     return isTyped;
 }
 
 /* virtual */
 const TfType &
-UsdLightFieldKernelConstantTriangleAPI::_GetTfType() const
+UsdLightFieldKernelConstantSurfletAPI::_GetTfType() const
 {
     return _GetStaticTfType();
 }
 
 /*static*/
 const TfTokenVector&
-UsdLightFieldKernelConstantTriangleAPI::GetSchemaAttributeNames(bool includeInherited)
+UsdLightFieldKernelConstantSurfletAPI::GetSchemaAttributeNames(bool includeInherited)
 {
     static TfTokenVector localNames;
     static TfTokenVector allNames =
@@ -100,7 +100,7 @@ UsdLightFieldKernelConstantTriangleAPI::GetSchemaAttributeNames(bool includeInhe
 }
 
 UsdLightFieldKernelBaseAPI
-UsdLightFieldKernelConstantTriangleAPI::LightFieldKernelBaseAPI() const
+UsdLightFieldKernelConstantSurfletAPI::LightFieldKernelBaseAPI() const
 {
     return UsdLightFieldKernelBaseAPI(GetPrim());
 }

pxr/usd/usdLightField/kernelConstantTriangleAPI.h renamed to pxr/usd/usdLightField/kernelConstantSurfletAPI.h

@@ -4,10 +4,10 @@
 // Licensed under the terms set forth in the LICENSE.txt file available at
 // https://openusd.org/license.
 //
-#ifndef USDLIGHTFIELD_GENERATED_KERNELCONSTANTTRIANGLEAPI_H
-#define USDLIGHTFIELD_GENERATED_KERNELCONSTANTTRIANGLEAPI_H
+#ifndef USDLIGHTFIELD_GENERATED_KERNELCONSTANTSURFLETAPI_H
+#define USDLIGHTFIELD_GENERATED_KERNELCONSTANTSURFLETAPI_H
 
-/// \file usdLightField/kernelConstantTriangleAPI.h
+/// \file usdLightField/kernelConstantSurfletAPI.h
 
 #include "pxr/pxr.h"
 #include "pxr/usd/usdLightField/api.h"
@@ -32,48 +32,47 @@ PXR_NAMESPACE_OPEN_SCOPE
 class SdfAssetPath;
 
 // -------------------------------------------------------------------------- //
-// LIGHTFIELDKERNELCONSTANTTRIANGLEAPI                                        //
+// LIGHTFIELDKERNELCONSTANTSURFLETAPI                                         //
 // -------------------------------------------------------------------------- //
 
-/// \class UsdLightFieldKernelConstantTriangleAPI
+/// \class UsdLightFieldKernelConstantSurfletAPI
 ///
-/// Defines the gaussian triangle kernel for a given ParticleField.
+/// Defines the constant surflet kernel for a given ParticleField.
 /// 
-/// The kernal shape is an equilateral triangle centered at the origin, with
-/// the base of the triangle, parallel to the x-axis, and the apex of the
-/// triangle on the y-axis.
+/// The kernal shape is a circular disk centered at the origin, with the normal
+/// of the plane being oriented along the positive z-axis.
 /// 
 /// The falloff function for this kernel is constant and the value is directly
 /// defined by the opacity data source.
 ///
-class UsdLightFieldKernelConstantTriangleAPI : public UsdAPISchemaBase
+class UsdLightFieldKernelConstantSurfletAPI : public UsdAPISchemaBase
 {
 public:
     /// Compile time constant representing what kind of schema this class is.
     ///
     /// \sa UsdSchemaKind
     static const UsdSchemaKind schemaKind = UsdSchemaKind::SingleApplyAPI;
 
-    /// Construct a UsdLightFieldKernelConstantTriangleAPI on UsdPrim \p prim .
-    /// Equivalent to UsdLightFieldKernelConstantTriangleAPI::Get(prim.GetStage(), prim.GetPath())
+    /// Construct a UsdLightFieldKernelConstantSurfletAPI on UsdPrim \p prim .
+    /// Equivalent to UsdLightFieldKernelConstantSurfletAPI::Get(prim.GetStage(), prim.GetPath())
     /// for a \em valid \p prim, but will not immediately throw an error for
     /// an invalid \p prim
-    explicit UsdLightFieldKernelConstantTriangleAPI(const UsdPrim& prim=UsdPrim())
+    explicit UsdLightFieldKernelConstantSurfletAPI(const UsdPrim& prim=UsdPrim())
         : UsdAPISchemaBase(prim)
     {
     }
 
-    /// Construct a UsdLightFieldKernelConstantTriangleAPI on the prim held by \p schemaObj .
-    /// Should be preferred over UsdLightFieldKernelConstantTriangleAPI(schemaObj.GetPrim()),
+    /// Construct a UsdLightFieldKernelConstantSurfletAPI on the prim held by \p schemaObj .
+    /// Should be preferred over UsdLightFieldKernelConstantSurfletAPI(schemaObj.GetPrim()),
     /// as it preserves SchemaBase state.
-    explicit UsdLightFieldKernelConstantTriangleAPI(const UsdSchemaBase& schemaObj)
+    explicit UsdLightFieldKernelConstantSurfletAPI(const UsdSchemaBase& schemaObj)
         : UsdAPISchemaBase(schemaObj)
     {
     }
 
     /// Destructor.
     USDLIGHTFIELD_API
-    virtual ~UsdLightFieldKernelConstantTriangleAPI();
+    virtual ~UsdLightFieldKernelConstantSurfletAPI();
 
     /// Return a vector of names of all pre-declared attributes for this schema
     /// class and all its ancestor classes.  Does not include attributes that
@@ -82,17 +81,17 @@ class UsdLightFieldKernelConstantTriangleAPI : public UsdAPISchemaBase
     static const TfTokenVector &
     GetSchemaAttributeNames(bool includeInherited=true);
 
-    /// Return a UsdLightFieldKernelConstantTriangleAPI holding the prim adhering to this
+    /// Return a UsdLightFieldKernelConstantSurfletAPI holding the prim adhering to this
     /// schema at \p path on \p stage.  If no prim exists at \p path on
     /// \p stage, or if the prim at that path does not adhere to this schema,
     /// return an invalid schema object.  This is shorthand for the following:
     ///
     /// \code
-    /// UsdLightFieldKernelConstantTriangleAPI(stage->GetPrimAtPath(path));
+    /// UsdLightFieldKernelConstantSurfletAPI(stage->GetPrimAtPath(path));
     /// \endcode
     ///
     USDLIGHTFIELD_API
-    static UsdLightFieldKernelConstantTriangleAPI
+    static UsdLightFieldKernelConstantSurfletAPI
     Get(const UsdStagePtr &stage, const SdfPath &path);
 
 
@@ -117,11 +116,11 @@ class UsdLightFieldKernelConstantTriangleAPI : public UsdAPISchemaBase
     CanApply(const UsdPrim &prim, std::string *whyNot=nullptr);
 
     /// Applies this <b>single-apply</b> API schema to the given \p prim.
-    /// This information is stored by adding "LightFieldKernelConstantTriangleAPI" to the 
+    /// This information is stored by adding "LightFieldKernelConstantSurfletAPI" to the 
     /// token-valued, listOp metadata \em apiSchemas on the prim.
     /// 
-    /// \return A valid UsdLightFieldKernelConstantTriangleAPI object is returned upon success. 
-    /// An invalid (or empty) UsdLightFieldKernelConstantTriangleAPI object is returned upon 
+    /// \return A valid UsdLightFieldKernelConstantSurfletAPI object is returned upon success. 
+    /// An invalid (or empty) UsdLightFieldKernelConstantSurfletAPI object is returned upon 
     /// failure. See \ref UsdPrim::ApplyAPI() for conditions 
     /// resulting in failure. 
     /// 
@@ -132,7 +131,7 @@ class UsdLightFieldKernelConstantTriangleAPI : public UsdAPISchemaBase
     /// \sa UsdPrim::RemoveAPI()
     ///
     USDLIGHTFIELD_API
-    static UsdLightFieldKernelConstantTriangleAPI 
+    static UsdLightFieldKernelConstantSurfletAPI 
     Apply(const UsdPrim &prim);
 
 protected:

pxr/usd/usdLightField/kernelGaussianEllipsoidAPI.h

@@ -39,7 +39,7 @@ class SdfAssetPath;
 ///
 /// Defines the gaussian ellipsoid kernel for a given ParticleField.
 /// 
-/// The kernel shape is a circular region that is reshaped by the associated
+/// The kernel shape is a spherical region that is reshaped by the associated
 /// scale data source, and rotated by the orientation data source.
 /// 
 /// The falloff function for this kernel is the gaussian falloff function,