Address Nick notes

Author: dgovil

pxr/usd/usdLightField/gaussiansAPI.h

@@ -167,16 +167,16 @@ class UsdLightFieldGaussiansAPI : public UsdAPISchemaBase
     /// Gaussians may be available in a range of shapes, therefore this list of allowedTokens is not strictly
     /// comprehensive. A renderer may support a subset or superset of the allowed tokens.
     /// 
-    /// An elipsoid is what many people will colloquially refer to as a splat.
+    /// An ellipsoid is what many people will colloquially refer to as a splat.
     /// 
     ///
     /// | ||
     /// | -- | -- |
-    /// | Declaration | `uniform token gaussianShape = "elipsoid"` |
+    /// | Declaration | `uniform token gaussianShape = "ellipsoid"` |
     /// | C++ Type | TfToken |
     /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->Token |
     /// | \ref SdfVariability "Variability" | SdfVariabilityUniform |
-    /// | \ref UsdLightFieldTokens "Allowed Values" | elipsoid, triangle, plane |
+    /// | \ref UsdLightFieldTokens "Allowed Values" | ellipsoid, triangle, plane |
     USDLIGHTFIELD_API
     UsdAttribute GetGaussianShapeAttr() const;
 
@@ -199,10 +199,10 @@ class UsdLightFieldGaussiansAPI : public UsdAPISchemaBase
     /// This attribute is a hint for the metric used to sort the gaussians with respect to the camera.
     /// 
     /// 'zDepth' sorts the gaussians using the z component of the position of the gaussians once
-    /// transformed in to camera space.
+    /// transformed in to the cameras projection space.
     /// 
     /// 'cameraDistance' sorts the gaussians using the euclidean distance between the gaussians
-    /// and the camera.
+    /// and the camera in world space.
     ///
     /// | ||
     /// | -- | -- |

pxr/usd/usdLightField/generatedSchema.usda

@@ -16,13 +16,13 @@ class "GaussiansAPI" (
     """
 )
 {
-    uniform token gaussianShape = "elipsoid" (
-        allowedTokens = ["elipsoid", "triangle", "plane"]
+    uniform token gaussianShape = "ellipsoid" (
+        allowedTokens = ["ellipsoid", "triangle", "plane"]
         doc = """The shape of the gaussian to render.
         Gaussians may be available in a range of shapes, therefore this list of allowedTokens is not strictly
         comprehensive. A renderer may support a subset or superset of the allowed tokens.
 
-        An elipsoid is what many people will colloquially refer to as a splat.
+        An ellipsoid is what many people will colloquially refer to as a splat.
         """
     )
     quath[] orientations (
@@ -63,31 +63,34 @@ class "GaussiansAPI" (
         This attribute is a hint for the metric used to sort the gaussians with respect to the camera.
 
         'zDepth' sorts the gaussians using the z component of the position of the gaussians once
-        transformed in to camera space.
+        transformed in to the cameras projection space.
 
         'cameraDistance' sorts the gaussians using the euclidean distance between the gaussians
-        and the camera."""
+        and the camera in world space."""
     )
 }
 
 class "SphericalHarmonicsAPI" (
     doc = """AppliedAPI schema to extend UsdGeomPoints to describe Spherical Harmonic data.
     Spherical harmonics data must be interpreted in context of the point types it is applied to, for example
-    with elipsoid gaussians using the GaussianAPI above.
+    with ellipsoid gaussians using the GaussianAPI above.
 
     The spherical harmonic coefficients can be provided as either half or float based data.
     If floats are present, then renderers should prefer the higher precision data if they are able.
 
-    The spherical harmonic data is provided as an array of half3 or float3 data. Each point must have the
-    same number of spherical harmonic coefficients, and therefore the array size must be equal to the number
-    of points multiplied by the number of spherical harmonic coefficients.  This allows the number of coefficients
-    present for each point can be inferred by the array size.
+    The spherical harmonic data is provided as an array of half3 or float3 data.  They are represented by 3 component values
+    as they are constructed to be the eigenfunctions of the angular part of the Laplacian in three dimensions.
+
+    Each point must have the same number of spherical harmonic coefficients, and therefore the array size must be equal
+    to the number of points multiplied by the number of spherical harmonic coefficients.
+    This allows the number of coefficients present for each point can be inferred by the array size.
 
     Spherical Harmoics contain all but the 0th degree spherical harmonic, which is already encoded in the UsdGeomPoints.displayColor attribute.
     Each point must have the same number of spherical harmonic coefficients, and therefore the array size must be
     equal to the number of points multiplied by the number of spherical harmonic coefficients (minus one due to the 0th degree being used for color).
     This allows the number of coefficients present for each point can be inferred by the array size.
 
+    Authors are responsible for authoring the correct color space metadata for their spherical harmonics data.
     """
 )
 {
@@ -99,8 +102,5 @@ class "SphericalHarmonicsAPI" (
         doc = """Float buffer containing SH data.
         See the description of the API for more information on interpreting the data."""
     )
-    uniform token sphericalHarmonicsColorSpace = "sRGB" (
-        doc = "Defines the source color space of the spherical harmonic data."
-    )
 }
 

pxr/usd/usdLightField/schema.usda

@@ -34,13 +34,13 @@ class "GaussiansAPI" (
         token[] apiSchemaCanOnlyApplyTo = ["UsdGeomPoints"]
     }
 )  {
-    uniform token gaussianShape = "elipsoid" (
-        allowedTokens = ["elipsoid", "triangle", "plane"]
+    uniform token gaussianShape = "ellipsoid" (
+        allowedTokens = ["ellipsoid", "triangle", "plane"]
         doc = """The shape of the gaussian to render.
         Gaussians may be available in a range of shapes, therefore this list of allowedTokens is not strictly
         comprehensive. A renderer may support a subset or superset of the allowed tokens.
 
-        An elipsoid is what many people will colloquially refer to as a splat.
+        An ellipsoid is what many people will colloquially refer to as a splat.
         """
     )
 
@@ -53,10 +53,10 @@ class "GaussiansAPI" (
         This attribute is a hint for the metric used to sort the gaussians with respect to the camera.
 
         'zDepth' sorts the gaussians using the z component of the position of the gaussians once
-        transformed in to camera space.
+        transformed in to the cameras projection space.
 
         'cameraDistance' sorts the gaussians using the euclidean distance between the gaussians
-        and the camera."""
+        and the camera in world space."""
     )
 
     uniform token projectionModeHint = "perspective" (
@@ -98,21 +98,24 @@ class "GaussiansAPI" (
 class "SphericalHarmonicsAPI" (
     doc = """AppliedAPI schema to extend UsdGeomPoints to describe Spherical Harmonic data.
     Spherical harmonics data must be interpreted in context of the point types it is applied to, for example
-    with elipsoid gaussians using the GaussianAPI above.
+    with ellipsoid gaussians using the GaussianAPI above.
 
     The spherical harmonic coefficients can be provided as either half or float based data.
     If floats are present, then renderers should prefer the higher precision data if they are able.
 
-    The spherical harmonic data is provided as an array of half3 or float3 data. Each point must have the
-    same number of spherical harmonic coefficients, and therefore the array size must be equal to the number
-    of points multiplied by the number of spherical harmonic coefficients.  This allows the number of coefficients
-    present for each point can be inferred by the array size.
+    The spherical harmonic data is provided as an array of half3 or float3 data.  They are represented by 3 component values
+    as they are constructed to be the eigenfunctions of the angular part of the Laplacian in three dimensions.
+
+    Each point must have the same number of spherical harmonic coefficients, and therefore the array size must be equal
+    to the number of points multiplied by the number of spherical harmonic coefficients.
+    This allows the number of coefficients present for each point can be inferred by the array size.
 
     Spherical Harmoics contain all but the 0th degree spherical harmonic, which is already encoded in the UsdGeomPoints.displayColor attribute.
     Each point must have the same number of spherical harmonic coefficients, and therefore the array size must be
     equal to the number of points multiplied by the number of spherical harmonic coefficients (minus one due to the 0th degree being used for color).
     This allows the number of coefficients present for each point can be inferred by the array size.
 
+    Authors are responsible for authoring the correct color space metadata for their spherical harmonics data.
     """
     inherits = </APISchemaBase>
 
@@ -122,10 +125,6 @@ class "SphericalHarmonicsAPI" (
     }
 )  {
 
-    uniform token sphericalHarmonicsColorSpace = "sRGB" (
-        doc = """Defines the source color space of the spherical harmonic data."""
-    )
-
     half3[] primvars:sphericalHarmonics (
         doc = """Half buffer containing spherical harmonics data.
         See the description of the API for more information on interpreting the data."""

pxr/usd/usdLightField/sphericalHarmonicsAPI.cpp

@@ -85,23 +85,6 @@ UsdLightFieldSphericalHarmonicsAPI::_GetTfType() const
     return _GetStaticTfType();
 }
 
-UsdAttribute
-UsdLightFieldSphericalHarmonicsAPI::GetSphericalHarmonicsColorSpaceAttr() const
-{
-    return GetPrim().GetAttribute(UsdLightFieldTokens->sphericalHarmonicsColorSpace);
-}
-
-UsdAttribute
-UsdLightFieldSphericalHarmonicsAPI::CreateSphericalHarmonicsColorSpaceAttr(VtValue const &defaultValue, bool writeSparsely) const
-{
-    return UsdSchemaBase::_CreateAttr(UsdLightFieldTokens->sphericalHarmonicsColorSpace,
-                       SdfValueTypeNames->Token,
-                       /* custom = */ false,
-                       SdfVariabilityUniform,
-                       defaultValue,
-                       writeSparsely);
-}
-
 UsdAttribute
 UsdLightFieldSphericalHarmonicsAPI::GetPrimvarsSphericalHarmonicsAttr() const
 {
@@ -153,7 +136,6 @@ const TfTokenVector&
 UsdLightFieldSphericalHarmonicsAPI::GetSchemaAttributeNames(bool includeInherited)
 {
     static TfTokenVector localNames = {
-        UsdLightFieldTokens->sphericalHarmonicsColorSpace,
         UsdLightFieldTokens->primvarsSphericalHarmonics,
         UsdLightFieldTokens->primvarsSphericalHarmonicsf,
     };

pxr/usd/usdLightField/sphericalHarmonicsAPI.h

@@ -37,28 +37,26 @@ class SdfAssetPath;
 ///
 /// AppliedAPI schema to extend UsdGeomPoints to describe Spherical Harmonic data.
 /// Spherical harmonics data must be interpreted in context of the point types it is applied to, for example
-/// with elipsoid gaussians using the GaussianAPI above.
+/// with ellipsoid gaussians using the GaussianAPI above.
 /// 
 /// The spherical harmonic coefficients can be provided as either half or float based data.
 /// If floats are present, then renderers should prefer the higher precision data if they are able.
 /// 
-/// The spherical harmonic data is provided as an array of half3 or float3 data. Each point must have the
-/// same number of spherical harmonic coefficients, and therefore the array size must be equal to the number
-/// of points multiplied by the number of spherical harmonic coefficients.  This allows the number of coefficients
-/// present for each point can be inferred by the array size.
+/// The spherical harmonic data is provided as an array of half3 or float3 data.  They are represented by 3 component values
+/// as they are constructed to be the eigenfunctions of the angular part of the Laplacian in three dimensions.
+/// 
+/// Each point must have the same number of spherical harmonic coefficients, and therefore the array size must be equal
+/// to the number of points multiplied by the number of spherical harmonic coefficients.
+/// This allows the number of coefficients present for each point can be inferred by the array size.
 /// 
 /// Spherical Harmoics contain all but the 0th degree spherical harmonic, which is already encoded in the UsdGeomPoints.displayColor attribute.
 /// Each point must have the same number of spherical harmonic coefficients, and therefore the array size must be
 /// equal to the number of points multiplied by the number of spherical harmonic coefficients (minus one due to the 0th degree being used for color).
 /// This allows the number of coefficients present for each point can be inferred by the array size.
 /// 
+/// Authors are responsible for authoring the correct color space metadata for their spherical harmonics data.
 /// 
 ///
-/// For any described attribute \em Fallback \em Value or \em Allowed \em Values below
-/// that are text/tokens, the actual token is published and defined in \ref UsdLightFieldTokens.
-/// So to set an attribute to the value "rightHanded", use UsdLightFieldTokens->rightHanded
-/// as the value.
-///
 class UsdLightFieldSphericalHarmonicsAPI : public UsdAPISchemaBase
 {
 public:
@@ -167,29 +165,6 @@ class UsdLightFieldSphericalHarmonicsAPI : public UsdAPISchemaBase
     USDLIGHTFIELD_API
     const TfType &_GetTfType() const override;
 
-public:
-    // --------------------------------------------------------------------- //
-    // SPHERICALHARMONICSCOLORSPACE 
-    // --------------------------------------------------------------------- //
-    /// Defines the source color space of the spherical harmonic data.
-    ///
-    /// | ||
-    /// | -- | -- |
-    /// | Declaration | `uniform token sphericalHarmonicsColorSpace = "sRGB"` |
-    /// | C++ Type | TfToken |
-    /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->Token |
-    /// | \ref SdfVariability "Variability" | SdfVariabilityUniform |
-    USDLIGHTFIELD_API
-    UsdAttribute GetSphericalHarmonicsColorSpaceAttr() const;
-
-    /// See GetSphericalHarmonicsColorSpaceAttr(), and also 
-    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create.
-    /// If specified, author \p defaultValue as the attribute's default,
-    /// sparsely (when it makes sense to do so) if \p writeSparsely is \c true -
-    /// the default for \p writeSparsely is \c false.
-    USDLIGHTFIELD_API
-    UsdAttribute CreateSphericalHarmonicsColorSpaceAttr(VtValue const &defaultValue = VtValue(), bool writeSparsely=false) const;
-
 public:
     // --------------------------------------------------------------------- //
     // PRIMVARSSPHERICALHARMONICS 

pxr/usd/usdLightField/tokens.cpp

@@ -10,7 +10,7 @@ PXR_NAMESPACE_OPEN_SCOPE
 
 UsdLightFieldTokensType::UsdLightFieldTokensType() :
     cameraDistance("cameraDistance", TfToken::Immortal),
-    elipsoid("elipsoid", TfToken::Immortal),
+    ellipsoid("ellipsoid", TfToken::Immortal),
     gaussianShape("gaussianShape", TfToken::Immortal),
     orientations("orientations", TfToken::Immortal),
     orientationsf("orientationsf", TfToken::Immortal),
@@ -22,16 +22,14 @@ UsdLightFieldTokensType::UsdLightFieldTokensType() :
     scales("scales", TfToken::Immortal),
     scalesf("scalesf", TfToken::Immortal),
     sortingModeHint("sortingModeHint", TfToken::Immortal),
-    sphericalHarmonicsColorSpace("sphericalHarmonicsColorSpace", TfToken::Immortal),
-    sRGB("sRGB", TfToken::Immortal),
     tangential("tangential", TfToken::Immortal),
     triangle("triangle", TfToken::Immortal),
     zDepth("zDepth", TfToken::Immortal),
     GaussiansAPI("GaussiansAPI", TfToken::Immortal),
     SphericalHarmonicsAPI("SphericalHarmonicsAPI", TfToken::Immortal),
     allTokens({
         cameraDistance,
-        elipsoid,
+        ellipsoid,
         gaussianShape,
         orientations,
         orientationsf,
@@ -43,8 +41,6 @@ UsdLightFieldTokensType::UsdLightFieldTokensType() :
         scales,
         scalesf,
         sortingModeHint,
-        sphericalHarmonicsColorSpace,
-        sRGB,
         tangential,
         triangle,
         zDepth,

pxr/usd/usdLightField/tokens.h

@@ -49,10 +49,10 @@ struct UsdLightFieldTokensType {
     /// 
     /// Possible value for UsdLightFieldGaussiansAPI::GetSortingModeHintAttr()
     const TfToken cameraDistance;
-    /// \brief "elipsoid"
+    /// \brief "ellipsoid"
     /// 
     /// Fallback value for UsdLightFieldGaussiansAPI::GetGaussianShapeAttr()
-    const TfToken elipsoid;
+    const TfToken ellipsoid;
     /// \brief "gaussianShape"
     /// 
     /// UsdLightFieldGaussiansAPI
@@ -97,14 +97,6 @@ struct UsdLightFieldTokensType {
     /// 
     /// UsdLightFieldGaussiansAPI
     const TfToken sortingModeHint;
-    /// \brief "sphericalHarmonicsColorSpace"
-    /// 
-    /// UsdLightFieldSphericalHarmonicsAPI
-    const TfToken sphericalHarmonicsColorSpace;
-    /// \brief "sRGB"
-    /// 
-    /// Fallback value for UsdLightFieldSphericalHarmonicsAPI::GetSphericalHarmonicsColorSpaceAttr()
-    const TfToken sRGB;
     /// \brief "tangential"
     /// 
     /// Possible value for UsdLightFieldGaussiansAPI::GetProjectionModeHintAttr()

pxr/usd/usdLightField/wrapSphericalHarmonicsAPI.cpp

@@ -33,13 +33,6 @@ namespace {
 WRAP_CUSTOM;
 
 
-static UsdAttribute
-_CreateSphericalHarmonicsColorSpaceAttr(UsdLightFieldSphericalHarmonicsAPI &self,
-                                      object defaultVal, bool writeSparsely) {
-    return self.CreateSphericalHarmonicsColorSpaceAttr(
-        UsdPythonToSdfType(defaultVal, SdfValueTypeNames->Token), writeSparsely);
-}
-        
 static UsdAttribute
 _CreatePrimvarsSphericalHarmonicsAttr(UsdLightFieldSphericalHarmonicsAPI &self,
                                       object defaultVal, bool writeSparsely) {
@@ -117,13 +110,6 @@ void wrapUsdLightFieldSphericalHarmonicsAPI()
         .def(!self)
 
 
-        .def("GetSphericalHarmonicsColorSpaceAttr",
-             &This::GetSphericalHarmonicsColorSpaceAttr)
-        .def("CreateSphericalHarmonicsColorSpaceAttr",
-             &_CreateSphericalHarmonicsColorSpaceAttr,
-             (arg("defaultValue")=object(),
-              arg("writeSparsely")=false))
-        
         .def("GetPrimvarsSphericalHarmonicsAttr",
              &This::GetPrimvarsSphericalHarmonicsAttr)
         .def("CreatePrimvarsSphericalHarmonicsAttr",

pxr/usd/usdLightField/wrapTokens.cpp

@@ -18,7 +18,7 @@ void wrapUsdLightFieldTokens()
     pxr_boost::python::class_<UsdLightFieldTokensType, pxr_boost::python::noncopyable>
         cls("Tokens", pxr_boost::python::no_init);
     _ADD_TOKEN(cls, cameraDistance);
-    _ADD_TOKEN(cls, elipsoid);
+    _ADD_TOKEN(cls, ellipsoid);
     _ADD_TOKEN(cls, gaussianShape);
     _ADD_TOKEN(cls, orientations);
     _ADD_TOKEN(cls, orientationsf);
@@ -30,8 +30,6 @@ void wrapUsdLightFieldTokens()
     _ADD_TOKEN(cls, scales);
     _ADD_TOKEN(cls, scalesf);
     _ADD_TOKEN(cls, sortingModeHint);
-    _ADD_TOKEN(cls, sphericalHarmonicsColorSpace);
-    _ADD_TOKEN(cls, sRGB);
     _ADD_TOKEN(cls, tangential);
     _ADD_TOKEN(cls, triangle);
     _ADD_TOKEN(cls, zDepth);