diff --git a/opennurbs_3dm_attributes.cpp b/opennurbs_3dm_attributes.cpp
index d48f58d8..f405bf2e 100644
--- a/opennurbs_3dm_attributes.cpp
+++ b/opennurbs_3dm_attributes.cpp
@@ -1069,6 +1069,17 @@ bool ON_3dmObjectAttributes::Read( ON_BinaryArchive& file )
 
 bool ON_3dmObjectAttributes::Internal_WriteV5( ON_BinaryArchive& file ) const
 {
+  if (m_private)
+  {
+    // Have the decal collection update the user data if anything has changed and there
+    // is actually decal data for which a user data object is needed. Note that this is
+    // not actually needed when running Rhino because the RDK decal UI directly updates
+    // the user data when changes are made. This is only needed when using ONX_Model and
+    // File3dm outside of Rhino, in case the programmer sets a decal property.
+    const unsigned int archive_3dm_version = file.Archive3dmVersion();
+    m_private->m_decals.UpdateUserData(archive_3dm_version);
+  }
+
   unsigned char c;
   // 29 Nov. 2009 S. Baer
   // Chunk version updated to 2.1 in order to support m_display_order
@@ -1403,10 +1414,6 @@ bool ON_3dmObjectAttributes::Internal_WriteV5( ON_BinaryArchive& file ) const
         rc = file.WriteBool(HatchBoundaryVisible());
         if (!rc) break;
       }
-
-      // Have the decal collection update the user data if anything has changed.
-      const unsigned int archive_3dm_version = file.Archive3dmVersion();
-      m_private->m_decals.UpdateUserData(archive_3dm_version);
     }
 
     // 15 Jun 2022 S. Baer
diff --git a/opennurbs_decals.cpp b/opennurbs_decals.cpp
index 2d80514a..3ced2c10 100644
--- a/opennurbs_decals.cpp
+++ b/opennurbs_decals.cpp
@@ -1057,16 +1057,22 @@ void ON_DecalCollection::RemoveAllDecals(void)
 
 void ON_DecalCollection::ClearDecalArray(void)
 {
-  for (int i = 0; i < m_decals.Count(); i++)
+  // 12th July 2023 John Croudy, https://mcneel.myjetbrains.com/youtrack/issue/RH-75697
+  // Only call SetChanged() if a decal is actually deleted.
+  const int count = m_decals.Count();
+  if (count > 0)
   {
-    delete m_decals[i];
+    for (int i = 0; i < count; i++)
+    {
+      delete m_decals[i];
+    }
+
+    m_decals.Destroy();
+
+    SetChanged();
   }
 
-  m_decals.Destroy();
-
   m_populated = false;
-
-  SetChanged();
 }
 
 const ON_DecalCollection& ON_DecalCollection::operator = (const ON_DecalCollection& dc)
@@ -1129,7 +1135,12 @@ void ON_DecalCollection::UpdateUserData(unsigned int archive_3dm_version) const
 {
   if (m_changed)
   {
-    SetRDKObjectInformation(*m_attr, m_root_node.String(), archive_3dm_version);
+    // 12th July 2023 John Croudy, https://mcneel.myjetbrains.com/youtrack/issue/RH-75697
+    // For there to be something useful in the XML, the root node must have at least one child node.
+    if (m_root_node.ChildCount() > 0)
+    {
+      SetRDKObjectInformation(*m_attr, m_root_node.String(), archive_3dm_version);
+    }
 
     m_changed = false;
   }
diff --git a/opennurbs_embedded_file.cpp b/opennurbs_embedded_file.cpp
index 0c41d3e3..34321343 100644
--- a/opennurbs_embedded_file.cpp
+++ b/opennurbs_embedded_file.cpp
@@ -206,7 +206,7 @@ bool ON_EmbeddedFile::LoadFromBuffer(ON_Buffer& buf)
 
   // Allocate a buffer for the data.
   auto& d = m_impl->m_data;
-  d.SetLength(buf.Size());
+  d.SetLength(size_t(buf.Size()));
 
   // Load the buffer from 'buf'.
   if (buf.Read(d.m_length, d.m_buffer.get()) != d.m_length)
@@ -251,7 +251,7 @@ bool ON_EmbeddedFile::Read(ON_BinaryArchive& archive)
   if (!archive.ReadCompressedBuffer(uncompressed_size, d.m_buffer.get(), &bFailedCRC) && !bFailedCRC)
       return false;
 
-  d.m_compressed_length = archive.CurrentPosition() - pos_before;
+  d.m_compressed_length = size_t(archive.CurrentPosition() - pos_before);
 
   return true;
 }
diff --git a/opennurbs_material.cpp b/opennurbs_material.cpp
index de48aa56..2d6ab5ff 100644
--- a/opennurbs_material.cpp
+++ b/opennurbs_material.cpp
@@ -2378,6 +2378,61 @@ ON_Texture::WRAP ON_Texture::WrapFromUnsigned( unsigned int wrap_as_unsigned )
   return ON_Texture::WRAP::repeat_wrap;
 }
 
+void ON_Texture::SetRepeat(const ON_2dVector& repeat)
+{
+  ON_3dVector offset, rotation, r;
+
+  m_uvw.DecomposeTextureMapping(offset, r, rotation);
+
+  m_uvw = ON_Xform::TextureMapping(offset, ON_3dVector(repeat.x, repeat.y, 0.0), rotation);
+}
+
+ON_2dVector ON_Texture::Repeat() const
+{
+  ON_3dVector offset, rotation, repeat;
+
+  m_uvw.DecomposeTextureMapping(offset, repeat, rotation);
+
+  return ON_2dVector(repeat.x, repeat.y);
+}
+
+void ON_Texture::SetOffset(const ON_2dVector& offset)
+{
+  ON_3dVector o, rotation, repeat;
+
+  m_uvw.DecomposeTextureMapping(o, repeat, rotation);
+
+  m_uvw = ON_Xform::TextureMapping(ON_3dVector(offset.x, offset.y, 0.0), repeat, rotation);
+}
+
+ON_2dVector ON_Texture::Offset() const
+{
+  ON_3dVector offset, rotation, repeat;
+
+  m_uvw.DecomposeTextureMapping(offset, repeat, rotation);
+
+  return ON_2dVector(offset.x, offset.y);
+}
+
+void ON_Texture::SetRotation(double rotation)
+{
+  ON_3dVector offset, r, repeat;
+
+  m_uvw.DecomposeTextureMapping(offset, repeat, r);
+
+  m_uvw = ON_Xform::TextureMapping(offset, repeat, ON_3dPoint(0.0, 0.0, rotation));
+}
+
+double ON_Texture::Rotation() const
+{
+  ON_3dVector offset, rotation, repeat;
+
+  m_uvw.DecomposeTextureMapping(offset, repeat, rotation);
+
+  return rotation.z;
+}
+
+
 bool ON_Texture::Read(
   ON_BinaryArchive& binary_archive
   )
@@ -7664,23 +7719,23 @@ const ON_Material& ON_PhysicallyBasedMaterial::Material(void) const
   return *Implementation().material;
 }
 
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::BaseColor(void) { return L"pbr-base-color"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::BRDF(void) { return L"pbr-brdf"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Subsurface(void) { return L"pbr-subsurface"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SubsurfaceScatteringColor(void) { return L"pbr-subsurface-scattering-color"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SubsurfaceScatteringRadius(void) { return L"pbr-subsurface-scattering-radius"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Specular(void) { return L"pbr-specular"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SpecularTint(void) { return L"pbr-specular-tint"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Metallic(void) { return L"pbr-metallic"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Roughness(void) { return L"pbr-roughness"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Anisotropic(void) { return L"pbr-anisotropic"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::AnisotropicRotation(void) { return L"pbr-anisotropic-rotation"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Sheen(void) { return L"pbr-sheen"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SheenTint(void) { return L"pbr-sheen-tint"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Clearcoat(void) { return L"pbr-clearcoat"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::ClearcoatRoughness(void) { return L"pbr-clearcoat-roughness"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::ClearcoatBump(void) { return L"pbr-clearcoat-bump"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::OpacityIor(void) { return L"pbr-opacity-ior"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Opacity(void) { return L"pbr-opacity"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::OpacityRoughness(void) { return L"pbr-opacity-roughness"; }
-ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Emission(void) { return L"pbr-emission"; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Anisotropic(void)                { return ON_PBR_MATERIAL_ANISOTROPIC                 ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::AnisotropicRotation(void)        { return ON_PBR_MATERIAL_ANISOTROPIC_ROTATION        ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::BaseColor(void)                  { return ON_PBR_MATERIAL_BASE_COLOR                  ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::BRDF(void)                       { return ON_PBR_MATERIAL_BRDF                        ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Clearcoat(void)                  { return ON_PBR_MATERIAL_CLEARCOAT                   ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::ClearcoatBump(void)              { return ON_PBR_MATERIAL_CLEARCOAT_BUMP              ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::ClearcoatRoughness(void)         { return ON_PBR_MATERIAL_CLEARCOAT_ROUGHNESS         ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Emission(void)                   { return ON_PBR_MATERIAL_EMISSION_COLOR              ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Metallic(void)                   { return ON_PBR_MATERIAL_METALLIC                    ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Opacity(void)                    { return ON_PBR_MATERIAL_OPACITY                     ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::OpacityIor(void)                 { return ON_PBR_MATERIAL_OPACITY_IOR                 ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::OpacityRoughness(void)           { return ON_PBR_MATERIAL_OPACITY_ROUGHNESS           ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Roughness(void)                  { return ON_PBR_MATERIAL_ROUGHNESS                   ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Sheen(void)                      { return ON_PBR_MATERIAL_SHEEN                       ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SheenTint(void)                  { return ON_PBR_MATERIAL_SHEEN_TINT                  ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Specular(void)                   { return ON_PBR_MATERIAL_SPECULAR                    ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SpecularTint(void)               { return ON_PBR_MATERIAL_SPECULAR_TINT               ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::Subsurface(void)                 { return ON_PBR_MATERIAL_SUBSURFACE                  ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SubsurfaceScatteringColor(void)  { return ON_PBR_MATERIAL_SUBSURFACE_SCATTERING_COLOR ; }
+ON_wString ON_PhysicallyBasedMaterial::ParametersNames::SubsurfaceScatteringRadius(void) { return ON_PBR_MATERIAL_SUBSURFACE_SCATTERING_RADIUS; }
diff --git a/opennurbs_public_version.h b/opennurbs_public_version.h
index 2b45578b..b686ca74 100644
--- a/opennurbs_public_version.h
+++ b/opennurbs_public_version.h
@@ -15,9 +15,9 @@
 //
 #define RMA_VERSION_YEAR   2023
 #define RMA_VERSION_MONTH  7
-#define RMA_VERSION_DATE   11
-#define RMA_VERSION_HOUR   10
-#define RMA_VERSION_MINUTE 35
+#define RMA_VERSION_DATE   13
+#define RMA_VERSION_HOUR   18
+#define RMA_VERSION_MINUTE 30
 
 ////////////////////////////////////////////////////////////////
 //
@@ -35,8 +35,8 @@
 //     3 = build system release build
 #define RMA_VERSION_BRANCH 0
 
-#define VERSION_WITH_COMMAS  8,0,23192,10350
-#define VERSION_WITH_PERIODS 8.0.23192.10350
+#define VERSION_WITH_COMMAS  8,0,23194,18300
+#define VERSION_WITH_PERIODS 8.0.23194.18300
 #define COPYRIGHT "Copyright (C) 1993-2023, Robert McNeel & Associates. All Rights Reserved."
 #define SPECIAL_BUILD_DESCRIPTION "Public OpenNURBS C++ 3dm file IO library."
 
@@ -47,8 +47,8 @@
 #define RMA_VERSION_NUMBER_SR_STRING   "SR0"
 #define RMA_VERSION_NUMBER_SR_WSTRING L"SR0"
 
-#define RMA_VERSION_WITH_PERIODS_STRING   "8.0.23192.10350"
-#define RMA_VERSION_WITH_PERIODS_WSTRING L"8.0.23192.10350"
+#define RMA_VERSION_WITH_PERIODS_STRING   "8.0.23194.18300"
+#define RMA_VERSION_WITH_PERIODS_WSTRING L"8.0.23194.18300"
 
 
 
diff --git a/opennurbs_render_content.cpp b/opennurbs_render_content.cpp
index 481654ce..732ded46 100644
--- a/opennurbs_render_content.cpp
+++ b/opennurbs_render_content.cpp
@@ -22,114 +22,6 @@
 #error ON_COMPILING_OPENNURBS must be defined when compiling opennurbs
 #endif
 
-static void ON_ConstructXform(double scale_x, double scale_y, double scale_z,
-                              double angle_x, double angle_y, double angle_z,
-                              double trans_x, double trans_y, double trans_z, ON_Xform& xform)
-{
-  // All angles in degrees.
-
-  const ON_Xform S = ON_Xform::DiagonalTransformation(scale_x, scale_y, scale_z);
-
-  ON_Xform R;
-  R.Rotation(ON_RadiansFromDegrees(angle_x), ON_3dVector::XAxis, ON_3dPoint::Origin);
-
-  auto vRotate = ON_3dVector::YAxis;
-  vRotate.Transform(R.Inverse());
-
-  ON_Xform Ry;
-  Ry.Rotation(ON_RadiansFromDegrees(angle_y), vRotate, ON_3dPoint::Origin);
-
-  R = R * Ry;
-
-  vRotate = ON_3dVector::ZAxis;
-  vRotate.Transform(R.Inverse());
-
-  ON_Xform Rz;
-  Rz.Rotation(ON_RadiansFromDegrees(angle_z), vRotate, ON_3dPoint::Origin);
-
-  R = R * Rz;
-
-  const auto T = ON_Xform::TranslationTransformation(-trans_x, -trans_y, -trans_z);
-
-  xform = S * R * T;
-}
-
-static void ON_DeconstructXform(const ON_Xform& xformIn,
-                                double& scale_x, double& scale_y, double& scale_z,
-                                double& angle_x, double& angle_y, double& angle_z,
-                                double& trans_x, double& trans_y, double& trans_z)
-{
-  // Returns all angles in degrees.
-
-  ON_Xform xform = xformIn;
-
-  scale_x = sqrt(xform[0][0] * xform[0][0] + xform[0][1] * xform[0][1] + xform[0][2] * xform[0][2]);
-  scale_y = sqrt(xform[1][0] * xform[1][0] + xform[1][1] * xform[1][1] + xform[1][2] * xform[1][2]);
-  scale_z = sqrt(xform[2][0] * xform[2][0] + xform[2][1] * xform[2][1] + xform[2][2] * xform[2][2]);
-
-  ON_Xform S;
-  ON_ConstructXform(scale_x, scale_y, scale_z, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, S);
-  S.Invert();
-
-  xform = S * xform;
-
-  const double dSinBeta = -xform[2][0];
-
-  double dCosBeta = sqrt(1.0 - dSinBeta * dSinBeta);
-  if (dCosBeta < 0.0)
-  {
-    dCosBeta = -dCosBeta;
-  }
-
-  double dSinAlpha, dCosAlpha, dSinGamma, dCosGamma;
-
-  if (dCosBeta < 1e-6)
-  {
-    dSinAlpha = -xform[1][2];
-    dCosAlpha = xform[1][1];
-    dSinGamma = 0.0;
-    dCosGamma = 1.0;
-  }
-  else
-  {
-    dSinAlpha = xform[2][1] / dCosBeta;
-    dCosAlpha = xform[2][2] / dCosBeta;
-    dSinGamma = xform[1][0] / dCosBeta;
-    dCosGamma = xform[0][0] / dCosBeta;
-  }
-
-  angle_x = (ON_DegreesFromRadians(atan2(dSinAlpha, dCosAlpha)));
-  angle_y = (ON_DegreesFromRadians(atan2(dSinBeta, dCosBeta)));
-  angle_z = (ON_DegreesFromRadians(atan2(dSinGamma, dCosGamma)));
-
-  ON_Xform R;
-  ON_ConstructXform(scale_x, scale_y, scale_z, angle_x, angle_y, angle_z, 0.0, 0.0, 0.0, R);
-  R.Invert();
-
-  ON_Xform T = R * xformIn;
-
-  trans_x = -T[0][3];
-  trans_y = -T[1][3];
-  trans_z = -T[2][3];
-}
-
-struct XF
-{
-  double scale_x = 0.0, scale_y = 0.0, scale_z = 0.0;
-  double angle_x = 0.0, angle_y = 0.0, angle_z = 0.0;
-  double trans_x = 0.0, trans_y = 0.0, trans_z = 0.0;
-};
-
-static void ON_DeconstructXform(const ON_Xform& xform, XF& xf)
-{
-  ON_DeconstructXform(xform, xf.scale_x, xf.scale_y, xf.scale_z, xf.angle_x, xf.angle_y, xf.angle_z, xf.trans_x, xf.trans_y, xf.trans_z);
-}
-
-static void ON_ConstructXform(const XF& xf, ON_Xform& xform)
-{
-  ON_ConstructXform(xf.scale_x, xf.scale_y, xf.scale_z, xf.angle_x, xf.angle_y, xf.angle_z, xf.trans_x, xf.trans_y, xf.trans_z, xform);
-}
-
 ON_OBJECT_IMPLEMENT(ON_Environment, ON_Object, "94BCA4D5-0FC7-435E-95F9-22F3927F9B2E");
 
 class ON_Environment::CImpl
@@ -1027,18 +919,68 @@ void ON_RenderContent::SetChildSlotName(const wchar_t* csn)
   _private->SetPropertyValue(ON_RENDER_CONTENT_CHILD_SLOT_NAME, csn);
 }
 
+#define MAT_POSTFIX_ON            L"on"
+#define MAT_POSTFIX_AMOUNT        L"amount"
+#define MAT_POSTFIX_DOUBLE_AMOUNT L"double-amount"
+#define MAT_POSTFIX_FILTER_ON     L"filter-on"
+
 bool ON_RenderContent::ChildSlotOn(const wchar_t* child_slot_name) const
 {
-  const auto s = ON_wString(child_slot_name) + L"-on";
+  const auto s = ON_wString(child_slot_name) + L"-" MAT_POSTFIX_ON;
   return GetParameter(s).AsBool();
 }
 
 bool ON_RenderContent::SetChildSlotOn(bool on, const wchar_t* child_slot_name)
 {
-  const auto s = ON_wString(child_slot_name) + L"-on";
+  const auto s = ON_wString(child_slot_name) + L"-" MAT_POSTFIX_ON;
   return SetParameter(s, on);
 }
 
+double ON_RenderContent::ChildSlotAmount(const wchar_t* child_slot_name, double default_value) const
+{
+  // This is complicated. See https://mcneel.myjetbrains.com/youtrack/issue/RH-58417
+
+  // Try to get the new double amount value in the range 0..1.
+  auto s = ON_wString(child_slot_name) + L"-" MAT_POSTFIX_DOUBLE_AMOUNT;
+  auto v = GetParameter(s);
+  if (!v.IsNull())
+  {
+    // Got it, so return it in the range 0..100.
+    return v.AsDouble() * 100.0;
+  }
+
+  // Couldn't get it so get the legacy amount value. This value is problematic (which is why we added
+  // the new double amount). The reason is that originally, the value was supposed to be in the range
+  // 0..100, and the Physically Based material is an example of a material that does this. But due to
+  // an oversight, the Custom Material saved this in the range 0..1. This means that here, in generic
+  // code that doesn't know which class saved the data, we have to figure out what range it's in by
+  // looking at the variant's type.
+  s = ON_wString(child_slot_name) + L"-" MAT_POSTFIX_AMOUNT;
+  v = GetParameter(s);
+  if (!v.IsNull())
+  {
+    if (v.Type() == ON_XMLVariant::Types::Integer)
+    {
+      // Got it as an integer so it's already in the range 0..100.
+      return double(v.AsInteger());
+    }
+    else
+    {
+      // The double value is in the range 0..1. Return it in the range 0..100.
+      return v.AsDouble() * 100.0;
+    }
+  }
+
+  return default_value;
+}
+
+bool ON_RenderContent::SetChildSlotAmount(double amount, const wchar_t* child_slot_name)
+{
+  const auto s = ON_wString(child_slot_name) + L"-" MAT_POSTFIX_DOUBLE_AMOUNT;
+
+  return SetParameter(s, amount / 100.0);
+}
+
 const ON_RenderContent* ON_RenderContent::FindChild(const wchar_t* child_slot_name) const
 {
   return _private->FindChild(child_slot_name);
@@ -1436,30 +1378,31 @@ ON_Texture ON_RenderTexture::ToOnTexture(void) const
 
     if (p.GetParam(ON_TEXTURE_SIMULATION_OFFSET, v))
     {
-      XF xf;
-      ON_DeconstructXform(tex.m_uvw, xf);
+      ON_3dVector offset, rotation, repeat;
+      tex.m_uvw.DecomposeTextureMapping(offset, repeat, rotation);
       const auto pt = v.As2dPoint();
-      xf.trans_x = pt[0];
-      xf.trans_y = pt[1];
-      ON_ConstructXform(xf, tex.m_uvw);
+      offset.x = pt[0];
+      offset.y = pt[1];
+      tex.m_uvw = ON_Xform::TextureMapping(offset, repeat, rotation);
     }
 
     if (p.GetParam(ON_TEXTURE_SIMULATION_REPEAT, v))
     {
-      XF xf;
-      ON_DeconstructXform(tex.m_uvw, xf);
+      ON_3dVector offset, rotation, repeat;
+      tex.m_uvw.DecomposeTextureMapping(offset, repeat, rotation);
       const auto pt = v.As2dPoint();
-      xf.scale_x = pt[0];
-      xf.scale_y = pt[1];
-      ON_ConstructXform(xf, tex.m_uvw);
+      repeat.x = pt[0];
+      repeat.y = pt[1];
+      tex.m_uvw = ON_Xform::TextureMapping(offset, repeat, rotation);
     }
 
     if (p.GetParam(ON_TEXTURE_SIMULATION_ROTATION, v))
     {
-      XF xf;
-      ON_DeconstructXform(tex.m_uvw, xf);
-      xf.angle_z = v.AsDouble();
-      ON_ConstructXform(xf, tex.m_uvw);
+      ON_3dVector offset, rotation, repeat;
+      tex.m_uvw.DecomposeTextureMapping(offset, repeat, rotation);
+      const auto pt = v.As2dPoint();
+      rotation.z = pt[0] * ON_RADIANS_TO_DEGREES;
+      tex.m_uvw = ON_Xform::TextureMapping(offset, repeat, rotation);
     }
 
     if (p.GetParam(ON_TEXTURE_SIMULATION_WRAP_TYPE, v))
@@ -1477,36 +1420,43 @@ ON_Texture ON_RenderTexture::ToOnTexture(void) const
 
     if (p.GetParam(ON_TEXTURE_SIMULATION_TRANSPARENT_COLOR, v))
     {
-        tex.m_transparent_color = v.AsColor(); // ANDY CHECK -- IS THIS RIGHT?
+      tex.m_transparent_color = v.AsColor();
     }
   }
 
+  tex.m_mode = ON_Texture::MODE::decal_texture;
+  tex.m_transparency_texture_id = ON_nil_uuid;
+
+  //tex.m_bTreatAsLinear          ??? Andy: This is on CRhRdkTexture. John: It's computed; not in the XML.
+  //tex.m_blend_constant_RGB      ???
+
+  const ON_XMLVariant v = GetParameter(L"filter");
+  tex.m_minfilter = tex.m_magfilter = v.AsBool() ? ON_Texture::FILTER::linear_filter
+                                                 : ON_Texture::FILTER::nearest_filter;
+
+  const ON_wString child_slot_name = ChildSlotName();
+
+  if (child_slot_name == ON_TEXTURE_CHILD_SLOT_NAME_BITMAP_TEXTURE)
+    tex.m_type = ON_Texture::TYPE::bitmap_texture;
+  else
+  if (child_slot_name == ON_TEXTURE_CHILD_SLOT_NAME_BUMP_TEXTURE)
+    tex.m_type = ON_Texture::TYPE::bump_texture;
+  else
+  if (child_slot_name == ON_TEXTURE_CHILD_SLOT_NAME_TRANSPARENCY_TEXTURE)
+    tex.m_type = ON_Texture::TYPE::transparency_texture;
+  else
+  if (child_slot_name == ON_TEXTURE_CHILD_SLOT_NAME_ENVIRONMENT_TEXTURE)
+  {
+    tex.m_type = ON_Texture::TYPE::emap_texture;
+    // emap_texture is OBSOLETE - set m_mapping_channel_id = ON_MappingChannel::emap_mapping
+    // tex.m_mapping_channel_id = ON_MappingChannel::emap_mapping; // ERROR!
+  }
+
   const auto* parent = Parent();
   if (nullptr != parent)
   {
-    const ON_wString csn = ChildSlotName();
-    tex.m_bOn = parent->ChildSlotOn(csn);
-
-// TODO: Discuss with Andy.
-//  tex.m_type                    ???
-//  tex.m_mode                    ???
-//  tex.m_bTreatAsLinear          ???
-//  tex.m_border_color            ???
-//  tex.m_transparency_texture_id ???
-//  tex.m_bump_scale              ???
-//  tex.m_blend_A0                ???
-//  tex.m_blend_A1                ???
-//  tex.m_blend_A2                ???
-//  tex.m_blend_A3                ???
-//  tex.m_blend_RGB0              ???
-//  tex.m_blend_RGB1              ???
-//  tex.m_blend_RGB2              ???
-//  tex.m_blend_RGB3              ???
-//  tex.m_blend_order             ???
-//  tex.m_blend_constant_A        ???
-//  tex.m_blend_constant_RGB      ???
-//  tex.m_minfilter               ???
-//  tex.m_magfilter               ???
+    tex.m_bOn = parent->ChildSlotOn(child_slot_name);
+    tex.m_blend_constant_A = parent->ChildSlotAmount(child_slot_name, 100.0) / 100.0;
   }
 
   return tex;
diff --git a/opennurbs_render_content.h b/opennurbs_render_content.h
index d1843527..f060d7ac 100644
--- a/opennurbs_render_content.h
+++ b/opennurbs_render_content.h
@@ -204,6 +204,16 @@ public:
   // Returns: True if successful, else false.
   virtual bool SetChildSlotOn(bool on, const wchar_t* child_slot_name);
 
+  // Returns the blend amount of the texture with the specified child slot name.
+  // The returned value is typically in the range 0..100 but it can be any positive or negative value.
+  // If there is no child with the specified child slot name, the method returns 'default_value'.
+  virtual double ChildSlotAmount(const wchar_t* child_slot_name, double default_value=ON_UNSET_VALUE) const;
+
+  // Sets the blend amount of the texture with the specified child slot name.
+  // Param amount is typically in the range 0..100 but it can be any positive or negative value.
+  // Returns: True if successful, else false.
+  virtual bool SetChildSlotAmount(double amount, const wchar_t* child_slot_name);
+
   // Deletes any existing child with the specified child slot name.
   // Returns: True if successful, else false.
   virtual bool DeleteChild(const wchar_t* child_slot_name);
diff --git a/opennurbs_subd.cpp b/opennurbs_subd.cpp
index df71b709..8e8bf15d 100644
--- a/opennurbs_subd.cpp
+++ b/opennurbs_subd.cpp
@@ -19877,7 +19877,6 @@ unsigned ON_SubDVertexQuadSector::SubdivisionLevel() const
 }
 
 
-
 static unsigned int Internal_MarkStuffAndMaybeMoveVertices(
   const ON_SubD& subd,
   const ON_SubDComponentPtr* cptr_list,
@@ -20168,6 +20167,8 @@ static unsigned int Internal_TransformComponents(
   );
 }
 
+
+
 unsigned int ON_SubD::TransformComponents(
   const ON_Xform& xform,
   const ON_SubDComponentPtr* cptr_list,
diff --git a/opennurbs_subd.h b/opennurbs_subd.h
index f374600e..07fdeba9 100644
--- a/opennurbs_subd.h
+++ b/opennurbs_subd.h
@@ -6655,6 +6655,7 @@ public:
     ON_SubDComponentLocation component_location
   );
 
+
   /*
   Description:
     Extrude entire subd bay adding a ring of faces around the boundary and moving the original subd.
diff --git a/opennurbs_texture.h b/opennurbs_texture.h
index aa427716..48dd8705 100644
--- a/opennurbs_texture.h
+++ b/opennurbs_texture.h
@@ -405,6 +405,16 @@ public:
   // Texture coordinate transformation.
   ON_Xform m_uvw = ON_Xform::IdentityTransformation;
 
+  // These functions are helpers for m_uvw
+  void SetRepeat(const ON_2dVector&);
+  ON_2dVector Repeat() const;
+
+  void SetOffset(const ON_2dVector&);
+  ON_2dVector Offset() const;
+
+  void SetRotation(double);
+  double Rotation() const;
+
   // If ON_UNSET_COLOR != m_border_color, then this color
   // is used when the texture coordinates are <=0 or >=1
   // and the m_wrap* value is clamp_wrap.
diff --git a/opennurbs_xform.cpp b/opennurbs_xform.cpp
index 520df9dc..e816f8d3 100644
--- a/opennurbs_xform.cpp
+++ b/opennurbs_xform.cpp
@@ -1677,6 +1677,85 @@ bool ON_Xform::DecomposeAffine(ON_Xform& L, ON_3dVector& T) const
 	return rc;
 }
 
+void ON_Xform::DecomposeTextureMapping(ON_3dVector& offset, ON_3dVector& repeat, ON_3dVector& rotation) const
+{
+  ON_Xform xform = *this;
+
+  repeat.x = sqrt(xform[0][0] * xform[0][0] + xform[0][1] * xform[0][1] + xform[0][2] * xform[0][2]);
+  repeat.y = sqrt(xform[1][0] * xform[1][0] + xform[1][1] * xform[1][1] + xform[1][2] * xform[1][2]);
+  repeat.z = sqrt(xform[2][0] * xform[2][0] + xform[2][1] * xform[2][1] + xform[2][2] * xform[2][2]);
+
+  const ON_Xform S = TextureMapping(ON_3dVector::ZeroVector, repeat, ON_3dVector::ZeroVector).Inverse();
+
+  xform = S * xform;
+
+  const double dSinBeta = -xform[2][0];
+
+  double dCosBeta = sqrt(1.0 - dSinBeta * dSinBeta);
+  if (dCosBeta < 0.0)
+  {
+    dCosBeta = -dCosBeta;
+  }
+
+  double dSinAlpha, dCosAlpha, dSinGamma, dCosGamma;
+
+  if (dCosBeta < 1e-6)
+  {
+    dSinAlpha = -xform[1][2];
+    dCosAlpha = xform[1][1];
+    dSinGamma = 0.0;
+    dCosGamma = 1.0;
+  }
+  else
+  {
+    dSinAlpha = xform[2][1] / dCosBeta;
+    dCosAlpha = xform[2][2] / dCosBeta;
+    dSinGamma = xform[1][0] / dCosBeta;
+    dCosGamma = xform[0][0] / dCosBeta;
+  }
+
+  rotation.x = atan2(dSinAlpha, dCosAlpha);
+  rotation.y = atan2(dSinBeta, dCosBeta);
+  rotation.z = atan2(dSinGamma, dCosGamma);
+
+  const ON_Xform R = TextureMapping(ON_3dVector::ZeroVector, repeat, rotation).Inverse();
+
+  const ON_Xform T = R * *this;
+
+  offset.x = -T[0][3];
+  offset.y = -T[1][3];
+  offset.z = -T[2][3];
+}
+
+//static
+const ON_Xform ON_Xform::TextureMapping(const ON_3dVector& offset, const ON_3dVector& repeat, const ON_3dVector& rotation)
+{
+  ON_Xform S = ON_Xform::DiagonalTransformation(repeat.x, repeat.y, repeat.z);
+
+  ON_Xform R;
+  R.Rotation(rotation.x, ON_3dVector::XAxis, ON_3dPoint::Origin);
+
+  ON_3dVector vRotate = ON_3dVector::YAxis;
+  vRotate.Transform(R.Inverse());
+
+  ON_Xform Ry;
+  Ry.Rotation(rotation.y, vRotate, ON_3dPoint::Origin);
+
+  R = R * Ry;
+
+  vRotate = ON_3dVector::ZAxis;
+  vRotate.Transform(R.Inverse());
+
+  ON_Xform Rz;
+  Rz.Rotation(rotation.z, vRotate, ON_3dPoint::Origin);
+
+  R = R * Rz;
+
+  const ON_Xform T = ON_Xform::TranslationTransformation(-offset.x, -offset.y, -offset.z);
+
+  return S * R * T;
+}
+
 
 bool ON_Xform::IsZero() const
 {
diff --git a/opennurbs_xform.h b/opennurbs_xform.h
index fd055cdb..8c9bddf9 100644
--- a/opennurbs_xform.h
+++ b/opennurbs_xform.h
@@ -323,6 +323,9 @@ public:
 	bool DecomposeAffine(ON_3dVector& Translation, ON_Xform& Linear) const;
 	bool DecomposeAffine(ON_Xform& Linear, ON_3dVector& Translation ) const;
 
+  // Convert an ON_Xform into the offset, repeat and rotation values used in ON_Texture and similar classes.
+  void DecomposeTextureMapping(ON_3dVector& offset, ON_3dVector& repeat, ON_3dVector& rotation) const;
+
 	// true if this is a proper rotation. 
 	bool IsRotation() const;
 
@@ -1016,6 +1019,8 @@ Notes:
     ON_PlaneEquation mirror_plane
   );
 
+  static const ON_Xform TextureMapping(const ON_3dVector& offset, const ON_3dVector& repeat, const ON_3dVector& rotation);
+
   // Description: The ChangeBasis() function is overloaded 
   //   and provides several
   //   ways to compute a change of basis transformation.
diff --git a/opennurbs_xml.cpp b/opennurbs_xml.cpp
index 5478ceb4..0860c678 100644
--- a/opennurbs_xml.cpp
+++ b/opennurbs_xml.cpp
@@ -3947,7 +3947,10 @@ void ON_XMLUserData::SetToDefaultsImpl(int) const
 
 bool ON_XMLUserData::Archive(void) const
 {
-  return true;
+  // 12th July 2023 John Croudy, https://mcneel.myjetbrains.com/youtrack/issue/RH-75697
+  // We only want to archive the user data if there's something useful in the XML. For there
+  // to be something useful in the XML, the root node must have at least one child node.
+  return _private->m_XMLRoot.ChildCount() > 0;
 }
 
 bool ON_XMLUserData::Read(ON_BinaryArchive& archive)
diff --git a/opennurbs_xml.h b/opennurbs_xml.h
index c500d325..6e71c77c 100644
--- a/opennurbs_xml.h
+++ b/opennurbs_xml.h
@@ -233,6 +233,7 @@ typedef bool (*ON_XMLRecurseChildrenCallback)(class ON_XMLNode*, void*);
 #define ON_PBR_MATERIAL_ANISOTROPIC_ROTATION           L"pbr-anisotropic-rotation"
 #define ON_PBR_MATERIAL_BASE_COLOR                     L"pbr-base-color"
 #define ON_PBR_MATERIAL_CLEARCOAT                      L"pbr-clearcoat"
+#define ON_PBR_MATERIAL_CLEARCOAT_BUMP                 L"pbr-clearcoat-bump"
 #define ON_PBR_MATERIAL_CLEARCOAT_ROUGHNESS            L"pbr-clearcoat-roughness"
 #define ON_PBR_MATERIAL_EMISSION_COLOR                 L"pbr-emission"
 #define ON_PBR_MATERIAL_METALLIC                       L"pbr-metallic"
@@ -296,6 +297,12 @@ typedef bool (*ON_XMLRecurseChildrenCallback)(class ON_XMLNode*, void*);
 #define ON_KIND_ENVIRONMENT  L"environment"
 #define ON_KIND_TEXTURE      L"texture"
 
+// Standard texture child slot names.
+#define ON_TEXTURE_CHILD_SLOT_NAME_BITMAP_TEXTURE         L"bitmap-texture"
+#define ON_TEXTURE_CHILD_SLOT_NAME_BUMP_TEXTURE           L"bump-texture"
+#define ON_TEXTURE_CHILD_SLOT_NAME_TRANSPARENCY_TEXTURE   L"transparency-texture"
+#define ON_TEXTURE_CHILD_SLOT_NAME_ENVIRONMENT_TEXTURE    L"environment-texture"
+
 #define ON_RDK_POSTFIX_SECTION  L"-section"
 
 class ON_CLASS ON_XMLVariant