v1.0.8

Author: Keith Blackstone

changelog.txt

@@ -1,3 +1,18 @@
+v1.0.8  October 1st, 2024
+fbx:
+    - fix embedded image export
+    - improved metallic workflow
+    - fix camera import orientation
+gltf:
+    - export fix - token2channel default rgb tokens to use r channel
+    - export alphablendmodetest test asset without causing missing texture error
+    - propagate one animation track through import/export
+    - anisotropy import and export
+ply:
+    - fix gsplat bounding box for framing into the asset
+utility:
+    - Write a USDRenderSettings prim in the Sdf layer & do not finalize the layer in writeLayer()
+
 v1.0.7  August 30th, 2024
 fbx:
     - improved error handling in readFbx

fbx/src/fbx.cpp

@@ -267,23 +267,60 @@ readFbx(Fbx& fbx, const std::string& filename, bool onlyMaterials)
     return true;
 }
 
+std::string
+extractFileName(const char* pFileName)
+{
+    std::string fileName(pFileName);
+    std::replace(fileName.begin(),
+                 fileName.end(),
+                 '\\',
+                 '/'); // Normalize slashes for cross-platform consistency
+    size_t lastSlash = fileName.find_last_of('/');
+    if (lastSlash != std::string::npos) {
+        fileName = fileName.substr(lastSlash + 1);
+    }
+    return fileName;
+}
+
+bool
+populateFileBufferAndSize(Fbx* fbx,
+                          const char* pFileName,
+                          const void**& pFileBuffer,
+                          size_t*& pSizeInBytes)
+{
+    for (const ImageAsset& image : fbx->images) {
+        if (image.uri == pFileName) {
+            *pFileBuffer = image.image.data();
+            *pSizeInBytes = image.image.size();
+            if (pFileBuffer && *pSizeInBytes > 0) {
+                return true;
+            }
+            break;
+        }
+    }
+    return false;
+}
+
 FbxCallback::State
 EmbedWriteCBFunction(void* pUserData,
                      FbxClassId pDataHint,
                      const char* pFileName,
                      const void** pFileBuffer,
                      size_t* pSizeInBytes)
 {
-    if (!pUserData || !pFileName || !pFileBuffer || !pSizeInBytes || *pSizeInBytes < 1) {
+    if (!pUserData || !pFileName) {
         return FbxCallback::State::eNotHandled;
     }
 
     Fbx* fbx = reinterpret_cast<Fbx*>(pUserData);
     TF_DEBUG_MSG(FILE_FORMAT_FBX, "EmbedWriteCBFunction: %s\n", pFileName);
-    for (const ImageAsset& image : fbx->images) {
-        if (image.uri == pFileName) {
-            *pFileBuffer = image.image.data();
-            *pSizeInBytes = image.image.size();
+    if (populateFileBufferAndSize(fbx, pFileName, pFileBuffer, pSizeInBytes)) {
+        return FbxCallback::State::eHandled;
+    } else {
+        // Embedded pFilename's do not have the exportParentPath or a filepath, so we need to
+        // extract the file name
+        std::string fileName = extractFileName(pFileName);
+        if (populateFileBufferAndSize(fbx, fileName.c_str(), pFileBuffer, pSizeInBytes)) {
             return FbxCallback::State::eHandled;
         }
     }

fbx/src/fbx.h

@@ -37,6 +37,16 @@ namespace adobe::usd {
 // lighting doesn't match
 constexpr float FBX_TO_USD_INTENSITY_SCALE_FACTOR = 1.0;
 
+// Camera rotation to apply to revert to FBX coordinates, on export. Inspired by the Blender code
+// base, which converts from -Z to +X with a 90º rotation around the Y axis:
+// https://github.com/blender/blender/blob/e1a44ad129d53fbd47215845be2c42fb0850135d/scripts/addons_core/io_scene_fbx/fbx_utils.py#L74C64-L74C88
+inline FbxDouble3 CAMERA_ROTATION_OFFSET_EXPORT(0.0f, 90.f, 0.f);
+
+// Light rotation to apply to revert to FBX coordinates, on export. Inspired by the Blender code
+// base, which converts from -Z to -Y with a 90º rotation around the X axis:
+// https://github.com/blender/blender/blob/e1a44ad129d53fbd47215845be2c42fb0850135d/scripts/addons_core/io_scene_fbx/fbx_utils.py#L73C63-L73C87
+inline FbxDouble3 LIGHT_ROTATION_OFFSET_EXPORT(90.f, 0.f, 0.f);
+
 struct ExportFbxOptions
 {
     bool embedImages = false;

fbx/src/fbxExport.cpp

@@ -21,6 +21,10 @@ governing permissions and limitations under the License.
 using namespace PXR_NS;
 namespace adobe::usd {
 
+// Shininess max value derived from Cosine Power
+// https://help.autodesk.com/view/MAYAUL/2025/ENU/?guid=GUID-3EDEB1B3-4E48-485A-9714-9998F6E4944D
+static constexpr float MAX_FBX_SHININESS = 100.f;
+
 struct ExportFbxContext
 {
     UsdData* usd = nullptr;
@@ -259,28 +263,25 @@ exportFbxTransform(ExportFbxContext& ctx, const Node& node, FbxNode* fbxNode)
     // Helper function calculates the transformation matrix, only to be called if needed
     auto getTransformationMatrix = [node]() {
         FbxAMatrix localTransform = GetFBXMatrixFromUSD(node.transform);
-        FbxAMatrix AdditionalRotation{};
+        FbxAMatrix additionalRotation{};
 
-        // If the node contains a camera, we need to apply the reverse Y axis rotation to orient
-        // the camera to look down the -X axis (see importFbxCamera) which is the default for fbx.
+        // Account for FBX's different coordinate system, and take the inverse on import. See
+        // comment at definition of CAMERA_ROTATION_OFFSET_EXPORT for more information
         if (node.camera >= 0) {
             TF_DEBUG_MSG(
               FILE_FORMAT_FBX,
               "exportFbxTransform: Applying 90 degree rotation around Y axis to camera node\n");
-            FbxVector4 rotation = FbxVector4(0.0f, 90.f, 0.0f);
-            AdditionalRotation.SetR(rotation);
+            additionalRotation.SetR(CAMERA_ROTATION_OFFSET_EXPORT);
         }
-        // A similar rotation was expected to be needed for exporting lights. In practice, however,
-        // a 90 degree rotation around the X axis results in the correct camera orientation. The
-        // reasons for this need to be investigated further
+        // Account for FBX's different coordinate system, and take the inverse on import. See
+        // comment at definition of LIGHT_ROTATION_OFFSET_EXPORT for more information
         if (node.light >= 0) {
             TF_DEBUG_MSG(
               FILE_FORMAT_FBX,
               "exportFbxTransform: Applying 90 degree rotation around X axis to light node\n");
-            FbxVector4 rotation = FbxVector4(90.0f, 0.f, 0.0f);
-            AdditionalRotation.SetR(rotation);
+            additionalRotation.SetR(LIGHT_ROTATION_OFFSET_EXPORT);
         }
-        return localTransform * AdditionalRotation;
+        return localTransform * additionalRotation;
     };
 
     // Translation
@@ -295,6 +296,11 @@ exportFbxTransform(ExportFbxContext& ctx, const Node& node, FbxNode* fbxNode)
 
     } else {
         // Copy the translation value from the USD node
+
+        // This code path will likely never be run, since LayerRead currently always converts to
+        // matrix transformations (with getLocalTransformation). If that is changed, this should
+        // handle alternate situations
+
         fbxNode->LclTranslation.Set(
           FbxDouble3(node.translation[0], node.translation[1], node.translation[2]));
     }
@@ -342,6 +348,33 @@ exportFbxTransform(ExportFbxContext& ctx, const Node& node, FbxNode* fbxNode)
     } else {
         // Convert the USD node's quaternion to Euler angles and use the resulting value
         FbxQuaternion fbxQuat = GetFBXQuat(node.rotation);
+
+        // This code path will likely never be run, since LayerRead currently always converts to
+        // matrix transformations (with getLocalTransformation). If that is changed, this should
+        // handle alternate situations, although the camera and light transformations have not
+        // been properly tested
+
+        if (node.camera >= 0) {
+            FbxQuaternion additionalQuat;
+
+            TF_DEBUG_MSG(
+              FILE_FORMAT_FBX,
+              "exportFbxTransform: Applying 90 degree rotation around Y axis to camera node\n");
+            FbxVector4 rotation(CAMERA_ROTATION_OFFSET_EXPORT);
+            additionalQuat.ComposeSphericalXYZ(rotation);
+            fbxQuat = fbxQuat * additionalQuat;
+        }
+        if (node.light >= 0) {
+            FbxQuaternion additionalQuat;
+
+            TF_DEBUG_MSG(
+              FILE_FORMAT_FBX,
+              "exportFbxTransform: Applying 90 degree rotation around X axis to light node\n");
+            FbxVector4 rotation(LIGHT_ROTATION_OFFSET_EXPORT);
+            additionalQuat.ComposeSphericalXYZ(rotation);
+            fbxQuat = fbxQuat * additionalQuat;
+        }
+
         FbxVector4 euler;
         euler.SetXYZ(fbxQuat);
         fbxNode->LclRotation.Set(FbxDouble3(euler[0], euler[1], euler[2]));
@@ -384,6 +417,10 @@ exportFbxTransform(ExportFbxContext& ctx, const Node& node, FbxNode* fbxNode)
     if (node.hasTransform) {
         // Extract the scale from the transformation matrix
 
+        // This code path will likely never be run, since LayerRead currently always converts to
+        // matrix transformations (with getLocalTransformation). If that is changed, this should
+        // handle alternate situations
+
         if (!transformation) {
             transformation = getTransformationMatrix();
         }
@@ -647,6 +684,8 @@ exportFbxCameras(ExportFbxContext& ctx)
         FbxCamera::EProjectionType p = c.projection == GfCamera::Projection::Perspective
                                          ? FbxCamera::EProjectionType::ePerspective
                                          : FbxCamera::EProjectionType::eOrthogonal;
+
+        fbxCamera->SetName(c.name.c_str());
         fbxCamera->ProjectionType.Set(p);
         fbxCamera->FocalLength.Set(c.f);
         fbxCamera->FieldOfView.Set(c.fov);
@@ -850,6 +889,74 @@ exportFbxInput(ExportFbxContext& ctx,
     return false;
 }
 
+// If metallic is present do the following mapping
+// 1. Disable diffuse color
+// 2. Specular color is the old diffuse color
+// 3. Set shininess which was calculated from roughness
+bool
+exportMetallicInput(ExportFbxContext& ctx,
+                    const InputTranslator& inputTranslator,
+                    const Input& input,
+                    float shininess,
+                    FbxSurfacePhong* phong)
+{
+    bool setDiffuseToZero = false;
+    if (input.image >= 0) {
+        setDiffuseToZero = true;
+    }
+    if (!setDiffuseToZero && !input.value.IsEmpty() && input.value.IsHolding<float>()) {
+        float metallic = input.value.UncheckedGet<float>();
+        if (metallic > 0.0f) {
+            setDiffuseToZero = true;
+        }
+    }
+    if (setDiffuseToZero) {
+        FbxFileTexture* diffuseTexture =
+          FbxCast<FbxFileTexture>(phong->Diffuse.GetSrcObject<FbxFileTexture>());
+        if (diffuseTexture) {
+            phong->Specular.ConnectSrcObject(diffuseTexture);
+            phong->Diffuse.DisconnectSrcObject(diffuseTexture);
+        } else {
+            FbxDouble3 oldBaseColor = phong->Diffuse.Get();
+            phong->Specular.Set(oldBaseColor);
+        }
+        phong->Diffuse.Set(FbxDouble3(0.0, 0.0, 0.0));
+        phong->DiffuseFactor.Set(0.0);
+        if (shininess > 0.0f) {
+            phong->Shininess.Set(shininess);
+        }
+    }
+
+    exportFbxInput(ctx,
+                   inputTranslator,
+                   input,
+                   phong->ReflectionFactor,
+                   FbxTexture::eStandard,
+                   AdobeTokens->raw);
+    return setDiffuseToZero;
+}
+
+// Roughness is the inverse of shininess, so we need to convert the roughness value to shininess
+// If roughness is an image texture it follows the old workflow of mapping to SpecularFactor
+// As this Phong workflow will be replaced by the Autodesk standard surface in the future.
+float
+exportRoughnessInput(ExportFbxContext& ctx,
+                     const InputTranslator& inputTranslator,
+                     const Input& input,
+                     FbxSurfacePhong* phong)
+{
+    float shininess = -1.0f;
+    if (input.image >= 0) {
+        exportFbxInput(ctx, inputTranslator, input, phong->SpecularFactor, FbxTexture::eStandard);
+    } else if (!input.value.IsEmpty() && input.value.IsHolding<float>()) {
+        float roughness = input.value.UncheckedGet<float>();
+        shininess = (1.0f - roughness) * MAX_FBX_SHININESS;
+        phong->Shininess.Set(shininess);
+        return true;
+    }
+    return shininess;
+}
+
 void
 exportFbxMaterials(ExportFbxContext& ctx)
 {
@@ -872,9 +979,9 @@ exportFbxMaterials(ExportFbxContext& ctx)
         inputTranslator.translateOpacity2Transparency(m.opacity, transparency);
         inputTranslator.translateDirect(m.normal, normal);
         inputTranslator.translateDirect(m.emissiveColor, emissiveColor);
-        // Convert Input data for occlusion, metallic and roughness to single channel textures (if
-        // necessary). This is done so that there is consistency on which channel to reference when
-        // importing.
+        // Convert Input data for occlusion, metallic and roughness to single channel textures
+        // (if necessary). This is done so that there is consistency on which channel to
+        // reference when importing.
         inputTranslator.translateToSingle("occlusion", m.occlusion, occlusion);
         inputTranslator.translateToSingle("metallic", m.metallic, metallic);
         inputTranslator.translateToSingle("roughness", m.roughness, roughness);
@@ -895,22 +1002,13 @@ exportFbxMaterials(ExportFbxContext& ctx)
           ctx, inputTranslator, occlusion, phong->AmbientFactor, FbxTexture::eStandard);
         exportFbxInput(
           ctx, inputTranslator, transparency, phong->TransparencyFactor, FbxTexture::eStandard);
-        exportFbxInput(
-          ctx, inputTranslator, metallic, phong->ReflectionFactor, FbxTexture::eStandard);
-        exportFbxInput(
-          ctx, inputTranslator, roughness, phong->SpecularFactor, FbxTexture::eStandard);
+
+        // if we have a shininess value, pass it on for the metallic workflow
+        float shininess = exportRoughnessInput(ctx, inputTranslator, roughness, phong);
+        exportMetallicInput(ctx, inputTranslator, metallic, shininess, phong);
         if (transparency.image >= 0 || !transparency.value.IsEmpty()) {
             phong->TransparentColor.Set(FbxDouble3(1));
         }
-        // phong->TransparencyFactor.Set(.5);
-        // TODO specularity is not achieved correctly. Probably roughness conversion to shininess is
-        // wrong. exportFbxInput(ctx, m.clearcoat,     phong->Reflection, FbxTexture::eStandard);
-        // exportFbxInput(ctx, m.roughness,     phong->Shininess,          FbxTexture::eStandard);
-        // exportFbxInput(ctx, m.displacement,  phong->DisplacementColor,  FbxTexture::eStandard);
-        // if (m.useSpecularWorkflow.value)
-        // exportFbxInput(ctx, m.specularColor, phong->Specular, FbxTexture::eStandard);
-        // else
-        // exportFbxInput(ctx, m.metallic, phong->Specular, FbxTexture::eStandard);
     }
     ctx.fbx->images = inputTranslator.getImages();
 }
@@ -951,7 +1049,7 @@ exportSkeletons(ExportFbxContext& ctx)
             fbxNode->LclTranslation = fbxMatrix.GetT();
             fbxNode->LclScaling = fbxMatrix.GetS();
 
-            int parent = skeleton.parents[j];
+            int parent = skeleton.jointParents[j];
             if (parent >= 0) {
                 std::string parentJoint = skeleton.joints[parent].GetString();
                 FbxNode* parentNode = skeletonNodesMap[parentJoint];
@@ -1012,7 +1110,7 @@ exportSkeletons(ExportFbxContext& ctx)
         }
 
         for (size_t j = 0; j < skeleton.animations.size(); j++) {
-            Animation& anim = ctx.usd->animations[j];
+            SkeletonAnimation& anim = ctx.usd->skeletonAnimations[j];
             if (!ctx.animStack) {
                 // TODO: Use anim.name.c_str() when implementing multi-track animation
                 ctx.animStack = FbxAnimStack::Create(ctx.fbx->scene, "AnimStack");
@@ -1039,7 +1137,8 @@ exportSkeletons(ExportFbxContext& ctx)
                 sNode->CreateCurve(sNode->GetName(), 2U)->KeyModifyBegin();
             }
 
-            // We need to convert from timeCodesPerSecond to seconds so be compute the multiplier.
+            // We need to convert from timeCodesPerSecond to seconds so be compute the
+            // multiplier.
             double secondsPerTimeCode =
               ctx.usd->timeCodesPerSecond != 0.0 ? 1.0 / ctx.usd->timeCodesPerSecond : 1.0;
             for (size_t t = 0; t < anim.times.size(); t++) {