animation framerate option

README.md

@@ -55,6 +55,8 @@ Usage:
                                 (never|auto|always).
       --compute-normals arg     When to compute normals for vertices
                                 (never|broken|missing|always).
+      --anim-framerate arg      Select baked animation framerate
+                                (bake24|bake30|bake60).
   -k, --keep-attribute arg      Used repeatedly to build a limiting set of
                                 vertex attributes to keep.
   -v, --verbose                 Enable verbose output.

src/FBX2glTF.cpp

@@ -103,6 +103,26 @@ int main(int argc, char* argv[]) {
          "When to compute vertex normals from mesh geometry.")
       ->type_name("(never|broken|missing|always)");
 
+  app.add_option(
+         "--anim-framerate",
+         [&](std::vector<std::string> choices) -> bool {
+           for (const std::string choice : choices) {
+             if (choice == "bake24") {
+               gltfOptions.animationFramerate = AnimationFramerateOptions::BAKE24;
+             } else if (choice == "bake30") {
+               gltfOptions.animationFramerate = AnimationFramerateOptions::BAKE30;
+             } else if (choice == "bake60") {
+               gltfOptions.animationFramerate = AnimationFramerateOptions::BAKE60;
+             } else {
+               fmt::printf("Unknown --anim-framerate: %s\n", choice);
+               throw CLI::RuntimeError(1);
+             }
+           }
+           return true;
+         },
+         "Select baked animation framerate.")
+      ->type_name("(bake24|bake30|bake60)");
+
   const auto opt_flip_u = app.add_flag("--flip-u", "Flip all U texture coordinates.");
   const auto opt_no_flip_u = app.add_flag("--no-flip-u", "Don't flip U texture coordinates.");
   const auto opt_flip_v = app.add_flag("--flip-v", "Flip all V texture coordinates.");
@@ -302,7 +322,7 @@ int main(int argc, char* argv[]) {
   if (verboseOutput) {
     fmt::printf("Loading FBX File: %s\n", inputPath);
   }
-  if (!LoadFBXFile(raw, inputPath.c_str(), "png;jpg;jpeg")) {
+  if (!LoadFBXFile(raw, inputPath.c_str(), "png;jpg;jpeg", gltfOptions)) {
     fmt::fprintf(stderr, "ERROR:: Failed to parse FBX: %s\n", inputPath);
     return 1;
   }

src/FBX2glTF.h

@@ -56,6 +56,12 @@ enum class UseLongIndicesOptions {
     ALWAYS,     // only ever use 32-bit indices
 };
 
+enum class AnimationFramerateOptions {
+    BAKE24,     // bake animations at 24 fps
+    BAKE30,     // bake animations at 30 fps
+    BAKE60,     // bake animations at 60 fps
+};
+
 /**
 * User-supplied options that dictate the nature of the glTF being generated.
 */
@@ -103,4 +109,6 @@ struct GltfOptions
     ComputeNormalsOption computeNormals = ComputeNormalsOption::BROKEN;
     /** When to use 32-bit indices. */
     UseLongIndicesOptions useLongIndices = UseLongIndicesOptions::AUTO;
+    /** Select baked animation framerate. */
+    AnimationFramerateOptions animationFramerate = AnimationFramerateOptions::BAKE24;
 };

src/fbx/Fbx2Raw.cpp

@@ -721,8 +721,19 @@ static void ReadNodeHierarchy(
   }
 }
 
-static void ReadAnimations(RawModel& raw, FbxScene* pScene) {
+static void ReadAnimations(RawModel& raw, FbxScene* pScene, const GltfOptions& options) {
   FbxTime::EMode eMode = FbxTime::eFrames24;
+  switch (options.animationFramerate) {
+    case AnimationFramerateOptions::BAKE24:
+      eMode = FbxTime::eFrames24;
+      break;
+    case AnimationFramerateOptions::BAKE30:
+      eMode = FbxTime::eFrames30;
+      break;
+    case AnimationFramerateOptions::BAKE60:
+      eMode = FbxTime::eFrames60;
+      break;
+  }
   const double epsilon = 1e-5f;
 
   const int animationCount = pScene->GetSrcObjectCount<FbxAnimStack>();
@@ -996,7 +1007,11 @@ static void FindFbxTextures(
   }
 }
 
-bool LoadFBXFile(RawModel& raw, const char* fbxFileName, const char* textureExtensions) {
+bool LoadFBXFile(
+    RawModel& raw,
+    const char* fbxFileName,
+    const char* textureExtensions,
+    const GltfOptions& options) {
   FbxManager* pManager = FbxManager::Create();
   FbxIOSettings* pIoSettings = FbxIOSettings::Create(pManager, IOSROOT);
   pManager->SetIOSettings(pIoSettings);
@@ -1042,7 +1057,7 @@ bool LoadFBXFile(RawModel& raw, const char* fbxFileName, const char* textureExte
 
   ReadNodeHierarchy(raw, pScene, pScene->GetRootNode(), 0, "");
   ReadNodeAttributes(raw, pScene, pScene->GetRootNode(), textureLocations);
-  ReadAnimations(raw, pScene);
+  ReadAnimations(raw, pScene, options);
 
   pScene->Destroy();
   pManager->Destroy();

src/fbx/Fbx2Raw.hpp

@@ -11,6 +11,6 @@
 
 #include "raw/RawModel.hpp"
 
-bool LoadFBXFile(RawModel& raw, const char* fbxFileName, const char* textureExtensions);
+bool LoadFBXFile(RawModel& raw, const char* fbxFileName, const char* textureExtensions, const GltfOptions& options);
 
 json TranscribeProperty(FbxProperty& prop);