Basic operator to update the Scene frame range from an Alembic cache.

4 files changed, 70 insertions, 0 deletions

diff --git a/source/blender/io/alembic/ABC_alembic.h b/source/blender/io/alembic/ABC_alembic.h
index ca503c35d80..83628704110 100644
--- a/source/blender/io/alembic/ABC_alembic.h
+++ b/source/blender/io/alembic/ABC_alembic.h
@@ -104,6 +104,8 @@ AbcArchiveHandle *ABC_create_handle(struct Main *bmain,
                                     const char *filename,
                                     struct ListBase *object_paths);
 
+bool ABC_get_min_max_time(AbcArchiveHandle *handle, double *r_min_time, double *r_max_time);
+
 void ABC_free_handle(AbcArchiveHandle *handle);
 
 void ABC_get_transform(struct CacheReader *reader,
diff --git a/source/blender/io/alembic/intern/abc_reader_archive.cc b/source/blender/io/alembic/intern/abc_reader_archive.cc
index 4951dc0e035..c232665d5b7 100644
--- a/source/blender/io/alembic/intern/abc_reader_archive.cc
+++ b/source/blender/io/alembic/intern/abc_reader_archive.cc
@@ -38,6 +38,9 @@ using Alembic::Abc::ErrorHandler;
 using Alembic::Abc::Exception;
 using Alembic::Abc::IArchive;
 using Alembic::Abc::kWrapExisting;
+using Alembic::Abc::TimeSamplingPtr;
+using Alembic::Abc::TimeSamplingType;
+using Alembic::Abc::chrono_t;
 
 namespace blender::io::alembic {
 
@@ -106,4 +109,37 @@ Alembic::Abc::IObject ArchiveReader::getTop()
   return m_archive.getTop();
 }
 
+TimeInfo ArchiveReader::getTimeInfo()
+{
+  const uint32_t num_time_sampling_ptrs = m_archive.getNumTimeSamplings();
+
+  chrono_t min_time =  std::numeric_limits<chrono_t>::max();
+  chrono_t max_time = -std::numeric_limits<chrono_t>::max();
+
+  for (uint32_t i = 0; i < num_time_sampling_ptrs; ++i) {
+    const Alembic::Abc::index_t max_samples = m_archive.getMaxNumSamplesForTimeSamplingIndex(i);
+
+    /* This can only happen in very old files, predating the original Blender Alembic support,
+     * however let's make sure this case is handled. */
+    if (max_samples == INDEX_UNKNOWN) {
+      continue;
+    }
+
+    const TimeSamplingPtr time_sampling_ptr = m_archive.getTimeSampling(i);
+    assert(time_sampling_ptr);
+
+    const TimeSamplingType &time_sampling_type = time_sampling_ptr->getTimeSamplingType();
+
+    /* Avoid the default time sampling, it should be at index 0, but we never know. */
+    if (time_sampling_ptr->getNumStoredTimes() == 1 && time_sampling_ptr->getStoredTimes()[0] == 0.0 && time_sampling_type.getTimePerCycle() == 1.0) {
+      continue;
+    }
+
+    min_time = std::min(min_time, time_sampling_ptr->getSampleTime(0));
+    max_time = std::max(max_time, time_sampling_ptr->getSampleTime(max_samples - 1));
+  }
+
+  return {min_time, max_time};
+}
+
 }  // namespace blender::io::alembic
diff --git a/source/blender/io/alembic/intern/abc_reader_archive.h b/source/blender/io/alembic/intern/abc_reader_archive.h
index 67000194aa1..56177187775 100644
--- a/source/blender/io/alembic/intern/abc_reader_archive.h
+++ b/source/blender/io/alembic/intern/abc_reader_archive.h
@@ -31,6 +31,11 @@ struct Main;
 
 namespace blender::io::alembic {
 
+struct TimeInfo {
+   Alembic::Abc::chrono_t min_time;
+   Alembic::Abc::chrono_t max_time;
+};
+
 /* Wrappers around input and output archives. The goal is to be able to use
  * streams so that unicode paths work on Windows (T49112), and to make sure that
  * the stream objects remain valid as long as the archives are open.
@@ -47,6 +52,8 @@ class ArchiveReader {
   bool valid() const;
 
   Alembic::Abc::IObject getTop();
+
+  TimeInfo getTimeInfo();
 };
 
 }  // namespace blender::io::alembic
diff --git a/source/blender/io/alembic/intern/alembic_capi.cc b/source/blender/io/alembic/intern/alembic_capi.cc
index edef76ad98d..7e40c70dc6b 100644
--- a/source/blender/io/alembic/intern/alembic_capi.cc
+++ b/source/blender/io/alembic/intern/alembic_capi.cc
@@ -178,6 +178,31 @@ AbcArchiveHandle *ABC_create_handle(struct Main *bmain,
   return handle_from_archive(archive);
 }
 
+bool ABC_get_min_max_time(AbcArchiveHandle *handle, double *r_min_time, double *r_max_time)
+{
+  ArchiveReader *archive = archive_from_handle(handle);
+
+  if (!archive) {
+    return false;
+  }
+
+  if (!archive->valid()) {
+    return false;
+  }
+
+  const TimeInfo time_info = archive->getTimeInfo();
+
+  if (r_min_time) {
+    *r_min_time = time_info.min_time;
+  }
+
+  if (r_max_time) {
+    *r_max_time = time_info.max_time;
+  }
+
+  return true;
+}
+
 void ABC_free_handle(AbcArchiveHandle *handle)
 {
   delete archive_from_handle(handle);