1 files changed, 233 insertions, 0 deletions
diff --git a/source/blender/io/usd/intern/usd_capi.cc b/source/blender/io/usd/intern/usd_capi.cc
new file mode 100644
index 00000000000..83e11cd7bf3
--- /dev/null
+++ b/source/blender/io/usd/intern/usd_capi.cc
@@ -0,0 +1,233 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2019 Blender Foundation.
+ * All rights reserved.
+ */
+
+#include "usd.h"
+#include "usd_hierarchy_iterator.h"
+
+#include <pxr/pxr.h>
+#include <pxr/usd/usd/stage.h>
+#include <pxr/usd/usdGeom/tokens.h>
+
+#include "MEM_guardedalloc.h"
+
+extern "C" {
+#include "DEG_depsgraph.h"
+#include "DEG_depsgraph_build.h"
+#include "DEG_depsgraph_query.h"
+
+#include "DNA_scene_types.h"
+
+#include "BKE_blender_version.h"
+#include "BKE_context.h"
+#include "BKE_global.h"
+#include "BKE_scene.h"
+
+#include "BLI_fileops.h"
+#include "BLI_path_util.h"
+#include "BLI_string.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+}
+
+namespace USD {
+
+struct ExportJobData {
+  ViewLayer *view_layer;
+  Main *bmain;
+  Depsgraph *depsgraph;
+  wmWindowManager *wm;
+
+  char filename[FILE_MAX];
+  USDExportParams params;
+
+  short *stop;
+  short *do_update;
+  float *progress;
+
+  bool was_canceled;
+  bool export_ok;
+};
+
+static void export_startjob(void *customdata, short *stop, short *do_update, float *progress)
+{
+  ExportJobData *data = static_cast<ExportJobData *>(customdata);
+
+  data->stop = stop;
+  data->do_update = do_update;
+  data->progress = progress;
+  data->was_canceled = false;
+
+  G.is_rendering = true;
+  WM_set_locked_interface(data->wm, true);
+  G.is_break = false;
+
+  // Construct the depsgraph for exporting.
+  Scene *scene = DEG_get_input_scene(data->depsgraph);
+  ViewLayer *view_layer = DEG_get_input_view_layer(data->depsgraph);
+  DEG_graph_build_from_view_layer(data->depsgraph, data->bmain, scene, view_layer);
+  BKE_scene_graph_update_tagged(data->depsgraph, data->bmain);
+
+  *progress = 0.0f;
+  *do_update = true;
+
+  // For restoring the current frame after exporting animation is done.
+  const int orig_frame = CFRA;
+
+  pxr::UsdStageRefPtr usd_stage = pxr::UsdStage::CreateNew(data->filename);
+  if (!usd_stage) {
+    /* This happens when the USD JSON files cannot be found. When that happens,
+     * the USD library doesn't know it has the functionality to write USDA and
+     * USDC files, and creating a new UsdStage fails. */
+    WM_reportf(
+        RPT_ERROR, "USD Export: unable to find suitable USD plugin to write %s", data->filename);
+    data->export_ok = false;
+    return;
+  }
+
+  usd_stage->SetMetadata(pxr::UsdGeomTokens->upAxis, pxr::VtValue(pxr::UsdGeomTokens->z));
+  usd_stage->SetMetadata(pxr::UsdGeomTokens->metersPerUnit,
+                         pxr::VtValue(scene->unit.scale_length));
+  usd_stage->GetRootLayer()->SetDocumentation(std::string("Blender ") + versionstr);
+
+  // Set up the stage for animated data.
+  if (data->params.export_animation) {
+    usd_stage->SetTimeCodesPerSecond(FPS);
+    usd_stage->SetStartTimeCode(scene->r.sfra);
+    usd_stage->SetEndTimeCode(scene->r.efra);
+  }
+
+  USDHierarchyIterator iter(data->depsgraph, usd_stage, data->params);
+
+  if (data->params.export_animation) {
+    // Writing the animated frames is not 100% of the work, but it's our best guess.
+    float progress_per_frame = 1.0f / std::max(1, (scene->r.efra - scene->r.sfra + 1));
+
+    for (float frame = scene->r.sfra; frame <= scene->r.efra; frame++) {
+      if (G.is_break || (stop != nullptr && *stop)) {
+        break;
+      }
+
+      // Update the scene for the next frame to render.
+      scene->r.cfra = static_cast<int>(frame);
+      scene->r.subframe = frame - scene->r.cfra;
+      BKE_scene_graph_update_for_newframe(data->depsgraph, data->bmain);
+
+      iter.set_export_frame(frame);
+      iter.iterate_and_write();
+
+      *progress += progress_per_frame;
+      *do_update = true;
+    }
+  }
+  else {
+    // If we're not animating, a single iteration over all objects is enough.
+    iter.iterate_and_write();
+  }
+
+  iter.release_writers();
+  usd_stage->GetRootLayer()->Save();
+
+  // Finish up by going back to the keyframe that was current before we started.
+  if (CFRA != orig_frame) {
+    CFRA = orig_frame;
+    BKE_scene_graph_update_for_newframe(data->depsgraph, data->bmain);
+  }
+
+  data->export_ok = !data->was_canceled;
+
+  *progress = 1.0f;
+  *do_update = true;
+}
+
+static void export_endjob(void *customdata)
+{
+  ExportJobData *data = static_cast<ExportJobData *>(customdata);
+
+  DEG_graph_free(data->depsgraph);
+
+  if (data->was_canceled && BLI_exists(data->filename)) {
+    BLI_delete(data->filename, false, false);
+  }
+
+  G.is_rendering = false;
+  WM_set_locked_interface(data->wm, false);
+}
+
+}  // namespace USD
+
+bool USD_export(bContext *C,
+                const char *filepath,
+                const USDExportParams *params,
+                bool as_background_job)
+{
+  ViewLayer *view_layer = CTX_data_view_layer(C);
+  Scene *scene = CTX_data_scene(C);
+
+  USD::ExportJobData *job = static_cast<USD::ExportJobData *>(
+      MEM_mallocN(sizeof(USD::ExportJobData), "ExportJobData"));
+
+  job->bmain = CTX_data_main(C);
+  job->wm = CTX_wm_manager(C);
+  job->export_ok = false;
+  BLI_strncpy(job->filename, filepath, sizeof(job->filename));
+
+  job->depsgraph = DEG_graph_new(job->bmain, scene, view_layer, params->evaluation_mode);
+  job->params = *params;
+
+  bool export_ok = false;
+  if (as_background_job) {
+    wmJob *wm_job = WM_jobs_get(
+        job->wm, CTX_wm_window(C), scene, "USD Export", WM_JOB_PROGRESS, WM_JOB_TYPE_ALEMBIC);
+
+    /* setup job */
+    WM_jobs_customdata_set(wm_job, job, MEM_freeN);
+    WM_jobs_timer(wm_job, 0.1, NC_SCENE | ND_FRAME, NC_SCENE | ND_FRAME);
+    WM_jobs_callbacks(wm_job, USD::export_startjob, NULL, NULL, USD::export_endjob);
+
+    WM_jobs_start(CTX_wm_manager(C), wm_job);
+  }
+  else {
+    /* Fake a job context, so that we don't need NULL pointer checks while exporting. */
+    short stop = 0, do_update = 0;
+    float progress = 0.f;
+
+    USD::export_startjob(job, &stop, &do_update, &progress);
+    USD::export_endjob(job);
+    export_ok = job->export_ok;
+
+    MEM_freeN(job);
+  }
+
+  return export_ok;
+}
+
+int USD_get_version(void)
+{
+  /* USD 19.11 defines:
+   *
+   * #define PXR_MAJOR_VERSION 0
+   * #define PXR_MINOR_VERSION 19
+   * #define PXR_PATCH_VERSION 11
+   * #define PXR_VERSION 1911
+   *
+   * So the major version is implicit/invisible in the public version number.
+   */
+  return PXR_VERSION;
+}