Cycles: persistent images option

This option enables keeping loaded images in the memory in-between
of rendering.

Implemented by keeping render engine alive for until Render structure
is being freed.

Cycles will free all data when render finishes, optionally keeping
image manager untouched. All shaders, meshes, objects will be
re-allocated next time rendering happens.

Cycles cession and scene will be re-created from scratch if render/
scene parameters were changed.

This will also allow to keep compiled OSL shaders in memory without
need to re-compile them again.

P.S. Performance panel could be cleaned up a bit, not so much happy
     with it's vertical alignment currently but not sure how to make
     it look better.

 P.P.S. Currently the only way to free images from the device is to
       disable Persistent Images option and start rendering.

1 files changed, 51 insertions, 1 deletions

diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index 01bd5f013e3..fcc3d89f5d8 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -109,9 +109,50 @@ void BlenderSession::create_session()
 	session->reset(buffer_params, session_params.samples);
 }
 
+void BlenderSession::reset_session(BL::BlendData b_data_, BL::Scene b_scene_)
+{
+	b_data = b_data_;
+	b_scene = b_scene_;
+
+	SceneParams scene_params = BlenderSync::get_scene_params(b_scene, background);
+	SessionParams session_params = BlenderSync::get_session_params(b_engine, b_userpref, b_scene, background);
+
+	if(scene->params.modified(scene_params) ||
+	   session->params.modified(session_params))
+	{
+		/* if scene or session parameters changed, it's easier to simply re-create
+		 * them rather than trying to distinguish which settings need to be updated
+		 */
+
+		delete session;
+
+		create_session();
+
+		return;
+	}
+
+	session->progress.reset();
+	scene->reset();
+
+	/* peak memory usage should show current render peak, not peak for all renders
+	 * made by this render session
+	 */
+	session->stats.mem_peak = session->stats.mem_used;
+
+	/* sync object should be re-created */
+	sync = new BlenderSync(b_engine, b_data, b_scene, scene, !background, session->progress);
+	sync->sync_data(b_v3d, b_engine.camera_override());
+	sync->sync_camera(b_engine.camera_override(), width, height);
+
+	BufferParams buffer_params = BlenderSync::get_buffer_params(b_scene, PointerRNA_NULL, PointerRNA_NULL, scene->camera, width, height);
+	session->reset(buffer_params, session_params.samples);
+}
+
 void BlenderSession::free_session()
 {
-	delete sync;
+	if(sync)
+		delete sync;
+
 	delete session;
 }
 
@@ -304,6 +345,15 @@ void BlenderSession::render()
 	/* clear callback */
 	session->write_render_tile_cb = NULL;
 	session->update_render_tile_cb = NULL;
+
+	/* free all memory used (host and device), so we wouldn't leave render
+	 * engine with extra memory allocated
+	 */
+
+	session->device_free();
+
+	delete sync;
+	sync = NULL;
 }
 
 void BlenderSession::do_write_update_render_result(BL::RenderResult b_rr, BL::RenderLayer b_rlay, RenderTile& rtile, bool do_update_only)