Bake-API: reduce memory footprint when baking more than one object (Fix T41092)

Combine all the highpoly pixel arrays into a single array with a lookup
object_id for each of the highpoly objects.

Note: This changes the Bake API, external engines should refer to the
bake_api.c for the latest API.

Many thanks for Sergey Sharybin for the complete review, changes
suggestion and feedback. (you rock!)

Reviewers: sergey

Subscribers: pildanovak, marcclintdion, monio, metalliandy, brecht

Maniphest Tasks: T41092

Differential Revision: https://developer.blender.org/D772

7 files changed, 22 insertions, 12 deletions

diff --git a/intern/cycles/blender/addon/__init__.py b/intern/cycles/blender/addon/__init__.py
index 5b0c6a84bb5..9c78e0c9a62 100644
--- a/intern/cycles/blender/addon/__init__.py
+++ b/intern/cycles/blender/addon/__init__.py
@@ -65,8 +65,8 @@ class CyclesRender(bpy.types.RenderEngine):
     def render(self, scene):
         engine.render(self)
 
-    def bake(self, scene, obj, pass_type, pixel_array, num_pixels, depth, result):
-        engine.bake(self, obj, pass_type, pixel_array, num_pixels, depth, result)
+    def bake(self, scene, obj, pass_type, object_id, pixel_array, num_pixels, depth, result):
+        engine.bake(self, obj, pass_type, object_id, pixel_array, num_pixels, depth, result)
 
     # viewport render
     def view_update(self, context):
diff --git a/intern/cycles/blender/addon/engine.py b/intern/cycles/blender/addon/engine.py
index e50a8e45b52..4187e2381ac 100644
--- a/intern/cycles/blender/addon/engine.py
+++ b/intern/cycles/blender/addon/engine.py
@@ -59,11 +59,11 @@ def render(engine):
         _cycles.render(engine.session)
 
 
-def bake(engine, obj, pass_type, pixel_array, num_pixels, depth, result):
+def bake(engine, obj, pass_type, object_id, pixel_array, num_pixels, depth, result):
     import _cycles
     session = getattr(engine, "session", None)
     if session is not None:
-        _cycles.bake(engine.session, obj.as_pointer(), pass_type, pixel_array.as_pointer(), num_pixels, depth, result.as_pointer())
+        _cycles.bake(engine.session, obj.as_pointer(), pass_type, object_id, pixel_array.as_pointer(), num_pixels, depth, result.as_pointer())
 
 
 def reset(engine, data, scene):
diff --git a/intern/cycles/blender/blender_python.cpp b/intern/cycles/blender/blender_python.cpp
index b9521090c93..200003fbf70 100644
--- a/intern/cycles/blender/blender_python.cpp
+++ b/intern/cycles/blender/blender_python.cpp
@@ -189,9 +189,9 @@ static PyObject *bake_func(PyObject * /*self*/, PyObject *args)
 	PyObject *pysession, *pyobject;
 	PyObject *pypixel_array, *pyresult;
 	const char *pass_type;
-	int num_pixels, depth;
+	int num_pixels, depth, object_id;
 
-	if(!PyArg_ParseTuple(args, "OOsOiiO", &pysession, &pyobject, &pass_type, &pypixel_array,  &num_pixels, &depth, &pyresult))
+	if(!PyArg_ParseTuple(args, "OOsiOiiO", &pysession, &pyobject, &pass_type, &object_id, &pypixel_array, &num_pixels, &depth, &pyresult))
 		return NULL;
 
 	BlenderSession *session = (BlenderSession*)PyLong_AsVoidPtr(pysession);
@@ -208,7 +208,7 @@ static PyObject *bake_func(PyObject * /*self*/, PyObject *args)
 
 	python_thread_state_save(&session->python_thread_state);
 
-	session->bake(b_object, pass_type, b_bake_pixel, (size_t)num_pixels, depth, (float *)b_result);
+	session->bake(b_object, pass_type, object_id, b_bake_pixel, (size_t)num_pixels, depth, (float *)b_result);
 
 	python_thread_state_restore(&session->python_thread_state);
 
diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index bdacea0cd7e..897514668f6 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -511,18 +511,22 @@ void BlenderSession::render()
 	sync = NULL;
 }
 
-static void populate_bake_data(BakeData *data, BL::BakePixel pixel_array, const int num_pixels)
+static void populate_bake_data(BakeData *data, const int object_id, BL::BakePixel pixel_array, const int num_pixels)
 {
 	BL::BakePixel bp = pixel_array;
 
 	int i;
 	for(i=0; i < num_pixels; i++) {
-		data->set(i, bp.primitive_id(), bp.uv(), bp.du_dx(), bp.du_dy(), bp.dv_dx(), bp.dv_dy());
+		if(bp.object_id() == object_id) {
+			data->set(i, bp.primitive_id(), bp.uv(), bp.du_dx(), bp.du_dy(), bp.dv_dx(), bp.dv_dy());
+		} else {
+			data->set_null(i);
+		}
 		bp = bp.next();
 	}
 }
 
-void BlenderSession::bake(BL::Object b_object, const string& pass_type, BL::BakePixel pixel_array, const size_t num_pixels, const int /*depth*/, float result[])
+void BlenderSession::bake(BL::Object b_object, const string& pass_type, const int object_id, BL::BakePixel pixel_array, const size_t num_pixels, const int /*depth*/, float result[])
 {
 	ShaderEvalType shader_type = get_shader_type(pass_type);
 	size_t object_index = OBJECT_NONE;
@@ -578,7 +582,7 @@ void BlenderSession::bake(BL::Object b_object, const string& pass_type, BL::Bake
 
 	BakeData *bake_data = scene->bake_manager->init(object, tri_offset, num_pixels);
 
-	populate_bake_data(bake_data, pixel_array, num_pixels);
+	populate_bake_data(bake_data, object_id, pixel_array, num_pixels);
 
 	/* set number of samples */
 	session->tile_manager.set_samples(session_params.samples);
diff --git a/intern/cycles/blender/blender_session.h b/intern/cycles/blender/blender_session.h
index b6fc709b92e..708776dc8ca 100644
--- a/intern/cycles/blender/blender_session.h
+++ b/intern/cycles/blender/blender_session.h
@@ -52,7 +52,7 @@ public:
 	/* offline render */
 	void render();
 
-	void bake(BL::Object b_object, const string& pass_type, BL::BakePixel pixel_array, const size_t num_pixels, const int depth, float pixels[]);
+	void bake(BL::Object b_object, const string& pass_type, const int object_id, BL::BakePixel pixel_array, const size_t num_pixels, const int depth, float pixels[]);
 
 	void write_render_result(BL::RenderResult b_rr, BL::RenderLayer b_rlay, RenderTile& rtile);
 	void write_render_tile(RenderTile& rtile);
diff --git a/intern/cycles/render/bake.cpp b/intern/cycles/render/bake.cpp
index c5201366bb2..4bbac0f91d1 100644
--- a/intern/cycles/render/bake.cpp
+++ b/intern/cycles/render/bake.cpp
@@ -55,6 +55,11 @@ void BakeData::set(int i, int prim, float uv[2], float dudx, float dudy, float d
 	m_dvdy[i] = dvdy;
 }
 
+void BakeData::set_null(int i)
+{
+	m_primitive[i] = -1;
+}
+
 int BakeData::object()
 {
 	return m_object;
diff --git a/intern/cycles/render/bake.h b/intern/cycles/render/bake.h
index 9ff10dafa0e..14d975a4b4e 100644
--- a/intern/cycles/render/bake.h
+++ b/intern/cycles/render/bake.h
@@ -31,6 +31,7 @@ public:
 	~BakeData();
 
 	void set(int i, int prim, float uv[2], float dudx, float dudy, float dvdx, float dvdy);
+	void set_null(int i);
 	int object();
 	size_t size();
 	uint4 data(int i);