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

1 files changed, 8 insertions, 4 deletions

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);