Refactor depsgraph/render logic to serve evaluated depsgraph to engines

User notes
----------
Compositing, rendering of multi-layers in Eevee should be fully working now.

Development notes
-----------------
Up until now we were still using the same depsgraph for rendering and viewport
evaluation. And we had to go out of our ways to be sure the depsgraphs were
updated.

Now we iterate over the (to be rendered) view layers and create a depsgraph to
each one, fully evaluated and call the render engines (Cycles, Eevee, ...) with
this viewlayer/depsgraph/evaluation context.

At this time we are not handling data persistency, Depsgraph is created from
scratch prior to rendering each frame.  So I got rid of most of the partial
update calls we had during the render pipeline.

Cycles: Brecht Van Lommel did a patch to tackle some of the required Cycles
changes but this commit mark these changes as TODOs. Basically Cycles needs to
render one layer at a time.

Reviewers: sergey, brecht

Differential Revision: https://developer.blender.org/D3073

1 files changed, 5 insertions, 3 deletions

diff --git a/source/blender/editors/object/object_bake.c b/source/blender/editors/object/object_bake.c
index a13df441c5f..e23329a7a68 100644
--- a/source/blender/editors/object/object_bake.c
+++ b/source/blender/editors/object/object_bake.c
@@ -581,6 +581,7 @@ typedef struct BakeRender {
 	Render *re;
 	Main *main;
 	Scene *scene;
+	ViewLayer *view_layer;
 	struct Object *actob;
 	int result, ready;
 
@@ -630,6 +631,7 @@ static void init_bake_internal(BakeRender *bkr, bContext *C)
 	bkr->sa = sc ? BKE_screen_find_big_area(sc, SPACE_IMAGE, 10) : NULL; /* can be NULL */
 	bkr->main = CTX_data_main(C);
 	bkr->scene = scene;
+	bkr->view_layer = view_layer;
 	bkr->actob = (scene->r.bake_flag & R_BAKE_TO_ACTIVE) ? OBACT(view_layer) : NULL;
 	bkr->re = RE_NewRender("_Bake View_");
 
@@ -735,7 +737,7 @@ static void bake_startjob(void *bkv, short *stop, short *do_update, float *progr
 	RE_test_break_cb(bkr->re, NULL, thread_break);
 	G.is_break = false;   /* BKE_blender_test_break uses this global */
 
-	RE_Database_Baking(bkr->re, bmain, scene, scene->lay, scene->r.bake_mode, bkr->actob);
+	RE_Database_Baking(bkr->re, bmain, scene, bkr->view_layer, scene->lay, scene->r.bake_mode, bkr->actob);
 
 	/* baking itself is threaded, cannot use test_break in threads. we also update optional imagewindow */
 	bkr->result = RE_bake_shade_all_selected(bkr->re, scene->r.bake_mode, bkr->actob, bkr->do_update, bkr->progress);
@@ -843,7 +845,6 @@ static int bake_image_exec(bContext *C, wmOperator *op)
 {
 	Main *bmain = CTX_data_main(C);
 	Scene *scene = CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	int result = OPERATOR_CANCELLED;
 
 	if (is_multires_bake(scene)) {
@@ -863,7 +864,8 @@ static int bake_image_exec(bContext *C, wmOperator *op)
 			RE_test_break_cb(bkr.re, NULL, thread_break);
 			G.is_break = false;   /* BKE_blender_test_break uses this global */
 
-			RE_Database_Baking(bkr.re, bmain, scene, scene->lay, scene->r.bake_mode, (scene->r.bake_flag & R_BAKE_TO_ACTIVE) ? OBACT(view_layer) : NULL);
+			RE_Database_Baking(bkr.re, bmain, scene, bkr.view_layer, scene->lay, scene->r.bake_mode,
+			                   (scene->r.bake_flag & R_BAKE_TO_ACTIVE) ? OBACT(bkr.view_layer) : NULL);
 
 			/* baking itself is threaded, cannot use test_break in threads  */
 			BLI_threadpool_init(&threads, do_bake_render, 1);