Fix #36091: external render engines like Luxrender don't work well with the save

buffers option, it requires specific tile sizes and if they don't match what
OpenEXR expects file saving can get stuck.

Now I've made support for his optional, with a bl_use_save_buffers property for
RenderEngine, set to False by default.

4 files changed, 16 insertions, 3 deletions

diff --git a/intern/cycles/blender/addon/__init__.py b/intern/cycles/blender/addon/__init__.py
index b451b8ef3bf..cefdf504206 100644
--- a/intern/cycles/blender/addon/__init__.py
+++ b/intern/cycles/blender/addon/__init__.py
@@ -41,6 +41,7 @@ class CyclesRender(bpy.types.RenderEngine):
     bl_use_shading_nodes = True
     bl_use_preview = True
     bl_use_exclude_layers = True
+    bl_use_save_buffers = True
 
     def __init__(self):
         self.session = None
diff --git a/source/blender/makesrna/intern/rna_render.c b/source/blender/makesrna/intern/rna_render.c
index 90c0282545c..64b4e019c27 100644
--- a/source/blender/makesrna/intern/rna_render.c
+++ b/source/blender/makesrna/intern/rna_render.c
@@ -456,6 +456,10 @@ static void rna_def_render_engine(BlenderRNA *brna)
 	RNA_def_property_boolean_sdna(prop, NULL, "type->flag", RE_USE_EXCLUDE_LAYERS);
 	RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
 
+	prop = RNA_def_property(srna, "bl_use_save_buffers", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "type->flag", RE_USE_SAVE_BUFFERS);
+	RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
+
 	RNA_define_verify_sdna(1);
 }
 
diff --git a/source/blender/render/extern/include/RE_engine.h b/source/blender/render/extern/include/RE_engine.h
index 786c67f5305..d8858d9a114 100644
--- a/source/blender/render/extern/include/RE_engine.h
+++ b/source/blender/render/extern/include/RE_engine.h
@@ -57,6 +57,7 @@ struct Scene;
 #define RE_USE_POSTPROCESS		8
 #define RE_USE_SHADING_NODES	16
 #define RE_USE_EXCLUDE_LAYERS	32
+#define RE_USE_SAVE_BUFFERS		64
 
 /* RenderEngine.flag */
 #define RE_ENGINE_ANIMATION		1
diff --git a/source/blender/render/intern/source/external_engine.c b/source/blender/render/intern/source/external_engine.c
index 551f3686370..6e98d8b82ab 100644
--- a/source/blender/render/intern/source/external_engine.c
+++ b/source/blender/render/intern/source/external_engine.c
@@ -253,8 +253,14 @@ void RE_engine_end_result(RenderEngine *engine, RenderResult *result, int cancel
 		/* for exr tile render, detect tiles that are done */
 		RenderPart *pa = get_part_from_result(re, result);
 
-		if (pa)
+		if (pa) {
 			pa->status = PART_STATUS_READY;
+		}
+		else if (re->result->do_exr_tile) {
+			/* if written result does not match any tile and we are using save
+			 * buffers, we are going to get openexr save errors */
+			fprintf(stderr, "RenderEngine.end_result: dimensions do not match any OpenEXR tile.\n");
+		}
 
 		if (re->result->do_exr_tile)
 			render_result_exr_file_merge(re->result, result);
@@ -438,12 +444,13 @@ int RE_engine_render(Render *re, int do_all)
 	/* create render result */
 	BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
 	if (re->result == NULL || !(re->r.scemode & R_BUTS_PREVIEW)) {
-		int savebuffers;
+		int savebuffers = RR_USE_MEM;
 
 		if (re->result)
 			render_result_free(re->result);
 
-		savebuffers = (re->r.scemode & R_EXR_TILE_FILE) ? RR_USE_EXR : RR_USE_MEM;
+		if ((type->flag & RE_USE_SAVE_BUFFERS) && (re->r.scemode & R_EXR_TILE_FILE))
+			savebuffers = RR_USE_EXR;
 		re->result = render_result_new(re, &re->disprect, 0, savebuffers, RR_ALL_LAYERS);
 	}
 	BLI_rw_mutex_unlock(&re->resultmutex);