Add render result caching.

Simply add an option to render settings to save an EXR cache,
just when the render is finished. Also changed RE_ReadRenderResult() to read
cache instead of temp sample files (those are fully volatile now anyway).

Path to save cached render results is an UserPreferences setting.

Also added 'Reload render' feature to the Image Editor (so one can now re-open a blend,
and in an Image Editor hit ctrl-R to (try to) reload last render from cache).

Reviewers: campbellbarton, sergey

Differential Revision: https://developer.blender.org/D553

3 files changed, 7 insertions, 1 deletions

diff --git a/release/scripts/startup/bl_ui/properties_render.py b/release/scripts/startup/bl_ui/properties_render.py
index ce375eca894..42cb6086c35 100644
--- a/release/scripts/startup/bl_ui/properties_render.py
+++ b/release/scripts/startup/bl_ui/properties_render.py
@@ -396,7 +396,9 @@ class RENDER_PT_output(RenderButtonsPanel, Panel):
         col.prop(rd, "use_overwrite")
         col.prop(rd, "use_placeholder")
 
-        split.prop(rd, "use_file_extension")
+        col = split.column()
+        col.prop(rd, "use_file_extension")
+        col.prop(rd, "use_render_cache")
 
         layout.template_image_settings(image_settings, color_management=False)
 
diff --git a/release/scripts/startup/bl_ui/space_image.py b/release/scripts/startup/bl_ui/space_image.py
index f19e77eff8e..97c89df0693 100644
--- a/release/scripts/startup/bl_ui/space_image.py
+++ b/release/scripts/startup/bl_ui/space_image.py
@@ -154,6 +154,8 @@ class IMAGE_MT_image(Menu):
 
         show_render = sima.show_render
 
+        layout.operator("image.read_renderlayers")
+
         if ima:
             if not show_render:
                 layout.operator("image.replace")
diff --git a/release/scripts/startup/bl_ui/space_userpref.py b/release/scripts/startup/bl_ui/space_userpref.py
index 31ca972726e..cba6f065a6f 100644
--- a/release/scripts/startup/bl_ui/space_userpref.py
+++ b/release/scripts/startup/bl_ui/space_userpref.py
@@ -865,6 +865,7 @@ class USERPREF_PT_file(Panel):
         sub.label(text="Scripts:")
         sub.label(text="Sounds:")
         sub.label(text="Temp:")
+        sub.label(text="Render Cache:")
         sub.label(text="I18n Branches:")
         sub.label(text="Image Editor:")
         sub.label(text="Animation Player:")
@@ -876,6 +877,7 @@ class USERPREF_PT_file(Panel):
         sub.prop(paths, "script_directory", text="")
         sub.prop(paths, "sound_directory", text="")
         sub.prop(paths, "temporary_directory", text="")
+        sub.prop(paths, "render_cache_directory", text="")
         sub.prop(paths, "i18n_branches_directory", text="")
         sub.prop(paths, "image_editor", text="")
         subsplit = sub.split(percentage=0.3)