Cycles: persistent images option

This option enables keeping loaded images in the memory in-between
of rendering.

Implemented by keeping render engine alive for until Render structure
is being freed.

Cycles will free all data when render finishes, optionally keeping
image manager untouched. All shaders, meshes, objects will be
re-allocated next time rendering happens.

Cycles cession and scene will be re-created from scratch if render/
scene parameters were changed.

This will also allow to keep compiled OSL shaders in memory without
need to re-compile them again.

P.S. Performance panel could be cleaned up a bit, not so much happy
     with it's vertical alignment currently but not sure how to make
     it look better.

 P.P.S. Currently the only way to free images from the device is to
       disable Persistent Images option and start rendering.

4 files changed, 22 insertions, 1 deletions

diff --git a/intern/cycles/blender/addon/__init__.py b/intern/cycles/blender/addon/__init__.py
index 16697c08b2b..0fad2ac5618 100644
--- a/intern/cycles/blender/addon/__init__.py
+++ b/intern/cycles/blender/addon/__init__.py
@@ -48,7 +48,11 @@ class CyclesRender(bpy.types.RenderEngine):
 
     # final render
     def update(self, data, scene):
-        engine.create(self, data, scene)
+        if not self.session:
+            engine.create(self, data, scene)
+        else:
+            engine.reset(self, data, scene)
+
         engine.update(self, data, scene)
 
     def render(self, scene):
diff --git a/intern/cycles/blender/addon/engine.py b/intern/cycles/blender/addon/engine.py
index e4f80cb4d5d..ca5cbee9325 100644
--- a/intern/cycles/blender/addon/engine.py
+++ b/intern/cycles/blender/addon/engine.py
@@ -61,6 +61,13 @@ def render(engine):
         _cycles.render(engine.session)
 
 
+def reset(engine, data, scene):
+    import _cycles
+    data = data.as_pointer()
+    scene = scene.as_pointer()
+    _cycles.reset(engine.session, data, scene)
+
+
 def update(engine, data, scene):
     import _cycles
     _cycles.sync(engine.session)
diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index 0b8ca6e0fbe..32b07f47ba8 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -297,6 +297,12 @@ class CyclesRenderSettings(bpy.types.PropertyGroup):
                 default=False,
                 )
 
+        cls.use_persistent_images = BoolProperty(
+                name="Persistent Images",
+                description="Keep images loaded on the device so they could be reused by next render",
+                default=False,
+                )
+
     @classmethod
     def unregister(cls):
         del bpy.types.Scene.cycles
diff --git a/intern/cycles/blender/addon/ui.py b/intern/cycles/blender/addon/ui.py
index 9cc58e65bef..d8d8c11baa6 100644
--- a/intern/cycles/blender/addon/ui.py
+++ b/intern/cycles/blender/addon/ui.py
@@ -216,6 +216,10 @@ class CyclesRender_PT_performance(CyclesButtonsPanel, Panel):
         sub.label(text="Viewport:")
         sub.prop(cscene, "preview_start_resolution")
 
+        sub = col.column(align=True)
+        sub.label(text="Final Render:")
+        sub.prop(cscene, "use_persistent_images")
+
 
 class CyclesRender_PT_layers(CyclesButtonsPanel, Panel):
     bl_label = "Layers"