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.
Regular rendering now works tiled, and supports save buffers to save memory
during render and cache render results.
Brick texture node by Thomas.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Textures#Brick_Texture
Image texture Blended Box Mapping.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Textures#Image_Texturehttp://mango.blender.org/production/blended_box/
Various bug fixes by Sergey and Campbell.
* Fix for reading freed memory in some node setups.
* Fix incorrect memory read when synchronizing mesh motion.
* Fix crash appearing when direct light usage is different on different layers.
* Fix for vector pass gives wrong result in some circumstances.
* Fix for wrong resolution used for rendering Render Layer node.
* Option to cancel rendering when doing initial synchronization.
* No more texture limit when using CPU render.
* Many fixes for new tiled rendering.
* Passes renamed to samples
* Camera lens radius renamed to aperature size/blades/rotation
* Glass and fresnel nodes input is now index of refraction
* Glossy and velvet fresnel socket removed
* Mix/add closure node renamed to mix/add shader node
* Blend weight node added for shader mixing weights
There is some version patching code for reading existing files, but it's not
perfect, so shaders may work a bit different.
