This commit adds memory usage information while rendering.
It reports memory used by device, meaning:
- For CPU it'll report real memory consumption
- For GPU rendering it'll report GPU memory consumption, but it'll
also mean the same memory is used from host side.
This information displays information about memory requested by Cycles,
not memory really allocated on a device. Real memory usage might be
higher because of memory fragmentation or optimistic memory allocator.
There's really nothing we can do against this.
Also in contrast with blender internal's render cycles memory usage
does not include memory used by scene, only memory needed by cycles
itself will be displayed. So don't freak out if memory usage reported
by cycles would be much lower than blender internal's.
This commit also adds RenderEngine.update_memory_stats callback which
is used to tell memory consumption from external engine to blender.
This information is used to generate information line after rendering
is finished.
The rendering device is now set in User Preferences > System, where you can
choose between OpenCL/CUDA and devices. Per scene you can then still choose
to use CPU or GPU rendering.
Load balancing still needs to be improved, now it just splits the entire
render in two, that will be done in a separate commit.
* 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.
Some notes about code status:
* The Blender modifications were fairly quickly put together, much more code
polish and work is needed to get this to a state where it can be committed
to trunk. Files created with this version may not work in future versions.
* Only simple path tracing is supported currently, but we intend to provide
finer control, and more options where it makes sense.
* For GPU rendering, only CUDA works currently. The intention is to have the
same kernel code compile for C++/OpenCL/CUDA, some more work is needed to
get OpenCL functional.
* There are two shading backends: GPU compatible and Open Shading Language.
Unfortunately, OSL only runs on the CPU currently, getting this to run on
the GPU would be a major undertaking, and is unlikely to be supported soon.
Additionally, it's not possible yet to write custom OSL shaders.
* There is some code for adaptive subdivision and displacement, but it's far
from finished. The intention is to eventually have a nice unified bump and
displacement system.
* The code currently has a number of fairly heavy dependencies: Boost,
OpenImageIO, GLEW, GLUT, and optionally OSL, Partio. This makes it difficult
to compile, we'll try to eliminate some, it may take a while before it
becomes easy to compile this.
