Cycles: merging features from tomato branch.

=== BVH build time optimizations ===

* BVH building was multithreaded. Not all building is multithreaded, packing
  and the initial bounding/splitting is still single threaded, but recursive
  splitting is, which was the main bottleneck.

* Object splitting now uses binning rather than sorting of all elements, using
  code from the Embree raytracer from Intel.
  http://software.intel.com/en-us/articles/embree-photo-realistic-ray-tracing-kernels/

* Other small changes to avoid allocations, pack memory more tightly, avoid
  some unnecessary operations, ...

These optimizations do not work yet when Spatial Splits are enabled, for that
more work is needed. There's also other optimizations still needed, in
particular for the case of many low poly objects, the packing step and node
memory allocation.

BVH raytracing time should remain about the same, but BVH build time should be
significantly reduced, test here show speedup of about 5x to 10x on a dual core
and 5x to 25x on an 8-core machine, depending on the scene.

=== Threads ===

Centralized task scheduler for multithreading, which is basically the
CPU device threading code wrapped into something reusable.

Basic idea is that there is a single TaskScheduler that keeps a pool of threads,
one for each core. Other places in the code can then create a TaskPool that they
can drop Tasks in to be executed by the scheduler, and wait for them to complete
or cancel them early.

=== Normal ====

Added a Normal output to the texture coordinate node. This currently
gives the object space normal, which is the same under object animation.

In the future this might become a "generated" normal so it's also stable for
deforming objects, but for now it's already useful for non-deforming objects.

=== Render Layers ===

Per render layer Samples control, leaving it to 0 will use the common scene
setting.

Environment pass will now render environment even if film is set to transparent.

Exclude Layers" added. Scene layers (all object that influence the render,
directly or indirectly) are shared between all render layers. However sometimes
it's useful to leave out some object influence for a particular render layer.
That's what this option allows you to do.

=== Filter Glossy ===

When using a value higher than 0.0, this will blur glossy reflections after
blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good
starting value to tweak.

Some light paths have a low probability of being found while contributing much
light to the pixel. As a result these light paths will be found in some pixels
and not in others, causing fireflies. An example of such a difficult path might
be a small light that is causing a small specular highlight on a sharp glossy
material, which we are seeing through a rough glossy material. With path tracing
it is difficult to find the specular highlight, but if we increase the roughness
on the material the highlight gets bigger and softer, and so easier to find.

Often this blurring will be hardly noticeable, because we are seeing it through
a blurry material anyway, but there are also cases where this will lead to a
loss of detail in lighting.

1 files changed, 35 insertions, 75 deletions

diff --git a/intern/cycles/bvh/bvh_build.h b/intern/cycles/bvh/bvh_build.h
index 1fa1951d7f2..84e14632b4b 100644
--- a/intern/cycles/bvh/bvh_build.h
+++ b/intern/cycles/bvh/bvh_build.h
@@ -21,8 +21,10 @@
 #include <float.h>
 
 #include "bvh.h"
+#include "bvh_binning.h"
 
 #include "util_boundbox.h"
+#include "util_task.h"
 #include "util_vector.h"
 
 CCL_NAMESPACE_BEGIN
@@ -37,28 +39,7 @@ class Progress;
 class BVHBuild
 {
 public:
-	struct Reference
-	{
-		int prim_index;
-		int prim_object;
-		BoundBox bounds;
-
-		Reference()
-		{
-		}
-	};
-
-	struct NodeSpec
-	{
-		int num;
-		BoundBox bounds;
-
-		NodeSpec()
-		{
-			num = 0;
-		}
-	};
-
+	/* Constructor/Destructor */
 	BVHBuild(
 		const vector<Object*>& objects,
 		vector<int>& prim_index,
@@ -70,63 +51,37 @@ public:
 	BVHNode *run();
 
 protected:
+	friend class BVHMixedSplit;
+	friend class BVHObjectSplit;
+	friend class BVHSpatialSplit;
+
 	/* adding references */
-	void add_reference_mesh(NodeSpec& root, Mesh *mesh, int i);
-	void add_reference_object(NodeSpec& root, Object *ob, int i);
-	void add_references(NodeSpec& root);
+	void add_reference_mesh(BoundBox& root, BoundBox& center, Mesh *mesh, int i);
+	void add_reference_object(BoundBox& root, BoundBox& center, Object *ob, int i);
+	void add_references(BVHRange& root);
 
 	/* building */
-	BVHNode *build_node(const NodeSpec& spec, int level, float progress_start, float progress_end);
-	BVHNode *create_leaf_node(const NodeSpec& spec);
-	BVHNode *create_object_leaf_nodes(const Reference *ref, int num);
-
-	void progress_update(float progress_start, float progress_end);
-
-	/* object splits */
-	struct ObjectSplit
-	{
-		float sah;
-		int dim;
-		int num_left;
-		BoundBox left_bounds;
-		BoundBox right_bounds;
-
-		ObjectSplit()
-		: sah(FLT_MAX), dim(0), num_left(0)
-		{
-		}
-	};
-
-	ObjectSplit find_object_split(const NodeSpec& spec, float nodeSAH);
-	void do_object_split(NodeSpec& left, NodeSpec& right, const NodeSpec& spec, const ObjectSplit& split);
-
-	/* spatial splits */
-	struct SpatialSplit
-	{
-		float sah;
-		int dim;
-		float pos;
-
-		SpatialSplit()
-		: sah(FLT_MAX), dim(0), pos(0.0f)
-		{
-		}
-	};
-
-	struct SpatialBin
-	{
-		BoundBox bounds;
-		int enter;
-		int exit;
-	};
-
-	SpatialSplit find_spatial_split(const NodeSpec& spec, float nodeSAH);
-	void do_spatial_split(NodeSpec& left, NodeSpec& right, const NodeSpec& spec, const SpatialSplit& split);
-	void split_reference(Reference& left, Reference& right, const Reference& ref, int dim, float pos);
+	BVHNode *build_node(const BVHRange& range, int level);
+	BVHNode *build_node(const BVHObjectBinning& range, int level);
+	BVHNode *create_leaf_node(const BVHRange& range);
+	BVHNode *create_object_leaf_nodes(const BVHReference *ref, int start, int num);
+
+	/* threads */
+	enum { THREAD_TASK_SIZE = 4096 };
+	void thread_build_node(Task *task_, int thread_id);
+	thread_mutex build_mutex;
+
+	/* progress */
+	void progress_update();
+
+	/* tree rotations */
+	void rotate(BVHNode *node, int max_depth);
+	void rotate(BVHNode *node, int max_depth, int iterations);
 
 	/* objects and primitive references */
 	vector<Object*> objects;
-	vector<Reference> references;
+	vector<BVHReference> references;
+	int num_original_references;
 
 	/* output primitive indexes and objects */
 	vector<int>& prim_index;
@@ -138,12 +93,17 @@ protected:
 	/* progress reporting */
 	Progress& progress;
 	double progress_start_time;
-	int progress_num_duplicates;
+	size_t progress_count;
+	size_t progress_total;
+	size_t progress_original_total;
 
 	/* spatial splitting */
 	float spatial_min_overlap;
 	vector<BoundBox> spatial_right_bounds;
-	SpatialBin spatial_bins[3][BVHParams::NUM_SPATIAL_BINS];
+	BVHSpatialBin spatial_bins[3][BVHParams::NUM_SPATIAL_BINS];
+
+	/* threads */
+	TaskPool task_pool;
 };
 
 CCL_NAMESPACE_END