Approximate Ambient Occlusion

=============================

A new approximate ambient occlusion method has been added, next to the
existing one based on raytracing. This method is specifically targetted
at use in animations, since it is inherently noise free, and so will
not flicker across frames.

http://www.blender.org/development/current-projects/changes-since-244/approximate-ambient-occlusion/
http://peach.blender.org/index.php/approximate-ambient-occlusion/

Further improvements are still needed, but it can be tested already. There
are still a number of known issues:

- Bias errors on backfaces.
- For performance, instanced object do not occlude currently.
- Sky textures don't work well, the derivatives for texture evaluation
  are not correct.
- Multiple passes do not work entirely correct (they are not accurate
  to begin with, but could be better).

4 files changed, 59 insertions, 0 deletions

diff --git a/source/blender/render/intern/include/occlusion.h b/source/blender/render/intern/include/occlusion.h
new file mode 100644
index 00000000000..3f10d50ab2e
--- /dev/null
+++ b/source/blender/render/intern/include/occlusion.h
@@ -0,0 +1,51 @@
+/* 
+ * $Id$
+ *
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * The Original Code is Copyright (C) 2008 Blender Foundation.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): Brecht Van Lommel.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef OCCLUSION_H
+#define OCCLUSION_H
+
+struct Render;
+struct ShadeInput;
+struct ShadeResult;
+struct RenderPart;
+struct ShadeSample;
+struct DerivedMesh;
+struct ObjectRen;
+
+void make_occ_tree(struct Render *re);
+void free_occ(struct Render *re);
+void sample_occ(struct Render *re, struct ShadeInput *shi);
+
+void cache_occ_samples(struct Render *re, struct RenderPart *pa, struct ShadeSample *ssamp);
+void free_occ_samples(struct Render *re, struct RenderPart *pa);
+
+void *cache_occ_mesh(struct Render *re, struct ObjectRen *obr, struct DerivedMesh *dm, float mat[][4]);
+
+#endif
+
diff --git a/source/blender/render/intern/include/render_types.h b/source/blender/render/intern/include/render_types.h
index e3a92912191..6124870d63e 100644
--- a/source/blender/render/intern/include/render_types.h
+++ b/source/blender/render/intern/include/render_types.h
@@ -158,6 +158,10 @@ struct Render
 	
 	/* octree tables and variables for raytrace */
 	void *raytree;
+
+	/* occlusion tree */
+	void *occlusiontree;
+	ListBase occlusionmesh;
 	
 	/* use this instead of R.r.cfra */
 	float cfra;	
@@ -341,6 +345,7 @@ typedef struct StrandBuffer {
 
 	struct ObjectRen *obr;
 	struct Material *ma;
+	void *occlusionmesh;
 	unsigned int lay;
 	int overrideuv;
 	int flag, maxdepth;
diff --git a/source/blender/render/intern/include/renderdatabase.h b/source/blender/render/intern/include/renderdatabase.h
index a3a3b4e5e4a..a74579acc4a 100644
--- a/source/blender/render/intern/include/renderdatabase.h
+++ b/source/blender/render/intern/include/renderdatabase.h
@@ -70,6 +70,7 @@ typedef struct StrandTableNode {
 	float *winspeed;
 	float *surfnor;
 	float *simplify;
+	int *face;
 	struct MCol *mcol;
 	float *uv;
 	int totuv, totmcol;
@@ -114,6 +115,7 @@ float *RE_strandren_get_surfnor(struct ObjectRen *obr, struct StrandRen *strand,
 float *RE_strandren_get_uv(struct ObjectRen *obr, struct StrandRen *strand, int n, char **name, int verify);
 struct MCol *RE_strandren_get_mcol(struct ObjectRen *obr, struct StrandRen *strand, int n, char **name, int verify);
 float *RE_strandren_get_simplify(struct ObjectRen *obr, struct StrandRen *strand, int verify);
+int *RE_strandren_get_face(struct ObjectRen *obr, struct StrandRen *strand, int verify);
 float *RE_strandren_get_winspeed(struct ObjectInstanceRen *obi, struct StrandRen *strand, int verify);
 
 struct VertRen *RE_vertren_copy(struct ObjectRen *obr, struct VertRen *ver);
diff --git a/source/blender/render/intern/include/shading.h b/source/blender/render/intern/include/shading.h
index 6ca63a2976d..e3ffe5ef28f 100644
--- a/source/blender/render/intern/include/shading.h
+++ b/source/blender/render/intern/include/shading.h
@@ -69,6 +69,7 @@ void shade_input_initialize(struct ShadeInput *shi, struct RenderPart *pa, struc
 
 void shade_sample_initialize(struct ShadeSample *ssamp, struct RenderPart *pa, struct RenderLayer *rl);
 void shade_samples_do_AO(struct ShadeSample *ssamp);
+void shade_samples_fill_with_ps(struct ShadeSample *ssamp, struct PixStr *ps, int x, int y);
 int shade_samples(struct ShadeSample *ssamp, struct PixStr *ps, int x, int y);
 
 void vlr_set_uv_indices(struct VlakRen *vlr, int *i1, int *i2, int *i3);