* Volume Rendering: Voxel data

This commit introduces a new texture ('Voxel Data'), used to load up saved voxel 
data sets for rendering, contributed by Raúl 'farsthary' Fernández Hernández 
with some additional tweaks. Thanks, Raúl!

The texture works similar to the existing point density texture, currently it 
only provides intensity information, which can then be mapped (for example) to 
density in a volume material. This is an early version, intended to read the 
voxel format saved by Raúl's command line simulators, in future revisions 
there's potential for making a more full-featured 'Blender voxel file format', 
and also for supporting other formats too.

Note: Due to some subtleties in Raúl's existing released simulators, in  order 
to load them correctly the voxel data texture, you'll need to raise the 
'resolution' value by 2. So if you baked out the simulation at resolution 50, 
enter 52 for the resolution in the texture panel. This can possibly be fixed in 
the simulator later on.

Right now, the way the texture is mapped is just in the space 0,0,0 <-> 1,1,1 
and it can appear rotated 90 degrees incorrectly. This will be tackled, for now, 
probably the easiest way to map it is with and empty, using Map Input -> Object.

Smoke test: http://www.vimeo.com/2449270

One more note, trilinear interpolation seems a bit slow at the moment, we'll 
look into this.

For curiosity, while testing/debugging this, I made a script that exports a mesh 
to voxel data. Here's a test of grogan (www.kajimba.com) converted to voxels, 
rendered as a volume: http://www.vimeo.com/2512028

The script is available here: http://mke3.net/projects/bpython/export_object_voxeldata.py

* Another smaller thing, brought back early ray termination (was disabled 
previously for debugging) and made it user configurable. It now appears as a new 
value in the volume material: 'Depth Cutoff'. For some background info on what 
this does, check:
http://farsthary.wordpress.com/2008/12/11/cutting-down-render-times/

* Also some disabled work-in-progess code for light cache

15 files changed, 324 insertions, 57 deletions

diff --git a/source/blender/blenkernel/BKE_texture.h b/source/blender/blenkernel/BKE_texture.h
index e16ac2d369b..985094a7e62 100644
--- a/source/blender/blenkernel/BKE_texture.h
+++ b/source/blender/blenkernel/BKE_texture.h
@@ -40,6 +40,7 @@ struct HaloRen;
 struct TexMapping;
 struct EnvMap;
 struct PointDensity;
+struct VoxelData;
 
 /*  in ColorBand struct */
 #define MAXCOLORBAND 32
@@ -80,6 +81,11 @@ void    BKE_free_pointdensity(struct PointDensity *pd);
 struct PointDensity *BKE_add_pointdensity(void);
 struct PointDensity *BKE_copy_pointdensity(struct PointDensity *pd);
 
+void BKE_free_voxeldatadata(struct VoxelData *vd);
+void BKE_free_voxeldata(struct VoxelData *vd);
+struct VoxelData *BKE_add_voxeldata(void);
+struct VoxelData *BKE_copy_voxeldata(struct VoxelData *vd);
+
 int     BKE_texture_dependsOnTime(const struct Tex *texture);
 
 #endif
diff --git a/source/blender/blenkernel/intern/texture.c b/source/blender/blenkernel/intern/texture.c
index c972d70d927..c9cae91da6f 100644
--- a/source/blender/blenkernel/intern/texture.c
+++ b/source/blender/blenkernel/intern/texture.c
@@ -420,6 +420,7 @@ void free_texture(Tex *tex)
 	if(tex->coba) MEM_freeN(tex->coba);
 	if(tex->env) BKE_free_envmap(tex->env);
 	if(tex->pd) BKE_free_pointdensity(tex->pd);
+	if(tex->vd) BKE_free_voxeldata(tex->vd);
 	BKE_previewimg_free(&tex->preview);
 	BKE_icon_delete((struct ID*)tex);
 	tex->id.icon_id = 0;
@@ -490,6 +491,11 @@ void default_tex(Tex *tex)
 		tex->pd->radius = 0.3f;
 		tex->pd->falloff_type = TEX_PD_FALLOFF_STD;
 	}
+	
+	if (tex->vd) {
+		tex->vd->resolX=50;
+		tex->vd->interp_type=0;
+	}
 
 	pit = tex->plugin;
 	if (pit) {
@@ -588,6 +594,7 @@ Tex *copy_texture(Tex *tex)
 	if(texn->coba) texn->coba= MEM_dupallocN(texn->coba);
 	if(texn->env) texn->env= BKE_copy_envmap(texn->env);
 	if(texn->pd) texn->pd= BKE_copy_pointdensity(texn->pd);
+	if(texn->vd) texn->vd=BKE_copy_voxeldata(texn->vd);
 	
 	if(tex->preview) texn->preview = BKE_previewimg_copy(tex->preview);
 
@@ -945,6 +952,48 @@ void BKE_free_pointdensity(PointDensity *pd)
 	MEM_freeN(pd);
 }
 
+
+void BKE_free_voxeldatadata(struct VoxelData *vd)
+{
+	if (vd->dataset) {
+		MEM_freeN(vd->dataset);
+		vd->dataset = NULL;
+	}
+
+}
+ 
+void BKE_free_voxeldata(struct VoxelData *vd)
+{
+	BKE_free_voxeldatadata(vd);
+	MEM_freeN(vd);
+}
+ 
+struct VoxelData *BKE_add_voxeldata(void)
+{
+	VoxelData *vd;
+
+	vd= MEM_callocN(sizeof(struct VoxelData), "voxeldata");
+	vd->dataset = NULL;
+	vd->resolX = 1;
+	vd->resolY = 1;
+	vd->resolZ = 1;
+	vd->interp_type= TEX_VD_NEARESTNEIGHBOR;
+	vd->int_multiplier = 1.0;
+	
+	return vd;
+ }
+ 
+struct VoxelData *BKE_copy_voxeldata(struct VoxelData *vd)
+{
+	VoxelData *vdn;
+
+	vdn= MEM_dupallocN(vd);	
+	vdn->dataset = NULL;
+
+	return vdn;
+}
+
+
 /* ------------------------------------------------------------------------- */
 int BKE_texture_dependsOnTime(const struct Tex *texture)
 {
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 1fd766be256..8347920319a 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -2535,6 +2535,11 @@ static void direct_link_texture(FileData *fd, Tex *tex)
 		tex->pd->coba= newdataadr(fd, tex->pd->coba);
 	}
 	
+	tex->vd= newdataadr(fd, tex->vd);
+	if(tex->vd) {
+		tex->vd->dataset = NULL;
+	}
+	
 	tex->nodetree= newdataadr(fd, tex->nodetree);
 	if(tex->nodetree)
 		direct_link_nodetree(fd, tex->nodetree);
@@ -7939,6 +7944,8 @@ static void do_versions(FileData *fd, Library *lib, Main *main)
 				ma->vol_density_scale = 1.0f;
 			if (ma->vol_precache_resolution == 0)
 				ma->vol_precache_resolution = 50;
+			if (ma->vol_depth_cutoff < 0.0001)
+				ma->vol_depth_cutoff = 0.05;
 		}
 		
 		for(tex=main->tex.first; tex; tex= tex->id.next) {
@@ -7956,6 +7963,17 @@ static void do_versions(FileData *fd, Library *lib, Main *main)
 				tex->pd->coba = add_colorband(1);
 				tex->pd->speed_scale = 1.0f;
 			}
+			
+			if (tex->vd == NULL) {
+				tex->vd = BKE_add_voxeldata();
+			} else if (tex->vd->resolX == 0) {
+				tex->vd->dataset = NULL;
+				tex->vd->resolX = 1;
+				tex->vd->resolY = 1;
+				tex->vd->resolZ = 1;
+				tex->vd->interp_type= TEX_VD_NEARESTNEIGHBOR;
+				tex->vd->int_multiplier = 1.0;
+			}
 		}
 		
 	}
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index 93bf8111c98..fd87080d0ee 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -1339,6 +1339,7 @@ static void write_textures(WriteData *wd, ListBase *idbase)
 				writestruct(wd, DATA, "PointDensity", 1, tex->pd);
 				if(tex->pd->coba) writestruct(wd, DATA, "ColorBand", 1, tex->pd->coba);
 			}
+			if(tex->vd) writestruct(wd, DATA, "VoxelData", 1, tex->vd);
 			
 			/* nodetree is integral part of texture, no libdata */
 			if(tex->nodetree) {
diff --git a/source/blender/include/butspace.h b/source/blender/include/butspace.h
index fd3f6e926b9..a3cd9d1875b 100644
--- a/source/blender/include/butspace.h
+++ b/source/blender/include/butspace.h
@@ -260,6 +260,8 @@ void curvemap_buttons(struct uiBlock *block, struct CurveMapping *cumap, char la
 #define B_ENV_FREE_ALL	1357
 #define B_TEX_USENODES		1358
 
+#define B_VOXELDATA_LOAD	1359
+
 
 /* **************** animbuts = object buttons ******* */
 #define B_ANIMBUTS		1500
diff --git a/source/blender/makesdna/DNA_material_types.h b/source/blender/makesdna/DNA_material_types.h
index f332537e9a8..5172f6a970c 100644
--- a/source/blender/makesdna/DNA_material_types.h
+++ b/source/blender/makesdna/DNA_material_types.h
@@ -69,6 +69,8 @@ typedef struct Material {
 	short vol_stepsize_type;
 	short vol_precache_resolution;
 	float vol_stepsize, vol_shade_stepsize;
+	float vol_depth_cutoff;
+	float vpad;
 	float vol_density_scale;
 	float vol_absorption, vol_scattering;
 	float vol_absorption_col[3];
diff --git a/source/blender/makesdna/DNA_texture_types.h b/source/blender/makesdna/DNA_texture_types.h
index b4fcb5efe40..e90df908c2b 100644
--- a/source/blender/makesdna/DNA_texture_types.h
+++ b/source/blender/makesdna/DNA_texture_types.h
@@ -154,7 +154,7 @@ typedef struct PointDensity {
 	short noise_depth;
 	short noise_influence;
 	short noise_basis;
-	short pdpad3[3];
+    short pdpad3[3];
 	float noise_fac;
 	
 	float speed_scale;
@@ -162,6 +162,18 @@ typedef struct PointDensity {
 	
 } PointDensity;
 
+typedef struct VoxelData {
+	int resolX, resolY, resolZ;
+	int interp_type;
+
+	float int_multiplier;
+	float vxpad;
+	
+	char source_path[240];
+	float *dataset;
+ 
+} VoxelData;
+
 typedef struct Tex {
 	ID id;
 	
@@ -209,6 +221,7 @@ typedef struct Tex {
 	struct EnvMap *env;
 	struct PreviewImage * preview;
 	struct PointDensity *pd;
+	struct VoxelData *vd;
 	
 	char use_nodes;
 	char pad[7];
@@ -250,6 +263,7 @@ typedef struct TexMapping {
 #define TEX_DISTNOISE	13
 /* predicting ocean texture for 14 */
 #define TEX_POINTDENSITY	15
+#define TEX_VOXELDATA		16
 
 /* musgrave stype */
 #define TEX_MFRACTAL		0
@@ -465,5 +479,13 @@ typedef struct TexMapping {
 #define POINT_DATA_VEL		1
 #define POINT_DATA_LIFE		2
 
+/******************** Voxel Data *****************************/ 
+#define TEX_VD_CUBIC              0
+#define TEX_VD_PARALLELOGRAM      1
+ 
+#define TEX_VD_NEARESTNEIGHBOR		0
+#define TEX_VD_LINEAR			1
+#define TEX_VD_TRICUBIC				2
+
 #endif
 
diff --git a/source/blender/render/intern/include/render_types.h b/source/blender/render/intern/include/render_types.h
index 6f4537d84fb..65bb12e059d 100644
--- a/source/blender/render/intern/include/render_types.h
+++ b/source/blender/render/intern/include/render_types.h
@@ -203,6 +203,8 @@ struct Render
 	struct Object *excludeob;
 	
 	ListBase vol_precache_obs;
+	ListBase render_volumes_inside;
+	ListBase volumes;
 
 	/* arena for allocating data for use during render, for
 		* example dynamic TFaces to go in the VlakRen structure.
@@ -409,6 +411,18 @@ typedef struct VolPrecache
 	struct ObjectRen *obr;
 } VolPrecache;
 
+typedef struct VolumeOb
+{
+	struct VolumeOb *next, *prev;
+	struct Material *ma;
+	struct ObjectRen *obr;
+} VolumeOb;
+
+typedef struct MatInside {
+	struct MatInside *next, *prev;
+	struct Material *ma;
+} MatInside;
+
 /* ------------------------------------------------------------------------- */
 
 struct LampRen;
diff --git a/source/blender/render/intern/include/volume_precache.h b/source/blender/render/intern/include/volume_precache.h
index 7a719840f48..78409e4c646 100644
--- a/source/blender/render/intern/include/volume_precache.h
+++ b/source/blender/render/intern/include/volume_precache.h
@@ -27,4 +27,5 @@
  */
  
 void volume_precache(Render *re);
-void free_volume_precache(Render *re);
\ No newline at end of file
+void free_volume_precache(Render *re);
+int point_inside_volume_objectinstance(ObjectInstanceRen *obi, float *co);
\ No newline at end of file
diff --git a/source/blender/render/intern/source/convertblender.c b/source/blender/render/intern/source/convertblender.c
index 09f2d1275f4..d87ee65c42c 100644
--- a/source/blender/render/intern/source/convertblender.c
+++ b/source/blender/render/intern/source/convertblender.c
@@ -104,6 +104,7 @@
 #include "multires.h"
 #include "occlusion.h"
 #include "pointdensity.h"
+#include "voxeldata.h"
 #include "render_types.h"
 #include "rendercore.h"
 #include "renderdatabase.h"
@@ -3028,16 +3029,51 @@ static void use_mesh_edge_lookup(ObjectRen *obr, DerivedMesh *dm, MEdge *medge,
 	}
 }
 
-static void add_vol_precache(Render *re, ObjectRen *obr, Material *ma)
+static void free_camera_inside_volumes(Render *re)
 {
-	struct VolPrecache *vp;
+	BLI_freelistN(&re->render_volumes_inside);
+}
+
+static void init_camera_inside_volumes(Render *re)
+{
+	ObjectInstanceRen *obi;
+	VolumeOb *vo;
+	float co[3] = {0.f, 0.f, 0.f};
+
+	for(vo= re->volumes.first; vo; vo= vo->next) {
+		for(obi= re->instancetable.first; obi; obi= obi->next) {
+			if (obi->obr == vo->obr) {
+				if (point_inside_volume_objectinstance(obi, co)) {
+					MatInside *mi;
+					
+					mi = MEM_mallocN(sizeof(MatInside), "camera inside material");
+					mi->ma = vo->ma;
+					
+					BLI_addtail(&(re->render_volumes_inside), mi);
+				}
+			}
+		}
+	}
+	
+	{
+	MatInside *m;
+	for (m=re->render_volumes_inside.first; m; m=m->next) {
+		printf("matinside: ma: %s \n", m->ma->id.name+2);
+	}
 	
-	vp = MEM_mallocN(sizeof(VolPrecache), "volume precache object");
+	}
+}
+
+static void add_volume(Render *re, ObjectRen *obr, Material *ma)
+{
+	struct VolumeOb *vo;
 	
-	vp->ma = ma;
-	vp->obr = obr;
+	vo = MEM_mallocN(sizeof(VolumeOb), "volume object");
 	
-	BLI_addtail(&re->vol_precache_obs, vp);
+	vo->ma = ma;
+	vo->obr = obr;
+	
+	BLI_addtail(&re->volumes, vo);
 }
 
 static void init_render_mesh(Render *re, ObjectRen *obr, int timeoffset)
@@ -3095,9 +3131,8 @@ static void init_render_mesh(Render *re, ObjectRen *obr, int timeoffset)
 				if(ma->mode & MA_RADIO) 
 					do_autosmooth= 1;
 			
-			if ((ma->material_type == MA_VOLUME) && (ma->vol_shadeflag & MA_VOL_PRECACHESHADING)) {
-				add_vol_precache(re, obr, ma);
-			}
+			if (ma->material_type == MA_VOLUME)
+				add_volume(re, obr, ma);
 		}
 	}
 
@@ -4457,6 +4492,9 @@ void RE_Database_Free(Render *re)
 	end_render_textures();
 	
 	free_pointdensities(re);
+	free_voxeldata(re);
+	
+	free_camera_inside_volumes(re);
 	
 	if(re->wrld.aosphere) {
 		MEM_freeN(re->wrld.aosphere);
@@ -4861,6 +4899,8 @@ void RE_Database_FromScene(Render *re, Scene *scene, int use_camera_view)
 
 	/* MAKE RENDER DATA */
 	database_init_objects(re, lay, 0, 0, 0, 0);
+	
+	init_camera_inside_volumes(re);
 
 	if(!re->test_break()) {
 		int tothalo;
@@ -4912,6 +4952,9 @@ void RE_Database_FromScene(Render *re, Scene *scene, int use_camera_view)
 			/* point density texture */
 			if(!re->test_break())
 				make_pointdensities(re);
+			/* voxel data texture */
+			if(!re->test_break())
+				make_voxeldata(re);//Volumetrics
 		}
 		
 		if(!re->test_break())
diff --git a/source/blender/render/intern/source/texture.c b/source/blender/render/intern/source/texture.c
index d7d4d124b18..d7b41d7cc2c 100644
--- a/source/blender/render/intern/source/texture.c
+++ b/source/blender/render/intern/source/texture.c
@@ -65,6 +65,7 @@
 
 #include "envmap.h"
 #include "pointdensity.h"
+#include "voxeldata.h"
 #include "renderpipeline.h"
 #include "render_types.h"
 #include "rendercore.h"
@@ -1257,6 +1258,10 @@ static int multitex(Tex *tex, float *texvec, float *dxt, float *dyt, int osatex,
 	case TEX_POINTDENSITY:
 		retval= pointdensitytex(tex, texvec, texres);
 		break;
+	case TEX_VOXELDATA:
+		retval= voxeldatatex(tex, texvec, texres);  
+		break;
+
 	}
 
 	if (tex->flag & TEX_COLORBAND) {
diff --git a/source/blender/render/intern/source/volume_precache.c b/source/blender/render/intern/source/volume_precache.c
index 246f9bc6d69..89f997f4b99 100644
--- a/source/blender/render/intern/source/volume_precache.c
+++ b/source/blender/render/intern/source/volume_precache.c
@@ -400,7 +400,7 @@ static void *vol_precache_part(void *data)
 	return 0;
 }
 
-void precache_setup_shadeinput(Render *re, ObjectInstanceRen *obi, Material *ma, ShadeInput *shi)
+static void precache_setup_shadeinput(Render *re, ObjectInstanceRen *obi, Material *ma, ShadeInput *shi)
 {
 	float view[3] = {0.0,0.0,-1.0};
 	
@@ -417,6 +417,34 @@ void precache_setup_shadeinput(Render *re, ObjectInstanceRen *obi, Material *ma,
 	VECCOPY(shi->view, view);
 }
 
+static void precache_init_parts(ListBase *precache_parts, RayTree *tree, ShadeInput *shi, ObjectInstanceRen *obi, float *bbmin, float *bbmax, int res)
+{
+	int i;
+	float voxel[3];
+
+	VecSubf(voxel, bbmax, bbmin);
+	if ((voxel[0] < FLT_EPSILON) || (voxel[1] < FLT_EPSILON) || (voxel[2] < FLT_EPSILON))
+		return;
+	VecMulf(voxel, 1.0f/res);
+
+	for(i=0; i < totparts; i++) {
+		VolPrecachePart *pa= MEM_callocN(sizeof(VolPrecachePart), "new precache part");
+	
+		pa->done = 0;
+		pa->num = i;
+		
+		pa->res = res;
+		VECCOPY(pa->bbmin, bbmin);
+		VECCOPY(precache_parts[j].voxel, voxel);
+		precache_parts[j].tree = tree;
+		precache_parts[j].shi = shi;
+		precache_parts[j].obi = obi;
+		
+		BLI_addtail(precache_parts, pa);
+	}
+	
+}
+
 void vol_precache_objectinstance_threads(Render *re, ObjectInstanceRen *obi, Material *ma, float *bbmin, float *bbmax)
 {
 	int x, y, z;
@@ -431,13 +459,12 @@ void vol_precache_objectinstance_threads(Render *re, ObjectInstanceRen *obi, Mat
 	int res_2, res_3;
 	
 	int edgeparts=2;
-	int totparts;
-	ListBase threads;
+	ListBase threads, precache_parts;
 	int cont= 1;
 	int xparts, yparts, zparts;
 	float part[3];
 	int totthread = re->r.threads;
-	ListBase precache_parts;
+	int totparts = edgeparts*edgeparts*edgeparts;
 	VolPrecachePart *nextpa;
 	int j;
 	
@@ -452,41 +479,13 @@ void vol_precache_objectinstance_threads(Render *re, ObjectInstanceRen *obi, Mat
 	 * used for checking if the cached point is inside or outside. */
 	tree = create_raytree_obi(obi, bbmin, bbmax);
 	if (!tree) return;
-
-	/* Need a shadeinput to calculate scattering */
-	precache_setup_shadeinput(re, obi, ma, &shi);
-
-	VecSubf(voxel, bbmax, bbmin);
-	if ((voxel[0] < FLT_EPSILON) || (voxel[1] < FLT_EPSILON) || (voxel[2] < FLT_EPSILON))
-		return;
-	VecMulf(voxel, 1.0f/res);
-	
-	part[0] = ceil(res/(float)xparts); 
-	part[1] = ceil(res/(float)yparts);
-	part[2] = ceil(res/(float)zparts);
 	
 	obi->volume_precache = MEM_callocN(sizeof(float)*res_3*3, "volume light cache");
-	
-	totparts = edgeparts*edgeparts*edgeparts;
-	precache_parts= MEM_callocN(sizeof(VolPrecachePart)*totparts, "VolPrecachePart");
-	memset(precache_parts, 0, sizeof(VolPrecachePart)*totparts);
 
-	precache_init_parts(precache_parts);
+	/* Need a shadeinput to calculate scattering */
+	precache_setup_shadeinput(re, obi, ma, &shi);
+	precache_init_parts(&precache_parts, tree, shi, obi, bbmin, bbmax, res);
 
-	for(j=0; j < totparts; j++) {
-		VolPrecachePart *pa= MEM_callocN(sizeof(VolPrecachePart), "new precache part");
-	
-		pa->done = 0;
-		pa->num = j;
-		
-		pa->res = res;
-		VECCOPY(pa->bbmin, bbmin);
-		VECCOPY(precache_parts[j].voxel, voxel);
-		precache_parts[j].tree = tree;
-		precache_parts[j].shi = shi;
-		precache_parts[j].obi = obi;
-	}
-	
 	BLI_init_threads(&threads, vol_precache_part, totthread);
 	
 	nextpa = precache_get_new_part(precache_threads);
@@ -600,12 +599,15 @@ void vol_precache_objectinstance_threads(Render *re, ObjectInstanceRen *obi, Mat
 void volume_precache(Render *re)
 {
 	ObjectInstanceRen *obi;
-	VolPrecache *vp;
+	VolumeOb *vo;
 
-	for(vp= re->vol_precache_obs.first; vp; vp= vp->next) {
-		for(obi= re->instancetable.first; obi; obi= obi->next) {
-			if (obi->obr == vp->obr) 
-				vol_precache_objectinstance(re, obi, vp->ma, obi->obr->boundbox[0], obi->obr->boundbox[1]);
+	for(vo= re->volumes.first; vo; vo= vo->next) {
+		if (vo->ma->vol_shadeflag & MA_VOL_PRECACHESHADING) {
+			for(obi= re->instancetable.first; obi; obi= obi->next) {
+				if (obi->obr == vo->obr) {
+					vol_precache_objectinstance(re, obi, vo->ma, obi->obr->boundbox[0], obi->obr->boundbox[1]);
+				}
+			}
 		}
 	}
 	
@@ -624,3 +626,19 @@ void free_volume_precache(Render *re)
 	
 	BLI_freelistN(&re->vol_precache_obs);
 }
+
+int point_inside_volume_objectinstance(ObjectInstanceRen *obi, float *co)
+{
+	RayTree *tree;
+	int inside=0;
+	
+	tree = create_raytree_obi(obi, obi->obr->boundbox[0], obi->obr->boundbox[1]);
+	if (!tree) return 0;
+	
+	inside = point_inside_obi(tree, obi, co);
+	
+	RE_ray_tree_free(tree);
+	tree= NULL;
+	
+	return inside;
+}
diff --git a/source/blender/render/intern/source/volumetric.c b/source/blender/render/intern/source/volumetric.c
index 45d54d40fa1..fba847da2ad 100644
--- a/source/blender/render/intern/source/volumetric.c
+++ b/source/blender/render/intern/source/volumetric.c
@@ -21,7 +21,7 @@
  *
  * The Original Code is: all of this file.
  *
- * Contributor(s): Matt Ebb, Raul Hernandez.
+ * Contributor(s): Matt Ebb, Raul Fernandez Hernandez (Farsthary)
  *
  * ***** END GPL LICENSE BLOCK *****
  */
@@ -134,6 +134,11 @@ float vol_get_stepsize(struct ShadeInput *shi, int context)
 	return shi->mat->vol_stepsize;
 }
 
+static float vol_get_depth_cutoff(struct ShadeInput *shi)
+{
+	return shi->mat->vol_depth_cutoff;
+}
+
 /* SHADING */
 
 static float D(ShadeInput *shi, int rgb, int x, int y, int z)
@@ -278,7 +283,7 @@ float vol_get_phasefunc(ShadeInput *shi, short phasefunc_type, float g, float *w
 void vol_get_absorption(ShadeInput *shi, float *absorb_col, float *co)
 {
 	float dummy = 1.0f;
-	float absorption = shi->mat->vol_absorption;
+	const float absorption = shi->mat->vol_absorption;
 	
 	VECCOPY(absorb_col, shi->mat->vol_absorption_col);
 	
@@ -296,14 +301,13 @@ void vol_get_absorption(ShadeInput *shi, float *absorb_col, float *co)
 void vol_get_attenuation(ShadeInput *shi, float *tau, float *co, float *endco, float density, float stepsize)
 {
 	/* input density = density at co */
-	float dist;
 	float absorb_col[3];
 	int s, nsteps;
 	float step_vec[3], step_sta[3], step_end[3];
+	const float dist = VecLenf(co, endco);
 
 	vol_get_absorption(shi, absorb_col, co);
 
-	dist = VecLenf(co, endco);
 	nsteps = (int)((dist / stepsize) + 0.5);
 	
 	/* trigger for recalculating density */
@@ -468,6 +472,7 @@ static void volumeintegrate(struct ShadeInput *shi, float *col, float *co, float
 	float tau[3], emit_col[3], scatter_col[3] = {0.0, 0.0, 0.0};
 	float stepvec[3], step_sta[3], step_end[3], step_mid[3];
 	float density = vol_get_density(shi, co);
+	const float depth_cutoff = vol_get_depth_cutoff(shi);
 	
 	/* multiply col_behind with beam transmittance over entire distance */
 	vol_get_attenuation(shi, tau, co, endco, density, stepsize);
@@ -524,6 +529,9 @@ static void volumeintegrate(struct ShadeInput *shi, float *col, float *co, float
 
 		VecCopyf(step_sta, step_end);
 		VecAddf(step_end, step_end, stepvec);
+		
+		/* luminance rec. 709 */
+		if ((0.2126*tr[0] + 0.7152*tr[1] + 0.0722*tr[2]) < depth_cutoff) break;	
 	}
 	
 	VecCopyf(col, radiance);
diff --git a/source/blender/src/butspace.c b/source/blender/src/butspace.c
index 2ca709184c5..6d8f806d8f9 100644
--- a/source/blender/src/butspace.c
+++ b/source/blender/src/butspace.c
@@ -92,7 +92,7 @@ MTex mtexcopybuf;
 
 char texstr[20][12]= {"None"  , "Clouds" , "Wood", "Marble", "Magic"  , "Blend",
 					 "Stucci", "Noise"  , "Image", "Plugin", "EnvMap" , "Musgrave",
-					 "Voronoi", "DistNoise", "", "PointDensity", "", "", "", ""};
+					 "Voronoi", "DistNoise", "", "PointDensity", "VoxelData", "", "", ""};
 /*  ---------------------------------------------------------------------- */
 
 void test_idbutton_cb(void *namev, void *arg2)
diff --git a/source/blender/src/buttons_shading.c b/source/blender/src/buttons_shading.c
index a8aa00370d9..6e69414fbe0 100644
--- a/source/blender/src/buttons_shading.c
+++ b/source/blender/src/buttons_shading.c
@@ -264,6 +264,19 @@ static int vergcband(const void *a1, const void *a2)
 	return 0;
 }
 
+static void voxeldata_filename(char *str, void *tex_v, void *unused)	/* called from fileselect */
+{
+	Tex *tex= tex_v;
+	
+	if(tex->type!=TEX_VOXELDATA) return;
+	
+	strcpy(tex->vd->source_path, str);
+	
+	allqueue(REDRAWBUTSSHADING, 0);
+	BIF_preview_changed(ID_TE);
+	BIF_undo_push("Open voxel data source");
+}
+
 void do_texbuts(unsigned short event)
 {
 	Tex *tex;
@@ -425,7 +438,25 @@ void do_texbuts(unsigned short event)
 		allqueue(REDRAWBUTSSHADING, 0);
 		allqueue(REDRAWIPO, 0);
 		break;
+	
+	case B_VOXELDATA_LOAD:
+		if (tex->vd==NULL) {
+			tex->vd= BKE_add_voxeldata();
+#ifdef _WIN32
+			if (strcmp (U.textudir, "/") == 0)
+				strcpy(str, G.sce);
+			else
+				strcpy(str, U.textudir);
+#else
+			strcpy(str, U.textudir);
+#endif
+		}
+		else strcpy(str, tex->vd->source_path);
 		
+		sa= closest_bigger_area();
+		areawinset(sa->win);
+		activate_fileselect_args(FILE_SPECIAL, "Open Voxel Data", str, voxeldata_filename, tex, NULL);
+		break;
 	default:
 		if(event>=B_PLUGBUT && event<=B_PLUGBUT+23) {
 			PluginTex *pit= tex->plugin;
@@ -1016,6 +1047,48 @@ static void texture_panel_pointdensity_modify(Tex *tex)
 
 }
 
+static void texture_panel_voxeldata(Tex *tex)
+{
+	uiBlock *block;
+	VoxelData *vd;
+	short yco=PANEL_YMAX;
+
+	block= uiNewBlock(&curarea->uiblocks, "texture_panel_voxeldata", UI_EMBOSS, UI_HELV, curarea->win);
+	if(uiNewPanel(curarea, block, "Voxel Data", "Texture", PANELX, PANELY, PANELW, PANELH)==0) return;
+	uiSetButLock(tex->id.lib!=0, ERROR_LIBDATA_MESSAGE);
+
+	if(tex->vd==NULL) {
+		tex->vd= BKE_add_voxeldata();
+	}
+
+	if(tex->vd) {
+		vd= tex->vd;
+		
+		uiDefBut(block, LABEL, B_NOP, "Data source:",
+			X2CLM1, yco-=BUTH, BUTW2, BUTH, 0, 0, 0, 0, 0, "");
+			
+		uiDefIconTextBut(block, BUT, B_VOXELDATA_LOAD, ICON_FILESEL, "Open",
+			X4CLM1, yco-=BUTH, BUTW4, BUTH, 0, 0, 0, 0, 0, "");
+		uiDefBut(block, TEX, 0, "",
+			X4CLM2+XSPACE, yco, BUTW2+BUTW4+2*XSPACE, BUTH, &vd->source_path, 0.0, 79.0, 0, 0, "File path to the voxel data set");
+
+		yco -= YSPACE;
+		
+		uiDefBut(block, LABEL, B_NOP, "Interpolation:",
+			X2CLM1, yco-=BUTH, BUTW2, BUTH, 0, 0, 0, 0, 0, "");
+		uiDefButI(block, MENU, B_REDR, "None %x0|Linear %x1|Tricubic %x2",
+			X2CLM1, yco-=BUTH, BUTW2, BUTH, &vd->interp_type, 0.0, 0.0, 0, 0, "Interpolation type");		
+		
+		uiDefButI(block, NUM, B_REDR, "Resolution: ",
+			X2CLM2, yco, BUTW2, BUTH, &(vd->resolX), 1, 10000, 0, 0, "Resolution of the voxel data");
+			
+		yco -= YSPACE;
+		
+		uiDefButF(block, NUM, B_REDR, "Intensity: ",
+			X2CLM1, yco-=BUTH, BUTW2, BUTH, &(vd->int_multiplier), 0.0001, 10000.0, 0, 0, "Multiplier to scale up or down the texture's intensity");
+	}
+}
+
 static char *layer_menu(RenderResult *rr, short *curlay)
 {
 	RenderLayer *rl;
@@ -1865,7 +1938,7 @@ static void texture_panel_texture(MTex *actmtex, Material *ma, World *wrld, Lamp
 		/* newnoise: all texture types as menu, not enough room for more buttons.
 		 * Can widen panel, but looks ugly when other panels overlap it */
 		if( !tex->use_nodes ) {
-			sprintf(textypes, "Texture Type %%t|None %%x%d|Image %%x%d|EnvMap %%x%d|Clouds %%x%d|Marble %%x%d|Stucci %%x%d|Wood %%x%d|Magic %%x%d|Blend %%x%d|Noise %%x%d|Plugin %%x%d|Musgrave %%x%d|Voronoi %%x%d|DistortedNoise %%x%d|Point Density %%x%d", 0, TEX_IMAGE, TEX_ENVMAP, TEX_CLOUDS, TEX_MARBLE, TEX_STUCCI, TEX_WOOD, TEX_MAGIC, TEX_BLEND, TEX_NOISE, TEX_PLUGIN, TEX_MUSGRAVE, TEX_VORONOI, TEX_DISTNOISE, TEX_POINTDENSITY);
+			sprintf(textypes, "Texture Type %%t|None %%x%d|Image %%x%d|EnvMap %%x%d|Clouds %%x%d|Marble %%x%d|Stucci %%x%d|Wood %%x%d|Magic %%x%d|Blend %%x%d|Noise %%x%d|Plugin %%x%d|Musgrave %%x%d|Voronoi %%x%d|DistortedNoise %%x%d|Point Density %%x%d|Voxel Data %%x%d", 0, TEX_IMAGE, TEX_ENVMAP, TEX_CLOUDS, TEX_MARBLE, TEX_STUCCI, TEX_WOOD, TEX_MAGIC, TEX_BLEND, TEX_NOISE, TEX_PLUGIN, TEX_MUSGRAVE, TEX_VORONOI, TEX_DISTNOISE, TEX_POINTDENSITY, TEX_VOXELDATA);
 			uiDefBut(block, LABEL, 0, "Texture Type",		160, 150, 140, 20, 0, 0.0, 0.0, 0, 0, "");
 			uiDefButS(block, MENU, B_TEXTYPE, textypes,	160, 125, 140, 25, &tex->type, 0,0,0,0, "Select texture type");
 		}
@@ -4449,6 +4522,8 @@ static void material_panel_material_volume(Material *ma)
 		X2CLM1, yco-=BUTH, BUTW2, BUTH, &(ma->vol_stepsize), 0.001, 100.0, 10, 2, "Ray marching step size");
 	uiDefButS(block, MENU, B_TEXREDR_PRV, "Step Size Calculation %t|Randomized %x0|Constant %x1",
 		X2CLM1, yco-=BUTH, BUTW2, BUTH, &ma->vol_stepsize_type, 0.0, 0.0, 0, 0, "Step size calculation, randomized replaces banding with jittering");
+	uiDefButF(block, NUM, B_MATPRV, "Depth Cutoff: ",
+		X2CLM1, yco-=BUTH, BUTW2, BUTH, &(ma->vol_depth_cutoff), 0.001, 1.0, 10, 2, "Stop ray marching early if transmission drops below this luminance - higher values give speedups in dense volumes at the expense of accuracy ");
 	uiBlockEndAlign(block);
 	
 	yco -= YSPACE;
@@ -4921,6 +4996,9 @@ void texture_panels()
 				texture_panel_pointdensity(tex);
 				texture_panel_pointdensity_modify(tex);
 				break;
+			case TEX_VOXELDATA:
+				texture_panel_voxeldata(tex);
+				break;
 			}
 		}
 	}