Orange; WIP commit for inclusion of "Tangent" vector in rendering.

This first implementation only supports it for Meshes with UV maps, and
only tangents in V direction.

Tangent diffuse:
http://www.blender.org/bf/0001_0080.avi
Tangent spec, diffuse, and bump:
http://www.blender.org/bf/20001_0080.avi

NOTE: since UV coordinates are still very badly subsurfed, this won't work
well for subsurf meshes... on the todo.

On the todo;
- generate tangents for meshes without UV (with some options)
- use tangents from Curve/Surface
- add the Ashkimin shader from tracker

-----

Important bugfix; curves didn't render anymore since yesterday. :)

8 files changed, 235 insertions, 108 deletions

diff --git a/source/blender/blenkernel/BKE_utildefines.h b/source/blender/blenkernel/BKE_utildefines.h
index f0b05802e97..f784973708d 100644
--- a/source/blender/blenkernel/BKE_utildefines.h
+++ b/source/blender/blenkernel/BKE_utildefines.h
@@ -1,5 +1,3 @@
-/* util defines  -- might go away ?*/
-
 /* 
 	$Id$
 
@@ -103,6 +101,7 @@
 
 #define VECADD(v1,v2,v3) 	{*(v1)= *(v2) + *(v3); *(v1+1)= *(v2+1) + *(v3+1); *(v1+2)= *(v2+2) + *(v3+2);}
 #define VECSUB(v1,v2,v3) 	{*(v1)= *(v2) - *(v3); *(v1+1)= *(v2+1) - *(v3+1); *(v1+2)= *(v2+2) - *(v3+2);}
+#define VECADDFAC(v1,v2,v3,fac) {*(v1)= *(v2) + *(v3)*(fac); *(v1+1)= *(v2+1) + *(v3+1)*(fac); *(v1+2)= *(v2+2) + *(v3+2)*(fac);}
 
 #define INPR(v1, v2)		( (v1)[0]*(v2)[0] + (v1)[1]*(v2)[1] + (v1)[2]*(v2)[2] )
 
diff --git a/source/blender/makesdna/DNA_material_types.h b/source/blender/makesdna/DNA_material_types.h
index ff2eb7194eb..9991148ad3d 100644
--- a/source/blender/makesdna/DNA_material_types.h
+++ b/source/blender/makesdna/DNA_material_types.h
@@ -169,6 +169,8 @@ typedef struct Material {
 #define MA_FULL_OSA		0x800000
 #define MA_TANGENT_STR	0x1000000
 #define MA_SHADBUF		0x2000000
+		/* note; we drop MA_TANGENT_STR later to become tangent_u */
+#define MA_TANGENT_V	0x4000000
 
 /* diff_shader */
 #define MA_DIFF_LAMBERT		0
@@ -217,9 +219,8 @@ typedef struct Material {
 #define TEXCO_OSA		512
 #define TEXCO_WINDOW	1024
 #define NEED_UV			2048
-	/* optim = use simpler AA */
-#define TEXCO_OPTIM		4096
-	/* stored in vertex->accum, 1 D */
+#define TEXCO_TANGENT	4096
+	/* still stored in vertex->accum, 1 D */
 #define TEXCO_STRAND	8192
 #define TEXCO_STRESS	16384
 
diff --git a/source/blender/render/intern/source/rendercore.c b/source/blender/render/intern/source/rendercore.c
index 3ca504e2ce4..0d6e141df5f 100644
--- a/source/blender/render/intern/source/rendercore.c
+++ b/source/blender/render/intern/source/rendercore.c
@@ -1636,7 +1636,14 @@ void shade_lamp_loop(ShadeInput *shi, ShadeResult *shr)
 		if(vlr->flag & R_TANGENT) {
 			float cross[3];
 			Crossf(cross, lv, vn);
-			Crossf(vnor, cross, shi->vn);
+			Crossf(vnor, cross, vn);
+			vnor[0]= -vnor[0];vnor[1]= -vnor[1];vnor[2]= -vnor[2];
+			vn= vnor;
+		}
+		else if(ma->mode & MA_TANGENT_V) {
+			float cross[3];
+			Crossf(cross, lv, shi->tang);
+			Crossf(vnor, cross, shi->tang);
 			vnor[0]= -vnor[0];vnor[1]= -vnor[1];vnor[2]= -vnor[2];
 			vn= vnor;
 		}
@@ -1685,7 +1692,9 @@ void shade_lamp_loop(ShadeInput *shi, ShadeResult *shr)
 		}
 		
 		vn= shi->vn;	// bring back original vector, we use special specular shaders for tangent
-		
+		if(ma->mode & MA_TANGENT_V)
+			vn= shi->tang;
+			
 		/* shadow and spec, (lampdist==0 outside spot) */
 		if(lampdist> 0.0) {
 			
@@ -1762,15 +1771,15 @@ void shade_lamp_loop(ShadeInput *shi, ShadeResult *shr)
 					float specfac;
 
 					if(ma->spec_shader==MA_SPEC_PHONG) 
-						specfac= Phong_Spec(vn, lv, view, shi->har, vlr->flag & R_TANGENT);
+						specfac= Phong_Spec(vn, lv, view, shi->har, (vlr->flag & R_TANGENT) || (ma->mode & MA_TANGENT_V));
 					else if(ma->spec_shader==MA_SPEC_COOKTORR) 
-						specfac= CookTorr_Spec(vn, lv, view, shi->har, vlr->flag & R_TANGENT);
+						specfac= CookTorr_Spec(vn, lv, view, shi->har, (vlr->flag & R_TANGENT) || (ma->mode & MA_TANGENT_V));
 					else if(ma->spec_shader==MA_SPEC_BLINN) 
-						specfac= Blinn_Spec(vn, lv, view, ma->refrac, (float)shi->har, vlr->flag & R_TANGENT);
+						specfac= Blinn_Spec(vn, lv, view, ma->refrac, (float)shi->har, (vlr->flag & R_TANGENT) || (ma->mode & MA_TANGENT_V));
 					else if(ma->spec_shader==MA_SPEC_WARDISO)
-						specfac= WardIso_Spec( vn, lv, view, ma->rms, vlr->flag & R_TANGENT);
+						specfac= WardIso_Spec( vn, lv, view, ma->rms, (vlr->flag & R_TANGENT) || (ma->mode & MA_TANGENT_V));
 					else 
-						specfac= Toon_Spec(vn, lv, view, ma->param[2], ma->param[3], vlr->flag & R_TANGENT);
+						specfac= Toon_Spec(vn, lv, view, ma->param[2], ma->param[3], (vlr->flag & R_TANGENT) || (ma->mode & MA_TANGENT_V));
 				
 					/* area lamp correction */
 					if(lar->type==LA_AREA) specfac*= inp;
@@ -1979,9 +1988,25 @@ void shade_input_set_coords(ShadeInput *shi, float u, float v, int i1, int i2, i
 			shi->dyno[2]= dl*n3[2]-shi->dyuv[0]*n1[2]-shi->dyuv[1]*n2[2];
 
 		}
+		
+		if(mode & MA_TANGENT_V) {
+			float *s1, *s2, *s3;
+			
+			s1= RE_vertren_get_tangent(v1, 0);
+			s2= RE_vertren_get_tangent(v2, 0);
+			s3= RE_vertren_get_tangent(v3, 0);
+			if(s1 && s2 && s3) {
+				shi->tang[0]= (l*s3[0] - u*s1[0] - v*s2[0]);
+				shi->tang[1]= (l*s3[1] - u*s1[1] - v*s2[1]);
+				shi->tang[2]= (l*s3[2] - u*s1[2] - v*s2[2]);
+			}
+			else shi->tang[0]= shi->tang[1]= shi->tang[2]= 0.0f;
+		}		
 	}
 	else {
 		VECCOPY(shi->vn, shi->facenor);
+		if(mode & MA_TANGENT_V) 
+			shi->tang[0]= shi->tang[1]= shi->tang[2]= 0.0f;
 	}
 
 	/* texture coordinates. shi->dxuv shi->dyuv have been set */
@@ -2100,20 +2125,6 @@ void shade_input_set_coords(ShadeInput *shi, float u, float v, int i1, int i2, i
 					shi->dyuv[0]= 2.0*(dl*uv3[0]-duv[0]*uv1[0]-duv[1]*uv2[0]);
 					shi->dyuv[1]= 2.0*(dl*uv3[1]-duv[0]*uv1[1]-duv[1]*uv2[1]);
 				}
-#if 0
-				{	/* tangent derived from UV, comes back later! (ton) */
-					//float s1= uv2[0] - uv1[0];
-					//float s2= uv3[0] - uv1[0];
-					float t1= uv2[1] - uv1[1];
-					float t2= uv3[1] - uv1[1];
-					
-					shi->vn[0]= (t2 * (v2->co[0]-v1->co[0]) - t1 * (v3->co[0]-v1->co[0])); 
-					shi->vn[1]= (t2 * (v2->co[1]-v1->co[1]) - t1 * (v3->co[1]-v1->co[1]));
-					shi->vn[2]= (t2 * (v2->co[2]-v1->co[2]) - t1 * (v3->co[2]-v1->co[2]));
-					Normalise(shi->vn);
-					vlr->flag |= R_TANGENT;
-				}					
-#endif
 				if(mode & MA_FACETEXTURE) {
 					if((mode & (MA_VERTEXCOL|MA_VERTEXCOLP))==0) {
 						shi->vcol[0]= 1.0;
@@ -2176,6 +2187,12 @@ void shade_input_set_coords(ShadeInput *shi, float u, float v, int i1, int i2, i
 			}
 			else shi->stress= 0.0f;
 		}
+		if(texco & TEXCO_TANGENT) {
+			if((mode & MA_TANGENT_V)==0) {
+				/* just prevent surprises */
+				shi->tang[0]= shi->tang[1]= shi->tang[2]= 0.0f;
+			}
+		}
 	}
 	else {
 		shi->rad[0]= shi->rad[1]= shi->rad[2]= 0.0;
diff --git a/source/blender/render/intern/source/renderdatabase.c b/source/blender/render/intern/source/renderdatabase.c
index 4c7453bf1b1..d37c73dc932 100644
--- a/source/blender/render/intern/source/renderdatabase.c
+++ b/source/blender/render/intern/source/renderdatabase.c
@@ -160,6 +160,7 @@ float *RE_vertren_get_strand(VertRen *ver, int verify)
 	return strand + (ver->index & 255)*RE_STRAND_ELEMS;
 }
 
+/* needs calloc */
 float *RE_vertren_get_tangent(VertRen *ver, int verify)
 {
 	float *tangent;
@@ -168,7 +169,7 @@ float *RE_vertren_get_tangent(VertRen *ver, int verify)
 	tangent= R.vertnodes[nr].tangent;
 	if(tangent==NULL) {
 		if(verify) 
-			tangent= R.vertnodes[nr].tangent= MEM_mallocN(256*RE_TANGENT_ELEMS*sizeof(float), "tangent table");
+			tangent= R.vertnodes[nr].tangent= MEM_callocN(256*RE_TANGENT_ELEMS*sizeof(float), "tangent table");
 		else
 			return NULL;
 	}
diff --git a/source/blender/render/intern/source/texture.c b/source/blender/render/intern/source/texture.c
index 38936ec89fa..dff275e0a71 100644
--- a/source/blender/render/intern/source/texture.c
+++ b/source/blender/render/intern/source/texture.c
@@ -1444,6 +1444,9 @@ void do_material_tex(ShadeInput *shi)
 			else if(mtex->texco==TEXCO_NORM) {
 				co= shi->orn; dx= shi->dxno; dy= shi->dyno;
 			}
+			else if(mtex->texco==TEXCO_TANGENT) {
+				co= shi->tang; dx= shi->dxno; dy= shi->dyno;
+			}
 			else if(mtex->texco==TEXCO_GLOB) {
 				co= shi->gl; dx= shi->dxco; dy= shi->dyco;
 			}
@@ -1690,14 +1693,28 @@ void do_material_tex(ShadeInput *shi)
 						fact= Tnor*tex->norfac;
 						if(fact>1.0) fact= 1.0; else if(fact<-1.0) fact= -1.0;
 						facm= 1.0- fact;
-						shi->vn[0]= facm*shi->vn[0] + fact*texres.nor[0];
-						shi->vn[1]= facm*shi->vn[1] + fact*texres.nor[1];
-						shi->vn[2]= facm*shi->vn[2] + fact*texres.nor[2];
+						if(shi->mat->mode & MA_TANGENT_V) {
+							shi->tang[0]= facm*shi->tang[0] + fact*texres.nor[0];
+							shi->tang[1]= facm*shi->tang[1] + fact*texres.nor[1];
+							shi->tang[2]= facm*shi->tang[2] + fact*texres.nor[2];
+						}
+						else {
+							shi->vn[0]= facm*shi->vn[0] + fact*texres.nor[0];
+							shi->vn[1]= facm*shi->vn[1] + fact*texres.nor[1];
+							shi->vn[2]= facm*shi->vn[2] + fact*texres.nor[2];
+						}
 					}
 					else {
-						shi->vn[0]+= Tnor*tex->norfac*texres.nor[0];
-						shi->vn[1]+= Tnor*tex->norfac*texres.nor[1];
-						shi->vn[2]+= Tnor*tex->norfac*texres.nor[2];
+						if(shi->mat->mode & MA_TANGENT_V) {
+							shi->tang[0]+= Tnor*tex->norfac*texres.nor[0];
+							shi->tang[1]+= Tnor*tex->norfac*texres.nor[1];
+							shi->tang[2]+= Tnor*tex->norfac*texres.nor[2];
+						}
+						else {
+							shi->vn[0]+= Tnor*tex->norfac*texres.nor[0];
+							shi->vn[1]+= Tnor*tex->norfac*texres.nor[1];
+							shi->vn[2]+= Tnor*tex->norfac*texres.nor[2];
+						}
 					}					
 					Normalise(shi->vn);
 					
diff --git a/source/blender/renderconverter/intern/convertBlenderScene.c b/source/blender/renderconverter/intern/convertBlenderScene.c
index 509e42637c0..3b694813e91 100644
--- a/source/blender/renderconverter/intern/convertBlenderScene.c
+++ b/source/blender/renderconverter/intern/convertBlenderScene.c
@@ -320,6 +320,7 @@ static VertRen *RE_duplicate_vertren(VertRen *ver)
 	int index= v1->index;
 	*v1= *ver;
 	v1->index= index;
+	return v1;
 }
 
 static void split_v_renderfaces(int startvlak, int startvert, int usize, int vsize, int uIndex, int cyclu, int cyclv)
@@ -442,7 +443,67 @@ static void calc_edge_stress(Mesh *me, int startvert, int startvlak)
 	MEM_freeN(accum);
 }
 
-static void calc_vertexnormals(int startvert, int startvlak)
+static void calc_tangent_vector(VlakRen *vlr, float fac1, float fac2, float fac3, float fac4)
+{
+	TFace *tface= vlr->tface;
+	
+	if(tface) {
+		VertRen *v1=vlr->v1, *v2=vlr->v2, *v3=vlr->v3, *v4=vlr->v4;
+		float *uv1= tface->uv[0], *uv2= tface->uv[1], *uv3= tface->uv[2], *uv4= tface->uv[3];
+		float tang[3], *tav;
+		float s1, s2, t1, t2, det;
+		
+		/* we calculate quads as two triangles, so weight for diagonal gets halved */
+		if(v4) {
+			fac1*= 0.5f;
+			fac3*= 0.5f;
+		}
+		
+		/* first tria, we use the V now */
+		s1= uv2[0] - uv1[0];
+		s2= uv3[0] - uv1[0];
+		t1= uv2[1] - uv1[1];
+		t2= uv3[1] - uv1[1];
+		det= 1.0f / (s1 * t2 - s2 * t1);
+		
+		/* normals in render are inversed... */
+		tang[0]= (t2 * (v1->co[0]-v2->co[0]) - t1 * (v1->co[0]-v3->co[0])); 
+		tang[1]= (t2 * (v1->co[1]-v2->co[1]) - t1 * (v1->co[1]-v3->co[1]));
+		tang[2]= (t2 * (v1->co[2]-v2->co[2]) - t1 * (v1->co[2]-v3->co[2]));
+		
+		tav= RE_vertren_get_tangent(v1, 1);
+		VECADDFAC(tav, tav, tang, fac1);
+		tav= RE_vertren_get_tangent(v2, 1);
+		VECADDFAC(tav, tav, tang, fac2);
+		tav= RE_vertren_get_tangent(v3, 1);
+		VECADDFAC(tav, tav, tang, fac3);
+		
+		if(v4) {
+			/* 2nd tria, we use the V now */
+			s1= uv3[0] - uv1[0];
+			s2= uv4[0] - uv1[0];
+			t1= uv3[1] - uv1[1];
+			t2= uv4[1] - uv1[1];
+			det= 1.0f / (s1 * t2 - s2 * t1);
+			
+			/* normals in render are inversed... */
+			tang[0]= (t2 * (v1->co[0]-v3->co[0]) - t1 * (v1->co[0]-v4->co[0])); 
+			tang[1]= (t2 * (v1->co[1]-v3->co[1]) - t1 * (v1->co[1]-v4->co[1]));
+			tang[2]= (t2 * (v1->co[2]-v3->co[2]) - t1 * (v1->co[2]-v4->co[2]));
+			
+			Normalise(tang);
+			
+			tav= RE_vertren_get_tangent(v1, 1);
+			VECADDFAC(tav, tav, tang, fac1);
+			tav= RE_vertren_get_tangent(v3, 1);
+			VECADDFAC(tav, tav, tang, fac3);
+			tav= RE_vertren_get_tangent(v4, 1);
+			VECADDFAC(tav, tav, tang, fac4);
+		}
+	}	
+}
+
+static void calc_vertexnormals(int startvert, int startvlak, int do_tangent)
 {
 	int a;
 
@@ -452,7 +513,8 @@ static void calc_vertexnormals(int startvert, int startvlak)
 		ver->n[0]=ver->n[1]=ver->n[2]= 0.0;
 	}
 
-		/* calculate cos of angles and point-masses */
+		/* calculate cos of angles and point-masses, use as weight factor to
+		   add face normal to vertex */
 	for(a=startvlak; a<R.totvlak; a++) {
 		VlakRen *vlr= RE_findOrAddVlak(a);
 		if(vlr->flag & ME_SMOOTH) {
@@ -461,13 +523,13 @@ static void calc_vertexnormals(int startvert, int startvlak)
 			VertRen *adrve3= vlr->v3;
 			VertRen *adrve4= vlr->v4;
 			float n1[3], n2[3], n3[3], n4[3];
-			float fac1, fac2, fac3, fac4;
+			float fac1, fac2, fac3, fac4=0.0f;
 
 			VecSubf(n1, adrve2->co, adrve1->co);
 			Normalise(n1);
 			VecSubf(n2, adrve3->co, adrve2->co);
 			Normalise(n2);
-			if(adrve4==0) {
+			if(adrve4==NULL) {
 				VecSubf(n3, adrve1->co, adrve3->co);
 				Normalise(n3);
 
@@ -512,6 +574,9 @@ static void calc_vertexnormals(int startvert, int startvlak)
 			adrve3->n[0] +=fac3*vlr->n[0];
 			adrve3->n[1] +=fac3*vlr->n[1];
 			adrve3->n[2] +=fac3*vlr->n[2];
+			
+			if(do_tangent)
+				calc_tangent_vector(vlr, fac1, fac2, fac3, fac4);
 		}
 	}
 
@@ -536,6 +601,10 @@ static void calc_vertexnormals(int startvert, int startvlak)
 	for(a=startvert; a<R.totvert; a++) {
 		VertRen *ver= RE_findOrAddVert(a);
 		Normalise(ver->n);
+		if(do_tangent) {
+			float *tav= RE_vertren_get_tangent(ver, 0);
+			if(tav) Normalise(tav);
+		}
 	}
 
 		/* vertex normal (puno) switch flags for during render */
@@ -1192,7 +1261,7 @@ static void render_static_particle_system(Object *ob, PartEff *paf)
 	}
 
 	if((ma->mode & MA_TANGENT_STR)==0)
-		calc_vertexnormals(totverto, totvlako);
+		calc_vertexnormals(totverto, totvlako, 0);
 }
 
 
@@ -1393,7 +1462,7 @@ static void init_render_mesh(Object *ob)
 	unsigned int *vertcol;
 	float xn, yn, zn,  imat[3][3], mat[4][4];  //nor[3],
 	float *orco=0;
-	int a, a1, ok, need_orco=0, need_stress=0, totvlako, totverto, vertofs;
+	int a, a1, ok, need_orco=0, need_stress=0, need_tangent=0, totvlako, totverto, vertofs;
 	int end, do_autosmooth=0, totvert = 0, dm_needsfree;
 	
 	me= ob->data;
@@ -1425,6 +1494,8 @@ static void init_render_mesh(Object *ob)
 				need_orco= 1;
 			if(ma->texco & TEXCO_STRESS)
 				need_stress= 1;
+			if(ma->mode & MA_TANGENT_V)
+				need_tangent= 1;
 		}
 	}
 	
@@ -1632,7 +1703,7 @@ static void init_render_mesh(Object *ob)
 	}
 	
 	if (test_for_displace( ob ) ) {
-		calc_vertexnormals(totverto, totvlako);
+		calc_vertexnormals(totverto, totvlako, 0);
 		do_displacement(ob, totvlako, R.totvlak-totvlako, totverto, R.totvert-totverto);
 	}
 
@@ -1640,7 +1711,7 @@ static void init_render_mesh(Object *ob)
 		autosmooth(totverto, totvlako, me->smoothresh);
 	}
 
-	calc_vertexnormals(totverto, totvlako);
+	calc_vertexnormals(totverto, totvlako, need_tangent);
 
 	if(need_stress)
 		calc_edge_stress(me, totverto, totvlako);
@@ -2267,7 +2338,7 @@ static void init_render_curve(Object *ob)
 				ver= RE_findOrAddVert(a);
 				len= Normalise(ver->n);
 				if(len==0.0) ver->flag= 1;	/* flag use, its only used in zbuf now  */
-				else ver->flag= 1;
+				else ver->flag= 0;
 			}
 			for(a= startvlak; a<R.totvlak; a++) {
 				vlr= RE_findOrAddVlak(a);
@@ -3066,6 +3137,6 @@ static void do_displacement(Object *ob, int startface, int numface, int startver
 	}
 	
 	/* Recalc vertex normals */
-	calc_vertexnormals(startvert, startface);
+	calc_vertexnormals(startvert, startface, 0);
 }
 
diff --git a/source/blender/src/buttons_shading.c b/source/blender/src/buttons_shading.c
index b697d4cab34..27504e1d2e0 100644
--- a/source/blender/src/buttons_shading.c
+++ b/source/blender/src/buttons_shading.c
@@ -2856,27 +2856,29 @@ static void material_panel_map_input(Object *ob, Material *ma)
 	
 	/* TEXCO */
 	uiBlockBeginAlign(block);
-	uiDefButS(block, ROW, B_MATPRV, "UV",			630,166,40,18, &(mtex->texco), 4.0, (float)TEXCO_UV, 0, 0, "Uses UV coordinates for texture coordinates");
-	uiDefButS(block, ROW, B_MATPRV, "Glob",			670,166,45,18, &(mtex->texco), 4.0, (float)TEXCO_GLOB, 0, 0, "Uses global coordinates for the texture coordinates");
-	uiDefButS(block, ROW, B_MATPRV, "Object",		715,166,75,18, &(mtex->texco), 4.0, (float)TEXCO_OBJECT, 0, 0, "Uses linked object's coordinates for texture coordinates");
-	uiDefIDPoinBut(block, test_obpoin_but, ID_OB, B_MATPRV, "",790,166,118,18, &(mtex->object), "");
+	uiDefButS(block, ROW, B_MATPRV, "Glob",			630,180,45,18, &(mtex->texco), 4.0, (float)TEXCO_GLOB, 0, 0, "Uses global coordinates for the texture coordinates");
+	uiDefButS(block, ROW, B_MATPRV, "Object",		675,180,75,18, &(mtex->texco), 4.0, (float)TEXCO_OBJECT, 0, 0, "Uses linked object's coordinates for texture coordinates");
+	uiDefIDPoinBut(block, test_obpoin_but, ID_OB, B_MATPRV, "",750,180,158,18, &(mtex->object), "");
 	
-	uiDefButS(block, ROW, B_MATPRV, "Orco",			630,146,45,18, &(mtex->texco), 4.0, (float)TEXCO_ORCO, 0, 0, "Uses the original undeformed coordinates of the object");
-	uiDefButS(block, ROW, B_MATPRV, "Stress",		675,146,50,18, &(mtex->texco), 4.0, (float)TEXCO_STRESS, 0, 0, "Uses the difference of edge lengths compared to original coordinates of the mesh");
+	uiDefButS(block, ROW, B_MATPRV, "UV",			630,160,40,18, &(mtex->texco), 4.0, (float)TEXCO_UV, 0, 0, "Uses UV coordinates for texture coordinates");
+	uiDefButS(block, ROW, B_MATPRV, "Orco",			670,160,55,18, &(mtex->texco), 4.0, (float)TEXCO_ORCO, 0, 0, "Uses the original undeformed coordinates of the object");
 	if( give_parteff(ob) )
-		uiDefButS(block, ROW, B_MATPRV, "Strand",	725,146,50,18, &(mtex->texco), 4.0, (float)TEXCO_STRAND, 0, 0, "Uses normalized strand texture coordinate (1D)");
+		uiDefButS(block, ROW, B_MATPRV, "Strand",	725,160,50,18, &(mtex->texco), 4.0, (float)TEXCO_STRAND, 0, 0, "Uses normalized strand texture coordinate (1D)");
 	else
-		uiDefButS(block, ROW, B_MATPRV, "Stick",		725,146,50,18, &(mtex->texco), 4.0, (float)TEXCO_STICKY, 0, 0, "Uses mesh's sticky coordinates for the texture coordinates");
-	uiDefButS(block, ROW, B_MATPRV, "Win",			775,146,45,18, &(mtex->texco), 4.0, (float)TEXCO_WINDOW, 0, 0, "Uses screen coordinates as texture coordinates");
-	uiDefButS(block, ROW, B_MATPRV, "Nor",			820,146,44,18, &(mtex->texco), 4.0, (float)TEXCO_NORM, 0, 0, "Uses normal vector as texture coordinates");
-	uiDefButS(block, ROW, B_MATPRV, "Refl",			864,146,44,18, &(mtex->texco), 4.0, (float)TEXCO_REFL, 0, 0, "Uses reflection vector as texture coordinates");
+		uiDefButS(block, ROW, B_MATPRV, "Stick",	725,160,50,18, &(mtex->texco), 4.0, (float)TEXCO_STICKY, 0, 0, "Uses mesh's sticky coordinates for the texture coordinates");
+	uiDefButS(block, ROW, B_MATPRV, "Win",			775,160,45,18, &(mtex->texco), 4.0, (float)TEXCO_WINDOW, 0, 0, "Uses screen coordinates as texture coordinates");
+	uiDefButS(block, ROW, B_MATPRV, "Nor",			820,160,44,18, &(mtex->texco), 4.0, (float)TEXCO_NORM, 0, 0, "Uses normal vector as texture coordinates");
+	uiDefButS(block, ROW, B_MATPRV, "Refl",			864,160,44,18, &(mtex->texco), 4.0, (float)TEXCO_REFL, 0, 0, "Uses reflection vector as texture coordinates");
+	
+	uiDefButS(block, ROW, B_MATPRV, "Stress",		630,140,70,18, &(mtex->texco), 4.0, (float)TEXCO_STRESS, 0, 0, "Uses the difference of edge lengths compared to original coordinates of the mesh");
+	uiDefButS(block, ROW, B_MATPRV, "Tangent",		700,140,70,18, &(mtex->texco), 4.0, (float)TEXCO_TANGENT, 0, 0, "Uses te optional tangent vector as texture coordinates");
 
 	/* COORDS */
 	uiBlockBeginAlign(block);
-	uiDefButC(block, ROW, B_MATPRV, "Flat",			630,114,48,18, &(mtex->mapping), 5.0, (float)MTEX_FLAT, 0, 0, "Maps X and Y coordinates directly");
-	uiDefButC(block, ROW, B_MATPRV, "Cube",			681,114,50,18, &(mtex->mapping), 5.0, (float)MTEX_CUBE, 0, 0, "Maps using the normal vector");
-	uiDefButC(block, ROW, B_MATPRV, "Tube",			630,94,48,18, &(mtex->mapping), 5.0, (float)MTEX_TUBE, 0, 0, "Maps with Z as central axis (tube-like)");
-	uiDefButC(block, ROW, B_MATPRV, "Sphe",			681,94,50,18, &(mtex->mapping), 5.0, (float)MTEX_SPHERE, 0, 0, "Maps with Z as central axis (sphere-like)");
+	uiDefButC(block, ROW, B_MATPRV, "Flat",			630,115,48,19, &(mtex->mapping), 5.0, (float)MTEX_FLAT, 0, 0, "Maps X and Y coordinates directly");
+	uiDefButC(block, ROW, B_MATPRV, "Cube",			681,115,50,19, &(mtex->mapping), 5.0, (float)MTEX_CUBE, 0, 0, "Maps using the normal vector");
+	uiDefButC(block, ROW, B_MATPRV, "Tube",			630,95,48,19, &(mtex->mapping), 5.0, (float)MTEX_TUBE, 0, 0, "Maps with Z as central axis (tube-like)");
+	uiDefButC(block, ROW, B_MATPRV, "Sphe",			681,95,50,19, &(mtex->mapping), 5.0, (float)MTEX_SPHERE, 0, 0, "Maps with Z as central axis (sphere-like)");
 
 	uiBlockBeginAlign(block);
 	for(b=0; b<3; b++) {
@@ -2892,13 +2894,13 @@ static void material_panel_map_input(Object *ob, Material *ma)
 	}
 	
 	uiBlockBeginAlign(block);
-	uiDefButF(block, NUM, B_MATPRV, "ofsX",		778,114,130,18, mtex->ofs, -10.0, 10.0, 10, 0, "Fine tunes texture mapping X coordinate");
-	uiDefButF(block, NUM, B_MATPRV, "ofsY",		778,94,130,18, mtex->ofs+1, -10.0, 10.0, 10, 0, "Fine tunes texture mapping Y coordinate");
-	uiDefButF(block, NUM, B_MATPRV, "ofsZ",		778,74,130,18, mtex->ofs+2, -10.0, 10.0, 10, 0, "Fine tunes texture mapping Z coordinate");
+	uiDefButF(block, NUM, B_MATPRV, "ofsX",		778,115,130,19, mtex->ofs, -10.0, 10.0, 10, 0, "Fine tunes texture mapping X coordinate");
+	uiDefButF(block, NUM, B_MATPRV, "ofsY",		778,95,130,19, mtex->ofs+1, -10.0, 10.0, 10, 0, "Fine tunes texture mapping Y coordinate");
+	uiDefButF(block, NUM, B_MATPRV, "ofsZ",		778,75,130,19, mtex->ofs+2, -10.0, 10.0, 10, 0, "Fine tunes texture mapping Z coordinate");
 	uiBlockBeginAlign(block);
-	uiDefButF(block, NUM, B_MATPRV, "sizeX",	778,50,130,18, mtex->size, -100.0, 100.0, 10, 0, "Sets scaling for the texture's X size");
-	uiDefButF(block, NUM, B_MATPRV, "sizeY",	778,30,130,18, mtex->size+1, -100.0, 100.0, 10, 0, "Sets scaling for the texture's Y size");
-	uiDefButF(block, NUM, B_MATPRV, "sizeZ",	778,10,130,18, mtex->size+2, -100.0, 100.0, 10, 0, "Sets scaling for the texture's Z size");
+	uiDefButF(block, NUM, B_MATPRV, "sizeX",	778,50,130,19, mtex->size, -100.0, 100.0, 10, 0, "Sets scaling for the texture's X size");
+	uiDefButF(block, NUM, B_MATPRV, "sizeY",	778,30,130,19, mtex->size+1, -100.0, 100.0, 10, 0, "Sets scaling for the texture's Y size");
+	uiDefButF(block, NUM, B_MATPRV, "sizeZ",	778,10,130,19, mtex->size+2, -100.0, 100.0, 10, 0, "Sets scaling for the texture's Z size");
 	uiBlockEndAlign(block);
 
 }
@@ -3173,18 +3175,19 @@ static void material_panel_shading(Material *ma)
 
 		uiBlockSetCol(block, TH_BUT_SETTING1);
 		uiBlockBeginAlign(block);
-		uiDefButBitI(block, TOG, MA_TRACEBLE, 0,"Traceable",		245,160,65,18, &(ma->mode), 0, 0, 0, 0, "Makes material to being detected by ray tracing");
-		uiDefButBitI(block, TOG, MA_SHADBUF, 0,	"Shadbuf",			245,142,65,18, &(ma->mode), 0, 0, 0, 0, "Makes material to cast shadows with shadow buffers");
+		uiDefButBitI(block, TOG, MA_TRACEBLE, B_NOP,"Traceable",		245,160,65,18, &(ma->mode), 0, 0, 0, 0, "Makes material to being detected by ray tracing");
+		uiDefButBitI(block, TOG, MA_SHADBUF, B_NOP,	"Shadbuf",			245,142,65,18, &(ma->mode), 0, 0, 0, 0, "Makes material to cast shadows with shadow buffers");
 
 		uiBlockBeginAlign(block);
-		uiDefButBitI(block, TOG, MA_SHADOW, 0,	"Shadow",			245,120,65,19, &(ma->mode), 0, 0, 0, 0, "Makes material receive shadows");
-		uiDefButBitI(block, TOG, MA_SHADOW_TRA, 0, "TraShadow",		245,100,65,19, &(ma->mode), 0, 0, 0, 0, "Recieves transparent shadows based at material color and alpha");
-		uiDefButBitI(block, TOG, MA_RAYBIAS, 0, "Bias",				245,80,65,19, &(ma->mode), 0, 0, 0, 0, "Prevents ray traced shadow errors with phong interpolated normals (terminator problem)");
+		uiDefButBitI(block, TOG, MA_SHADOW, B_NOP,	"Shadow",			245,120,65,19, &(ma->mode), 0, 0, 0, 0, "Makes material receive shadows");
+		uiDefButBitI(block, TOG, MA_SHADOW_TRA, B_NOP, "TraShadow",		245,100,65,19, &(ma->mode), 0, 0, 0, 0, "Recieves transparent shadows based at material color and alpha");
+		uiDefButBitI(block, TOG, MA_RAYBIAS, B_NOP, "Bias",				245,80,65,19, &(ma->mode), 0, 0, 0, 0, "Prevents ray traced shadow errors with phong interpolated normals (terminator problem)");
 		uiBlockEndAlign(block);
 
 		uiDefIDPoinBut(block, test_grouppoin_but, ID_GR, B_NOP, "GR:", 9, 55, 150, 19, &ma->group, "Limit Lighting to Lamps in this Group"); 
-
-		uiDefButBitI(block, TOG, MA_RADIO, 0,	"Radio",			245,55,65,19, &(ma->mode), 0, 0, 0, 0, "Enables material for radiosity rendering");
+		
+		uiDefButBitI(block, TOG, MA_TANGENT_V, B_MATPRV, "Tangent V",		170,55,65,19, &(ma->mode), 0, 0, 0, 0, "Use the tangent vector in V direction for shading");
+		uiDefButBitI(block, TOG, MA_RADIO, B_NOP,	"Radio",			245,55,65,19, &(ma->mode), 0, 0, 0, 0, "Enables material for radiosity rendering");
 
 	}
 }
diff --git a/source/blender/src/previewrender.c b/source/blender/src/previewrender.c
index 3667b170270..e53e7a30097 100644
--- a/source/blender/src/previewrender.c
+++ b/source/blender/src/previewrender.c
@@ -734,7 +734,7 @@ static void shade_lamp_loop_preview(ShadeInput *shi, ShadeResult *shr, int pr_la
 	extern float fresnel_fac(float *view, float *vn, float ior, float fac);
 	Material *mat= shi->mat;
 	float inp, is, inprspec=0;
-	float lv[3], *la;
+	float lv[3], *la, *vn, vnor[3];
 	int a;
 	
 	// copy all relevant material vars, note, keep this synced with render_types.h
@@ -779,47 +779,57 @@ static void shade_lamp_loop_preview(ShadeInput *shi, ShadeResult *shr, int pr_la
 			lv[2]= shi->co[2]-la[2];
 			Normalise(lv);
 			
-			is= shi->vn[0]*lv[0]+shi->vn[1]*lv[1]+shi->vn[2]*lv[2];
-			if(is<0.0f) is= 0.0f;
-			
 			if(shi->spec>0.0f)  {
+				/* specular shaders */
+				float specfac;
 				
-				if(is>0.0f) {
-					/* specular shaders */
-					float specfac;
-					
-					if(mat->spec_shader==MA_SPEC_PHONG) 
-						specfac= Phong_Spec(shi->vn, lv, shi->view, shi->har, 0);
-					else if(mat->spec_shader==MA_SPEC_COOKTORR) 
-						specfac= CookTorr_Spec(shi->vn, lv, shi->view, shi->har, 0);
-					else if(mat->spec_shader==MA_SPEC_BLINN) 
-						specfac= Blinn_Spec(shi->vn, lv, shi->view, mat->refrac, (float)shi->har, 0);
-					else if(mat->spec_shader==MA_SPEC_WARDISO)
-						specfac= WardIso_Spec(shi->vn, lv, shi->view, mat->rms, 0);
-					else 
-						specfac= Toon_Spec(shi->vn, lv, shi->view, mat->param[2], mat->param[3], 0);
-					
-					inprspec= specfac*shi->spec;
-					
-					if(mat->mode & MA_RAMP_SPEC) {
-						float spec[3];
-						do_specular_ramp(shi, specfac, inprspec, spec);
-						shr->spec[0]+= inprspec*spec[0];
-						shr->spec[1]+= inprspec*spec[1];
-						shr->spec[2]+= inprspec*spec[2];
-					}
-					else {	
-						shr->spec[0]+= inprspec*shi->specr;
-						shr->spec[1]+= inprspec*shi->specg;
-						shr->spec[2]+= inprspec*shi->specb;
-					}
+				if(mat->mode & MA_TANGENT_V) vn= shi->tang;
+				else vn= shi->vn;
+				
+				if(mat->spec_shader==MA_SPEC_PHONG) 
+					specfac= Phong_Spec(vn, lv, shi->view, shi->har, mat->mode & MA_TANGENT_V);
+				else if(mat->spec_shader==MA_SPEC_COOKTORR) 
+					specfac= CookTorr_Spec(vn, lv, shi->view, shi->har, mat->mode & MA_TANGENT_V);
+				else if(mat->spec_shader==MA_SPEC_BLINN) 
+					specfac= Blinn_Spec(vn, lv, shi->view, mat->refrac, (float)shi->har, mat->mode & MA_TANGENT_V);
+				else if(mat->spec_shader==MA_SPEC_WARDISO)
+					specfac= WardIso_Spec(vn, lv, shi->view, mat->rms, mat->mode & MA_TANGENT_V);
+				else 
+					specfac= Toon_Spec(vn, lv, shi->view, mat->param[2], mat->param[3], mat->mode & MA_TANGENT_V);
+				
+				inprspec= specfac*shi->spec;
+				
+				if(mat->mode & MA_RAMP_SPEC) {
+					float spec[3];
+					do_specular_ramp(shi, specfac, inprspec, spec);
+					shr->spec[0]+= inprspec*spec[0];
+					shr->spec[1]+= inprspec*spec[1];
+					shr->spec[2]+= inprspec*spec[2];
+				}
+				else {	
+					shr->spec[0]+= inprspec*shi->specr;
+					shr->spec[1]+= inprspec*shi->specg;
+					shr->spec[2]+= inprspec*shi->specb;
 				}
 			}
+			
+			if(mat->mode & MA_TANGENT_V) {
+				float cross[3];
+				Crossf(cross, lv, shi->tang);
+				Crossf(vnor, cross, shi->tang);
+				vnor[0]= -vnor[0];vnor[1]= -vnor[1];vnor[2]= -vnor[2];
+				vn= vnor;
+			}
+			else vn= shi->vn;
+			
+			is= vn[0]*lv[0]+vn[1]*lv[1]+vn[2]*lv[2];
+			if(is<0.0f) is= 0.0f;
+			
 			/* diffuse shaders */
-			if(mat->diff_shader==MA_DIFF_ORENNAYAR) is= OrenNayar_Diff(shi->vn, lv, shi->view, mat->roughness);
-			else if(mat->diff_shader==MA_DIFF_TOON) is= Toon_Diff(shi->vn, lv, shi->view, mat->param[0], mat->param[1]);
-			else if(mat->diff_shader==MA_DIFF_MINNAERT) is= Minnaert_Diff(is, shi->vn, shi->view, mat->darkness);
-			else if(mat->diff_shader==MA_DIFF_FRESNEL) is= Fresnel_Diff(shi->vn, lv, shi->view, mat->param[0], mat->param[1]);
+			if(mat->diff_shader==MA_DIFF_ORENNAYAR) is= OrenNayar_Diff(vn, lv, shi->view, mat->roughness);
+			else if(mat->diff_shader==MA_DIFF_TOON) is= Toon_Diff(vn, lv, shi->view, mat->param[0], mat->param[1]);
+			else if(mat->diff_shader==MA_DIFF_MINNAERT) is= Minnaert_Diff(is, vn, shi->view, mat->darkness);
+			else if(mat->diff_shader==MA_DIFF_FRESNEL) is= Fresnel_Diff(vn, lv, shi->view, mat->param[0], mat->param[1]);
 			// else Lambert
 			
 			inp= (shi->refl*is + shi->emit);
@@ -1287,6 +1297,14 @@ void BIF_previewrender(SpaceButs *sbuts)
 							vec[1]= shi.vn[2];
 							vec[2]= -shi.vn[1];
 							
+							if(mat->mode & MA_TANGENT_V) {
+								float tmp[3];
+								tmp[0]=tmp[2]= 0.0f;
+								tmp[1]= 1.0f;
+								Crossf(shi.tang, tmp, shi.vn);
+								Normalise(shi.tang);
+							}
+							
 							shade_preview_pixel(&shi, vec, x, y, (char *)rect, 1);
 						}
 						else {