diff --git a/all_includes.hh b/all_includes.hh
index d3e3e7b..42d55bc 100644
--- a/all_includes.hh
+++ b/all_includes.hh
@@ -20,9 +20,9 @@ class Chose;
 #include <GL/glu.h>
 #include <GL/gl.h>
 
-#include "geometry/angle.hh"
 #include "geometry/directions.hh"
 #include "geometry/vertex.hh"
+#include "geometry/angle.hh"
 #include "geometry/segment.hh"
 #include "geometry/triangle.hh"
 #include "geometry/quad.hh"
@@ -38,6 +38,7 @@ class Chose;
 #include "rules/chose.hh"
 #include "rules/architecture/couleursDimensions.hh"
 
+#include "rules/architecture/arbre.hh"
 #include "rules/architecture/arche.hh"
 #include "rules/architecture/batiment.hh"
 #include "rules/architecture/quartier.hh"
diff --git a/geometry/angle.cpp b/geometry/angle.cpp
index 41b1ed7..55f2f3c 100644
--- a/geometry/angle.cpp
+++ b/geometry/angle.cpp
@@ -2,3 +2,19 @@
 
 float Angle::r2d(float rad) { return rad / Pi * 180; }
 float Angle::d2r(float deg) { return deg / 180 * Pi; }
+
+Angle3D::Angle3D() : h(Vertex(1,0,0)), l(Vertex(0,1,0)), u(Vertex(0,0,1)) {}
+Angle3D::Angle3D(Vertex _h, Vertex _l, Vertex _u) : h(_h), l(_l), u(_u) {}
+
+// Formules : http://www.nbb.cornell.edu/neurobio/land/OldStudentProjects/cs490-94to95/hwchen/
+Angle3D Angle3D::rotateH(float angle) const {
+	return Angle3D(h, l*std::cos(angle) + u*std::sin(angle), l*-std::sin(angle) + u*std::cos(angle));
+}
+
+Angle3D Angle3D::rotateL(float angle) const {
+	return Angle3D(h*std::cos(angle) + u*std::sin(angle), l, h*-std::sin(angle) + u*std::cos(angle));
+}
+
+Angle3D Angle3D::rotateU(float angle) const {
+	return Angle3D(h*std::cos(angle) + l*-std::sin(angle), h*std::sin(angle) + l*std::cos(angle), u);
+}
diff --git a/geometry/angle.hh b/geometry/angle.hh
index 19f312c..6da7635 100644
--- a/geometry/angle.hh
+++ b/geometry/angle.hh
@@ -1,6 +1,8 @@
 #ifndef _GEOMETRY_ANGLE_HH_
 #define _GEOMETRY_ANGLE_HH_
 
+#include "all_includes.hh"
+
 namespace Angle {
 	const double dPi = 3.141592653589793238462643383279;
 	const float Pi = (float)(dPi);
@@ -8,4 +10,16 @@ namespace Angle {
 	float d2r(float deg);
 }
 
+class Angle3D {
+public:
+	Vertex h;
+	Vertex l;
+	Vertex u;
+	Angle3D();
+	Angle3D(Vertex _h, Vertex _l, Vertex _u);
+	Angle3D rotateH(float angle) const;
+	Angle3D rotateL(float angle) const;
+	Angle3D rotateU(float angle) const;
+};
+
 #endif
diff --git a/geometry/quad.cpp b/geometry/quad.cpp
index 39088f5..6aed4b0 100644
--- a/geometry/quad.cpp
+++ b/geometry/quad.cpp
@@ -243,3 +243,11 @@ Quad Quad::offsetNormal(float offset) const {
 Vertex Quad::normal() const {
 	return Triangle(c[NE], c[SE], c[SW]).normal();
 }
+
+Vertex Quad::normalizedNormal() const {
+	return Triangle(c[NE], c[SE], c[SW]).normalizedNormal();
+}
+
+Vertex Quad::moyenne() const {
+	return ((c[NE] + c[SE] + c[SW] + c[NW]) / 4.f);
+}
diff --git a/geometry/quad.hh b/geometry/quad.hh
index 94b5993..6c31e29 100644
--- a/geometry/quad.hh
+++ b/geometry/quad.hh
@@ -51,6 +51,8 @@ class Quad {
 	Quad insetProportionnal(float prop);
 	Quad offsetNormal(float offset) const;
 	Vertex normal() const;
+	Vertex normalizedNormal() const;
+	Vertex moyenne() const;
 };
 
 
diff --git a/geometry/vertex.cpp b/geometry/vertex.cpp
index e46c526..93ae5f1 100644
--- a/geometry/vertex.cpp
+++ b/geometry/vertex.cpp
@@ -21,6 +21,10 @@ Vertex Vertex::setNorm(float n) const {
 	return (*this * n / norm());
 }
 
+Vertex Vertex::normalize() const {
+	return (*this / norm());
+}
+
 float Vertex::cosAngle(Vertex v) const {
 	// http://www.developpez.net/forums/d202580/applications/developpement-2d-3d-jeux/contribuez/faq-mat-quat-ajout-calculs-vectoriels/
 	return ((this->x*v.x + this->y*v.y + this->z*v.z) / (norm()*v.norm()));
diff --git a/geometry/vertex.hh b/geometry/vertex.hh
index 8bc2532..39ffb51 100644
--- a/geometry/vertex.hh
+++ b/geometry/vertex.hh
@@ -15,6 +15,7 @@ class Vertex {
 	float norm() const;
 	Vertex projectOn(Vertex v) const;
 	Vertex setNorm(float n) const;
+	Vertex normalize() const;
 	float cosAngle(Vertex v) const; // cosinus de l'angle entre this et v.
 	float angle(Vertex v) const; // Angle entre this et v.
 	static Vertex fromSpherical(float r, float xAngle, float yAngle);
@@ -24,7 +25,7 @@ class Vertex {
 	friend Vertex operator+(const Vertex& u, const Vertex& v);
 	friend Vertex operator-(const Vertex& u, const Vertex& v);
 	friend Vertex operator-(const Vertex& v);
-	friend Vertex operator*(const Vertex& v, const float n);
+	friend Vertex operator*(const Vertex& v, const float n); // Cross product
 	friend Vertex operator*(const Vertex& u, const Vertex& v);
 	friend Vertex operator/(const Vertex& v, const float f);
 };
diff --git a/rules/architecture/arbre.cpp b/rules/architecture/arbre.cpp
new file mode 100644
index 0000000..a1e9cc5
--- /dev/null
+++ b/rules/architecture/arbre.cpp
@@ -0,0 +1,97 @@
+#include "all_includes.hh"
+
+Arbre::Arbre(Vertex _start, Triangle plane) : start(_start), type(ARBRE) {
+	addEntropy(start);
+	addEntropy(plane);
+
+	Vertex h = plane.normalizedNormal();
+	Vertex l = (plane[TOP] - plane[LEFT]).normalize();
+	Vertex u = h * l;
+
+	rotation = Angle3D(h, l, u);
+	rotation = rotation.rotateH(floatInRange(seed, -3, 0, 2*Angle::Pi));
+	rotation = rotation.rotateU(floatInRange(seed, -4, Angle::d2r(-10), Angle::d2r(10)));
+	length = floatInRange(seed, -5, 3*100, 4*100);
+}
+
+Arbre::Arbre(Vertex _start, Angle3D _rotation, float _length, Type _type) : start(_start), rotation(_rotation), length(_length), type(_type) {
+	addEntropy(start, rotation.h, rotation.l, rotation.u);
+	addEntropy(length);
+	addEntropy((int)(type));
+}
+
+bool Arbre::split() {
+	if (type == ARBRE && length > floatInRange(seed, -1, 10, 20)) {
+		int nbBranches = 2 + (hash2(seed, -2) % 3);
+		for (int i = 0; i < nbBranches; i++) {
+			Vertex bStart = end(floatInRange(seed, 4*i, 0.7f, 0.9f));
+			Angle3D rot = rotation;
+			rot = rot.rotateH(Angle::d2r(floatInRange(seed, 4*i+1, 25.f, 37.f) + i*(360.f / (float)nbBranches)));
+			rot = rot.rotateU(Angle::d2r(floatInRange(seed, 4*i+2, 35.f, 55.f)));
+			float len = length * floatInRange(seed, 4*i+3, tauxMax()*2.f/3.f, tauxMax());
+			addChild(new Arbre(bStart, rot, len, ARBRE));
+		}
+		addChild(new Arbre(start, rotation, length, TRONC));
+	}
+	return true;
+}
+
+void Arbre::triangulation() {
+	if (type == ARBRE || type == TRONC) tronc();
+	if (type == ARBRE) feuille();
+}
+
+void Arbre::getBoundingBoxPoints() {
+	// TODO
+	Vertex u = rotation.u * limitLength() / 2.f;
+	Vertex l = rotation.l * limitLength() / 2.f;
+	Quad c(start +u +l, start -u +l, start -u -l, start +u -l);
+	addBBPoints(c, length + limitLength());
+}
+
+float Arbre::LODFactor() {
+	return 4.f;
+}
+
+Vertex Arbre::end(float position) const {
+	return (start + rotation.h * length * position);
+}
+
+float Arbre::tauxMax() {
+	return 0.6f;
+}
+const float Arbre::limitLengthFactor = calcLimitLengthFactor();
+float Arbre::calcLimitLengthFactor() {
+	float limit = 0;
+	for (float i = 1; i > 0.001; i = i * tauxMax())
+		limit += i;
+	return limit - 1;
+}
+
+float Arbre::limitLength() const {
+	return length * limitLengthFactor;
+}
+
+float Arbre::maxRadius(float length) {
+	return length * (1+limitLengthFactor);
+}
+
+void Arbre::tronc() {
+	float radius = length/16;
+	Vertex hTronc = end(1.f) - start;
+	Vertex uTronc = rotation.u * radius;
+	Vertex lTronc = rotation.l * radius;
+	Quad cTronc(start +uTronc +lTronc, start -uTronc +lTronc, start -uTronc -lTronc, start +uTronc -lTronc);
+	addGPUQuad(cTronc + hTronc, Couleurs::tronc);
+	addGPUFourQuads(cTronc, cTronc + hTronc, Couleurs::tronc);
+}
+
+void Arbre::feuille() {
+	Vertex hFeuillage = rotation.h * limitLength();
+	Vertex uFeuillage = rotation.u * limitLength() / 2.f;
+	Vertex lFeuillage = rotation.l * limitLength() / 2.f;
+	Vertex startFeuillage = end(1.f);
+
+	Quad cFeuillage(startFeuillage +uFeuillage +lFeuillage, startFeuillage -uFeuillage +lFeuillage, startFeuillage -uFeuillage -lFeuillage, startFeuillage +uFeuillage -lFeuillage);
+	addGPUOcto(cFeuillage, cFeuillage + hFeuillage, Couleurs::feuillage);
+}
diff --git a/rules/architecture/arbre.hh b/rules/architecture/arbre.hh
new file mode 100644
index 0000000..8e074f1
--- /dev/null
+++ b/rules/architecture/arbre.hh
@@ -0,0 +1,34 @@
+#ifndef _RULES_ARCHITECTURE_ARBRE_HH_
+#define _RULES_ARCHITECTURE_ARBRE_HH_
+
+#include "all_includes.hh"
+
+class Arbre : public Chose {
+public:
+	enum Type {
+		ARBRE,
+		TRONC
+	};
+private:
+	Vertex start;
+	Angle3D rotation;
+	float length;
+	Type type;
+	Vertex end(float position) const;
+	float limitLength() const;
+	static float tauxMax();
+	static float calcLimitLengthFactor();
+	static const float limitLengthFactor;
+public:
+	static float maxRadius(float length);
+	Arbre(Vertex _start, Triangle plane);
+	Arbre(Vertex _start, Angle3D _rotation, float _length, Type _type = ARBRE);
+	virtual bool split();
+	virtual void triangulation();
+	virtual void getBoundingBoxPoints();
+	virtual float LODFactor();
+	void tronc();
+	void feuille();
+};
+
+#endif
diff --git a/rules/architecture/batiment.cpp b/rules/architecture/batiment.cpp
index 0dc8767..34548e3 100644
--- a/rules/architecture/batiment.cpp
+++ b/rules/architecture/batiment.cpp
@@ -6,7 +6,7 @@ BatimentQuad_::BatimentQuad_(Quad _c, bool _isSub, bool _we, bool _ws, bool _ww,
 }
 
 bool BatimentQuad_::split() {
-	int minSurface = 100 * 100 * 10;
+	int minSurface = 100 * 100 * 100;
 	Quad q = c;
 	//Quad q = c << c.maxLengthSide();
 	if(c.maxLengthNS() < c.maxLengthEW()) {
diff --git a/rules/architecture/couleursDimensions.hh b/rules/architecture/couleursDimensions.hh
index 06e7c56..6ba0a50 100644
--- a/rules/architecture/couleursDimensions.hh
+++ b/rules/architecture/couleursDimensions.hh
@@ -24,7 +24,9 @@ public:
 	static const unsigned int route = 0x363636;
 	static const unsigned int trottoir = 0x666666;
 	static const unsigned int bordureTrottoir = 0xAAAAAA;
-	static const unsigned int herbe = 0x0c4010; // 11AA22
+	static const unsigned int herbe = 0x0c4010;
+	static const unsigned int feuillage = 0x11AA22;
+	static const unsigned int tronc = 0x906050;
 	static const unsigned int cielHaut = 0x3c14ff;
 	static const unsigned int cielBas = 0x7F7FFF;
 	static const unsigned int fog; // définie dans couleurs.cpp .
diff --git a/rules/architecture/quartier.cpp b/rules/architecture/quartier.cpp
index d2243fc..7afb614 100644
--- a/rules/architecture/quartier.cpp
+++ b/rules/architecture/quartier.cpp
@@ -135,6 +135,18 @@ void QuartierQuad::batiments() {
 		addChild(new BatimentQuad_(qbatiments));
 	} else {
 		addChild(new TerrainQuad(qbatiments));
+		Vertex p1 = qbatiments.insetProportionnal(0.7).randomPoint(seed, 1);
+		Vertex p2 = qbatiments.insetProportionnal(0.7).randomPoint(seed, 2);
+		Vertex p3 = qbatiments.insetProportionnal(0.7).randomPoint(seed, 3);
+		if (proba(seed, 4, 3, 4)) {
+			addChild(new Arbre(p1, Triangle(qbatiments[NE], qbatiments[SE], qbatiments[SW])));
+			if (proba(seed, 5, 3, 4) && Segment(p1,p2).length() > 3 * 100) {
+				addChild(new Arbre(p2, Triangle(qbatiments[NE], qbatiments[SE], qbatiments[SW])));
+				if (proba(seed, 6, 3, 4) && Segment(p2,p3).length() > 3 * 100 && Segment(p1,p3).length() > 3 * 100) {
+					addChild(new Arbre(p3, Triangle(qbatiments[NE], qbatiments[SE], qbatiments[SW])));
+				}
+			}
+		}
 	}
 }
 
diff --git a/rules/architecture/toit.cpp b/rules/architecture/toit.cpp
index a18c119..12a9d95 100644
--- a/rules/architecture/toit.cpp
+++ b/rules/architecture/toit.cpp
@@ -12,12 +12,12 @@ void ToitQuad::getBoundingBoxPoints() {
 }
 
 void ToitQuad::triangulation() {
-	switch (hash2(seed, -1) % 4) {
+	switch (hash2(seed, -1) % 5) {
 	case 0: pointCentral(); break;
-	// TODO : deuxPoints() et deuxPointsVerticaux() ne génèrent pas des quad où les 4 points sont sur le même plan.
-	case 1: deuxPoints(); break;
-	case 2: deuxPointsVerticaux(); break;
-	case 3:
+	case 1: quatrePoints(); break;
+	case 2: deuxPoints(); break;
+	case 3: deuxPointsVerticaux(); break;
+	case 4:
 	default: plat(); break;
 	}
 }
@@ -29,6 +29,13 @@ void ToitQuad::pointCentral() {
 		addGPUTriangle(c[SE+i], center, c[NE+i], Couleurs::toit);
 }
 
+void ToitQuad::quatrePoints() {
+	Quad ch = c.offsetNormal(height).insetNESW(c.minLength() / 3.f); // TODO : insetProportional
+	addGPUQuad(ch, Couleurs::toit);
+	for (int i = 0; i < 4; i++)
+		addGPUQuad(ch[NE+i], c[NE+i], c[SE+i], ch[SE+i], Couleurs::toit);
+}
+
 void ToitQuad::deuxPoints() {
 	// Orienter c dans le sens de la longueur d'est en ouest.
 	Quad q = c >> ((c.maxLengthNS() > c.maxLengthEW()) ? 1 : 0);
@@ -111,7 +118,7 @@ void ToitTri::troisPoints() {
 	Triangle th = c.offsetNormal(height).insetLTR(c.minLength() / 3.f);
 	addGPUTriangle(th, Couleurs::toit);
 	for (int i = 0; i < 3; i++)
-		addGPUQuad(c[LEFT], c[TOP], th[TOP], th[LEFT], Couleurs::toit);
+		addGPUQuad(c[LEFT+i], c[TOP+i], th[TOP+i], th[LEFT+i], Couleurs::toit);
 }
 
 void ToitTri::unPointVertical() {
diff --git a/rules/architecture/toit.hh b/rules/architecture/toit.hh
index d9f0537..d4cb700 100644
--- a/rules/architecture/toit.hh
+++ b/rules/architecture/toit.hh
@@ -13,6 +13,7 @@ public:
 	virtual void getBoundingBoxPoints();
 private:
 	void pointCentral();
+	void quatrePoints();
 	void deuxPoints();
 	void deuxPointsVerticaux();
 	void plat();
diff --git a/rules/chose.cpp b/rules/chose.cpp
index 9aa9980..ed04014 100644
--- a/rules/chose.cpp
+++ b/rules/chose.cpp
@@ -48,6 +48,11 @@ void Chose::addGPUQuad(Quad q, unsigned int rgb) {
 	addGPUQuad(q[NE], q[SE], q[SW], q[NW], rgb);
 }
 
+void Chose::addGPUFourQuads(Quad q, Quad qh, unsigned int rgb) {
+	for (int i = 0; i < 4; i++)
+		addGPUQuad(Quad(qh[NE+i], q[NE+i], q[SE+i], qh[SE+i]), rgb);
+}
+
 void Chose::addGPUOcto(Vertex ne, Vertex se, Vertex sw, Vertex nw,
 		Vertex neh, Vertex seh, Vertex swh, Vertex nwh, unsigned int rgb) {
 	addGPUOcto(Quad(ne,se,sw,nw), Quad(neh,seh,swh,nwh), rgb);
@@ -131,8 +136,8 @@ void Chose::addBBPoints(const Quad q, float height) {
 }
 
 void Chose::updateAABB() {
-	float splitFactor = 5.f;
-	float mergeFactor = 6.f;
+	float splitFactor = 5.f * LODFactor();
+	float mergeFactor = 6.f * LODFactor();
 	float nonFacingFactor = 2.f/3.f;
 	lod.firstBBPoint = true;
 	getBoundingBoxPoints();
@@ -153,6 +158,10 @@ void Chose::updateAABB() {
 	}
 }
 
+float Chose::LODFactor() {
+	return 1.f;
+}
+
 // DEBUG
 void Chose::drawAABB() {
 	addGPUOcto(
diff --git a/rules/chose.hh b/rules/chose.hh
index f6dfe22..4e35a4c 100644
--- a/rules/chose.hh
+++ b/rules/chose.hh
@@ -28,6 +28,7 @@ protected :
 	void addBBPoints(const Quad q);
 	void addBBPoints(const Quad q, float height);
 	virtual void getBoundingBoxPoints() = 0;
+	virtual float LODFactor();
 	Chose();
 	~Chose();
 	inline void addEntropy(unsigned int x1) {
@@ -66,6 +67,7 @@ protected :
 	void addGPUTriangle(Triangle t, unsigned int rgb);
 	void addGPUQuad(Vertex ne, Vertex se, Vertex sw, Vertex nw, unsigned int rgb);
 	void addGPUQuad(Quad q, unsigned int rgb);
+	void addGPUFourQuads(Quad q, Quad qh, unsigned int rgb);
 	void addGPUOcto(Vertex ne, Vertex se, Vertex sw, Vertex nw,
 			Vertex neh, Vertex seh, Vertex swh, Vertex nwh,
 			unsigned int rgb);