diff --git a/qglengine/core/glshaders_headers.h b/qglengine/core/glshaders_headers.h
index de625aa..28a3447 100644
--- a/qglengine/core/glshaders_headers.h
+++ b/qglengine/core/glshaders_headers.h
@@ -95,14 +95,8 @@ const char qgl_structs[] =
 	"};\n"
 	"struct QGLLightParameter {\n"
 	"	vec4 color;\n"
-	"	float intensity;\n"
-	"	float startAngle;\n"
-	"	float startAngleCos;\n"
-	"	float endAngle;\n"
-	"	float endAngleCos;\n"
-	"	float constantAttenuation;\n"
-	"	float linearAttenuation;\n"
-	"	float quadraticAttenuation;\n"
+	"	vec4 decay_intensity;\n"
+	"	vec4 angles;\n"
 	//"	sampler2DShadow shadow;\n"
 	//"	sampler2D shadowColor\n"
 	//"	mat4 shadowMatrix;\n"
diff --git a/qglengine/core/glshaders_types.h b/qglengine/core/glshaders_types.h
index 9db90c4..a7b7180 100644
--- a/qglengine/core/glshaders_types.h
+++ b/qglengine/core/glshaders_types.h
@@ -124,15 +124,8 @@ struct QGLMaterial {
 };
 struct QGLLightParameter {
 	QVector4D color;
-	//QVector4D shadowColor;
-	GLfloat intensity;
-	GLfloat startAngle;
-	GLfloat startAngleCos;
-	GLfloat endAngle;
-	GLfloat endAngleCos;
-	GLfloat constantAttenuation;
-	GLfloat linearAttenuation;
-	GLfloat quadraticAttenuation;
+	QVector4D decay_intensity; // [^0, ^1, ^2, intensity]
+	QVector4D angles; // [start, cos(start), end, cos(end)]
 	//GLfloat shadow;
 	//GLfloat shadowMatrix[16];
 };
diff --git a/qglengine/core/gltransform.cpp b/qglengine/core/gltransform.cpp
index cafdd54..df2e793 100644
--- a/qglengine/core/gltransform.cpp
+++ b/qglengine/core/gltransform.cpp
@@ -158,6 +158,15 @@ Transform::Transform(): m_scale(1.0f, 1.0f, 1.0f),
 }
 
 
+Transform & Transform::operator =(const Transform & t) {
+	m_scale = t.m_scale;
+	m_translation = t.m_translation;
+	m_eulerRotationAngles = t.m_eulerRotationAngles;
+	m_matrixDirty = true;
+	return *this;
+}
+
+
 void Transform::setMatrix(const QMatrix4x4 & m) {
 	if (m != matrix()) {
 		m_matrix = m;
diff --git a/qglengine/core/gltransform.h b/qglengine/core/gltransform.h
index 84bc887..3efc689 100644
--- a/qglengine/core/gltransform.h
+++ b/qglengine/core/gltransform.h
@@ -29,6 +29,7 @@ class Transform {
 	friend QDataStream & operator >>(QDataStream & s, Transform & v);
 public:
 	Transform();
+	Transform & operator =(const Transform & t);
 
 	float scale() const;
 	QVector3D scale3D() const;
@@ -61,6 +62,7 @@ public:
 	void setTranslationZ(float t);
 
 	void setMatrix(const QMatrix4x4 & matrix);
+	void setDirty(bool yes = true) {m_matrixDirty = yes;}
 
 
 	static QQuaternion fromAxisAndAngle(const QVector3D & axis, float angle);
diff --git a/qglengine/formats/loader_assimp.cpp b/qglengine/formats/loader_assimp.cpp
index 14724a7..5fd6790 100644
--- a/qglengine/formats/loader_assimp.cpp
+++ b/qglengine/formats/loader_assimp.cpp
@@ -132,6 +132,8 @@ Material * assimpMaterial(const aiMaterial * m) {
 
 Light * assimpLight(const aiLight * l) {
 	if (!l) return 0;
+	if (l->mType != aiLightSource_POINT && l->mType != aiLightSource_SPOT)
+		return 0;
 	Light * ret = new Light();
 	ret->setName(fromAiString(l->mName));
 	ret->setPos(fromAiVector3D(l->mPosition));
@@ -221,28 +223,32 @@ Scene * loadScene(const QString & filepath) {
 		lights << assimpLight(ais->mLights[i]);
 	QMap<QString, Light * > light_by_name;
 	foreach (Light * l, lights)
-		light_by_name[l->name()] = l;
+		if (l)
+			light_by_name[l->name()] = l;
 
 	QVector<Light*> out_lights;
 	ObjectBaseList rootl = assimpObject(ais->mRootNode, meshes, ais->mMeshes, materials, light_by_name, out_lights);
 	if (rootl.isEmpty()) return 0;
 	ObjectBase * root = rootl[0];
+	root->transferTransformToChildren(true);
 
 	ObjectBaseList rcl = root->children(true);
 	foreach (ObjectBase * c, rcl) {
 		foreach (Light * l, out_lights) {
 			if (c->name() == (l->name() + ".Target")) {
-				l->setAim((l->worldTransform().inverted() * QVector4D(c->worldPos(), 1)).toVector3D());
+				l->setDistance((l->worldPos() - c->worldPos()).length());
 				delete c;
 				break;
 			}
 		}
 	}
+	root->cleanTree();
 
 	Scene * scene = new Scene();
 	scene->setName(root->name());
 	foreach (ObjectBase * o, root->children())
 		scene->addObject(o);
+	lights.removeAll(0);
 	qDeleteAll(lights);
 
 	return scene;
diff --git a/qglengine/globject.cpp b/qglengine/globject.cpp
index 44d5ce4..5224aea 100644
--- a/qglengine/globject.cpp
+++ b/qglengine/globject.cpp
@@ -273,6 +273,11 @@ void ObjectBase::calculateBoundingBox() {
 }
 
 
+void ObjectBase::updateTransform() {
+	buildTransform(true);
+}
+
+
 void ObjectBase::setProperty(const QString & pn, const QVariant & v) {
 	meta[pn] = v;
 }
@@ -316,6 +321,28 @@ QVector3D ObjectBase::inParentSpace(const QVector3D & v) const {
 }
 
 
+void ObjectBase::transferTransformToChildren(bool only_scale) {
+	QMatrix4x4 m = trans.matrix();
+	if (only_scale) m = trans.matrixScale();
+	foreach (ObjectBase * i, children_)
+		i->trans.setMatrix(m * i->trans.matrix());
+	if (only_scale) resetScale();
+	else setMatrix(QMatrix4x4());
+}
+
+
+void ObjectBase::cleanTree() {
+	for (int i = 0; i < children_.size(); ++i) {
+		ObjectBase * o = children_[i];
+		if (!o->hasChildren() && !o->mesh() && (o->type() == glMesh)) {
+			delete o;
+			--i;
+		}
+		o->cleanTree();
+	}
+}
+
+
 bool ObjectBase::isSelected(bool check_parents) const {
 	if (!check_parents) return selected_;
 	if (selected_) return true;
@@ -373,7 +400,8 @@ void ObjectBase::setMesh(Mesh * v) {
 }
 
 
-void ObjectBase::buildTransform() {
+void ObjectBase::buildTransform(bool force) {
+	if (force) trans.setDirty();
 	itransform_.setToIdentity();
 	ObjectBase * p = parent_;
 	if (p)
@@ -386,7 +414,7 @@ void ObjectBase::buildTransform() {
 		localTransform(itransform_);
 	//qDebug() << name_ << itransform_;
 	foreach (ObjectBase * i, children_)
-		i->buildTransform();
+		i->buildTransform(force);
 	setObjectsChanged();
 }
 
diff --git a/qglengine/globject.h b/qglengine/globject.h
index 6754235..a797c3d 100644
--- a/qglengine/globject.h
+++ b/qglengine/globject.h
@@ -63,7 +63,7 @@ public:
 	ObjectBase * parent() {return parent_;}
 	void setParent(ObjectBase * o) {parent_ = o;}
 	bool hasParent() const {return parent_ != nullptr;}
-	bool hasChildren() const {return children_.size() != 0;}
+	bool hasChildren() const {return !children_.isEmpty();}
 	void setScene(Scene * v);
 
 	void addChild(ObjectBase * o);
@@ -147,6 +147,8 @@ public:
 	QMatrix4x4 matrix() const;
 	bool isRawMatrix() {return raw_matrix;}
 	QVector3D inParentSpace(const QVector3D & v) const;
+	void transferTransformToChildren(bool only_scale = true);
+	void cleanTree();
 
 	bool isAcceptLight() const {return accept_light;}
 	void setAcceptLight(bool yes) {accept_light = yes;}
@@ -182,6 +184,7 @@ public:
 	Mesh * mesh() {return mesh_;}
 
 	void calculateBoundingBox();
+	void updateTransform();
 
 	void setProperty(const QString & pn, const QVariant & v);
 	QVariant property(const QString & pn, bool * exists = 0) const;
@@ -195,11 +198,11 @@ public:
 protected:
 	virtual void transformChanged() {}
 	void addChildren(ObjectBaseList & list, ObjectBase * where);
-	void buildTransform();
+	void buildTransform(bool force = false);
 	void initInternal();
 	void setSceneTreeChanged();
 	void setObjectsChanged();
-	virtual void localTransform(QMatrix4x4 & m);
+	void localTransform(QMatrix4x4 & m);
 	QMatrix4x4 worldMatrix(QMatrix4x4 parent) const;
 
 	int prev_pass; // Pass
diff --git a/qglengine/glscene.cpp b/qglengine/glscene.cpp
index 89fea9e..2bf22d3 100644
--- a/qglengine/glscene.cpp
+++ b/qglengine/glscene.cpp
@@ -474,7 +474,7 @@ void Scene::destroy() {
 
 
 void Scene::destroyUnused(QOpenGLExtraFunctions * f) {
-	if (!td_geometries.isEmpty()) qDebug() << "destroyUnused" << td_geometries.size();
+	//if (!td_geometries.isEmpty()) qDebug() << "destroyUnused" << td_geometries.size();
 	foreach (Mesh * i, td_geometries)
 		i->destroy(f);
 	qDeleteAll(td_geometries);
diff --git a/qglengine/renderer_base.cpp b/qglengine/renderer_base.cpp
index 5a0adfd..e22e877 100644
--- a/qglengine/renderer_base.cpp
+++ b/qglengine/renderer_base.cpp
@@ -233,15 +233,15 @@ void RendererBase::reloadLightsParameters(const QMap<int, QList<Light*>> & light
 		if (l->light_type == Light::Omni)
 			ang_start = ang_end = 180.;
 		//qDebug() << "light" << light->name() << ulightn << pos;
-		so.intensity = l->intensity;
-		so.startAngle = ang_start;
-		so.startAngleCos = cos(ang_start * deg2rad);
-		so.endAngle = ang_end;
-		so.endAngleCos = cos(ang_end * deg2rad);
 		so.color = QColor2QVector(l->color_);
-		so.constantAttenuation = l->decay_const;
-		so.linearAttenuation = l->decay_linear;
-		so.quadraticAttenuation = l->decay_quadratic;
+		so.angles[0] = ang_start;
+		so.angles[1] = cos(ang_start * deg2rad);
+		so.angles[2] = ang_end;
+		so.angles[3] = cos(ang_end * deg2rad);
+		so.decay_intensity[0] = l->decay_const;
+		so.decay_intensity[1] = l->decay_linear;
+		so.decay_intensity[2] = l->decay_quadratic;
+		so.decay_intensity[3] = l->intensity;
 		//so.shadow = shadow;
 		//so.shadowColor = shadow;
 	}
diff --git a/qglengine/widgets/scene_tree.cpp b/qglengine/widgets/scene_tree.cpp
index f960aae..9fcbac2 100644
--- a/qglengine/widgets/scene_tree.cpp
+++ b/qglengine/widgets/scene_tree.cpp
@@ -102,6 +102,7 @@ QList<QAction *> SceneTree::actionsSelection() {
 	ret << ui->actionFocus << newSeparator()
 		<< ui->actionGroup << ui->actionClone << newSeparator()
 		<< ui->actionSelect_parent << ui->actionSelect_by_mesh << ui->actionSelect_by_material << newSeparator()
+		<< ui->actionTransfer_transform_to_children << newSeparator()
 		<< ui->actionRemove;
 	return ret;
 }
@@ -387,6 +388,14 @@ void SceneTree::on_actionGroup_triggered() {
 }
 
 
+void SceneTree::on_actionTransfer_transform_to_children_triggered() {
+	if (!view) return;
+	ObjectBaseList sol = view->scene()->selectedObjects(true);
+	foreach (ObjectBase * o, sol)
+		o->transferTransformToChildren();
+}
+
+
 void SceneTree::on_actionSelect_parent_triggered() {
 	if (!view) return;
 	ObjectBaseList sol = view->scene()->selectedObjects(true);
diff --git a/qglengine/widgets/scene_tree.h b/qglengine/widgets/scene_tree.h
index 5cdad37..7caade0 100644
--- a/qglengine/widgets/scene_tree.h
+++ b/qglengine/widgets/scene_tree.h
@@ -71,6 +71,7 @@ private slots:
 	void on_actionRemove_triggered() {removeObjects();}
 	void on_actionClone_triggered();
 	void on_actionGroup_triggered();
+	void on_actionTransfer_transform_to_children_triggered();
 
 	void on_actionSelect_parent_triggered();
 	void on_actionSelect_by_mesh_triggered();
@@ -84,6 +85,7 @@ private slots:
 	void filter();
 	void __objectDeleted(ObjectBase * o);
 
+
 public slots:
 
 signals:
diff --git a/qglengine/widgets/scene_tree.ui b/qglengine/widgets/scene_tree.ui
index 44b8a06..7a98713 100644
--- a/qglengine/widgets/scene_tree.ui
+++ b/qglengine/widgets/scene_tree.ui
@@ -260,6 +260,11 @@
     <string>Cameras</string>
    </property>
   </action>
+  <action name="actionTransfer_transform_to_children">
+   <property name="text">
+    <string>Transfer transform to children</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>