calculate angle when set volume

src/libslic3r/Emboss.cpp

@@ -1544,7 +1544,7 @@ std::optional<Vec2d> Emboss::ProjectZ::unproject(const Vec3d &p, double *depth)
 Vec3d Emboss::suggest_up(const Vec3d normal, double up_limit) 
 {
     // Normal must be 1
-    assert(is_approx(normal.norm(), 1.));
+    assert(is_approx(normal.squaredNorm(), 1.));
 
     // wanted up direction of result
     Vec3d wanted_up_side = 
@@ -1560,28 +1560,45 @@ Vec3d Emboss::suggest_up(const Vec3d normal, double up_limit)
     return wanted_up_dir;
 }
 
+std::optional<float> Emboss::calc_up(const Transform3d &tr, double up_limit)
+{
+    auto tr_linear = tr.linear();
+    // z base of transformation ( tr * UnitZ )
+    Vec3d normal = tr_linear.col(2);
+    // scaled matrix has base with different size
+    normal.normalize();
+    Vec3d suggested = suggest_up(normal);
+    assert(is_approx(suggested.squaredNorm(), 1.));
+
+    Vec3d up = tr_linear.col(1); // tr * UnitY()
+    up.normalize();
+    
+    double dot = suggested.dot(up);
+    if (dot >= 1. || dot <= -1.)
+        return {}; // zero angle
+
+    Matrix3d m;
+    m.row(0) = up;
+    m.row(1) = suggested;
+    m.row(2) = normal;
+    double det = m.determinant();
+
+    return atan2(det, dot);
+}
+
 Transform3d Emboss::create_transformation_onto_surface(const Vec3d &position,
                                                        const Vec3d &normal,
                                                        float        up_limit)
 {
-    // up and emboss direction for generated model
-    Vec3d text_up_dir     = Vec3d::UnitY();
-    Vec3d text_emboss_dir = Vec3d::UnitZ();
+    // is normalized ?
+    assert(is_approx(normal.squaredNorm(), 1.));
 
-    // wanted up direction of result
-    Vec3d wanted_up_side = Vec3d::UnitZ();
-    if (std::fabs(normal.z()) > up_limit) wanted_up_side = Vec3d::UnitY();
+    // up and emboss direction for generated model
+    Vec3d up_dir     = Vec3d::UnitY();
+    Vec3d emboss_dir = Vec3d::UnitZ();
 
     // after cast from float it needs to be normalized again
-    assert(is_approx(normal.norm(), 1.));
-
-    // create perpendicular unit vector to surface triangle normal vector
-    // lay on surface of triangle and define up vector for text
-    Vec3d wanted_up_dir = normal
-        .cross(wanted_up_side)
-        .cross(normal);
-    // normal3d is NOT perpendicular to normal_up_dir
-    wanted_up_dir.normalize(); 
+    Vec3d wanted_up_dir = suggest_up(normal, up_limit);
 
     // perpendicular to emboss vector of text and normal
     Vec3d axis_view;
@@ -1591,25 +1608,24 @@ Transform3d Emboss::create_transformation_onto_surface(const Vec3d &position,
         axis_view = Vec3d::UnitY();
         angle_view = M_PI;
     } else {
-        axis_view = text_emboss_dir.cross(normal);
-        angle_view = std::acos(text_emboss_dir.dot(normal)); // in rad
+        axis_view = emboss_dir.cross(normal);
+        angle_view = std::acos(emboss_dir.dot(normal)); // in rad
         axis_view.normalize();
     }
 
     Eigen::AngleAxis view_rot(angle_view, axis_view);
     Vec3d wanterd_up_rotated = view_rot.matrix().inverse() * wanted_up_dir;
     wanterd_up_rotated.normalize();
-    double angle_up = std::acos(text_up_dir.dot(wanterd_up_rotated));
+    double angle_up = std::acos(up_dir.dot(wanterd_up_rotated));
 
-    // text_view and text_view2 should have same direction
-    Vec3d text_view2 = text_up_dir.cross(wanterd_up_rotated);
-    Vec3d diff_view  = text_emboss_dir - text_view2;
+    Vec3d text_view = up_dir.cross(wanterd_up_rotated);
+    Vec3d diff_view  = emboss_dir - text_view;
     if (std::fabs(diff_view.x()) > 1. ||
         std::fabs(diff_view.y()) > 1. ||
         std::fabs(diff_view.z()) > 1.) // oposit direction
         angle_up *= -1.;
 
-    Eigen::AngleAxis up_rot(angle_up, text_emboss_dir);
+    Eigen::AngleAxis up_rot(angle_up, emboss_dir);
 
     Transform3d transform = Transform3d::Identity();
     transform.translate(position);

src/libslic3r/Emboss.hpp

@@ -282,6 +282,14 @@ namespace Emboss
     /// <returns>Wanted up vector</returns>
     Vec3d suggest_up(const Vec3d normal, double up_limit = 0.9);
         
+    /// <summary>
+    /// By transformation calculate angle between suggested and actual up vector
+    /// </summary>
+    /// <param name="tr">Transformation of embossed volume in world</param>
+    /// <param name="up_limit">Is compared with normal.z to suggest up direction</param>
+    /// <returns>Rotation of suggested up-vector[in rad] in the range [-Pi, Pi], When rotation is not zero</returns>
+    std::optional<float> calc_up(const Transform3d &tr, double up_limit = 0.9);
+
     /// <summary>
     /// Create transformation for emboss text object to lay on surface point
     /// </summary>

src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp

@@ -103,8 +103,12 @@ static const struct Limits
         }
         return false;
     }
+
 } limits;
 
+// Define where is up vector on model
+constexpr double up_limit = 0.9;
+
 static bool is_text_empty(const std::string &text){
     return text.empty() ||
            text.find_first_not_of(" \n\t\r") == std::string::npos;
@@ -1239,7 +1243,8 @@ void GLGizmoEmboss::set_default_text(){ m_text = _u8L("Embossed text"); }
 
 void GLGizmoEmboss::set_volume_by_selection()
 {
-    ModelVolume *vol = priv::get_selected_volume(m_parent.get_selection());
+    const Selection &selection = m_parent.get_selection();
+    ModelVolume *vol = priv::get_selected_volume(selection);
     // is same volume selected?
     if (vol != nullptr && vol->id() == m_volume_id) 
         return;
@@ -1259,6 +1264,13 @@ void GLGizmoEmboss::set_volume_by_selection()
 
     // is select embossed volume?
     set_volume(vol);
+
+    // Check if user changed up vector by rotation or scale out of emboss gizmo
+    if (m_volume != nullptr) {
+        Transform3d world = selection.get_first_volume()->world_matrix();
+        std::optional<float> angle = calc_up(world, priv::up_limit);
+        m_volume->text_configuration->style.prop.angle = angle;
+    }
 }
 
 bool GLGizmoEmboss::set_volume(ModelVolume *volume)
@@ -3563,31 +3575,6 @@ void GLGizmoEmboss::draw_advanced()
     } else if (ImGui::IsItemHovered()) {
         ImGui::SetTooltip("%s", _u8L("Use camera direction for text orientation").c_str());
     }
-
-    ImGui::SameLine();
-    if (ImGui::Button(_u8L("Reset Up").c_str())) {
-        GLVolume *gl_volume = priv::get_gl_volume(m_parent);
-        if (gl_volume != nullptr) {
-            Transform3d world = gl_volume->world_matrix();
-            auto world_linear = world.linear();
-            Vec3d z_world = world_linear.col(2);
-            z_world.normalize();
-            Vec3d wanted_up = suggest_up(z_world);
-
-            Vec3d y_world = world_linear.col(1);
-            auto z_rotation = Eigen::Quaternion<double, Eigen::DontAlign>::FromTwoVectors(y_world, wanted_up);
-            Transform3d world_new = z_rotation * world;
-            auto world_new_linear = world_new.linear();
-            Transform3d volume_new = gl_volume->get_volume_transformation().get_matrix();
-            Transform3d instance = gl_volume->get_instance_transformation().get_matrix();
-            volume_new.linear() = instance.linear().inverse() * world_new.linear();
-            gl_volume->set_volume_transformation(volume_new);
-            m_parent.do_move(L("Reset up vector"));
-        }
-    } else if (ImGui::IsItemHovered()) {
-        ImGui::SetTooltip("%s", _u8L("Reset skew of text to be normal in world").c_str());
-    }
-
 #ifdef ALLOW_DEBUG_MODE
     ImGui::Text("family = %s", (font_prop.family.has_value() ?
                                     font_prop.family->c_str() :
@@ -4079,7 +4066,7 @@ bool priv::start_create_volume_on_surface_job(
     Transform3d instance = gl_volume->get_instance_transformation().get_matrix();
 
     // Create result volume transformation
-    Transform3d surface_trmat = create_transformation_onto_surface(hit->position, hit->normal);
+    Transform3d surface_trmat = create_transformation_onto_surface(hit->position, hit->normal, priv::up_limit);
     const FontProp &font_prop = emboss_data.text_configuration.style.prop;
     apply_transformation(font_prop, surface_trmat);
     // new transformation in world coor is surface_trmat