diff --git a/resources/shaders/gouraud.fs b/resources/shaders/gouraud.fs
index f6116eec7..b2bc915ab 100644
--- a/resources/shaders/gouraud.fs
+++ b/resources/shaders/gouraud.fs
@@ -8,16 +8,22 @@ varying vec2 intensity;
 varying vec3 delta_box_min;
 varying vec3 delta_box_max;
 
-varying float world_z;
+varying vec3 world_pos;
 
 uniform vec4 uniform_color;
 
 // x = min z, y = max z;
 uniform vec2 z_range;
 
+// clipping plane (general orientation):
+uniform vec4 clipping_plane;
+
 void main()
 {
-    if ((world_z < z_range.x) || (z_range.y < world_z))
+    if ((world_pos.z < z_range.x) || (z_range.y < world_pos.z))
+        discard;
+
+    if (world_pos.x*clipping_plane.x + world_pos.y*clipping_plane.y + world_pos.z*clipping_plane.z + clipping_plane.w < 0.0 )
         discard;
 
     // if the fragment is outside the print volume -> use darker color
diff --git a/resources/shaders/gouraud.vs b/resources/shaders/gouraud.vs
index 84ae51391..a226cf312 100644
--- a/resources/shaders/gouraud.vs
+++ b/resources/shaders/gouraud.vs
@@ -34,7 +34,7 @@ varying vec2 intensity;
 varying vec3 delta_box_min;
 varying vec3 delta_box_max;
 
-varying float world_z;
+varying vec3 world_pos;
 
 void main()
 {
@@ -69,5 +69,5 @@ void main()
     }    
 
     gl_Position = ftransform();
-    world_z = vec3(print_box.volume_world_matrix * gl_Vertex).z;
+    world_pos = vec3(print_box.volume_world_matrix * gl_Vertex);
 } 
diff --git a/src/admesh/stl.h b/src/admesh/stl.h
index 2c436b426..d682b2434 100644
--- a/src/admesh/stl.h
+++ b/src/admesh/stl.h
@@ -43,11 +43,21 @@ typedef Eigen::Matrix<float, 3, 1, Eigen::DontAlign> stl_normal;
 static_assert(sizeof(stl_vertex) == 12, "size of stl_vertex incorrect");
 static_assert(sizeof(stl_normal) == 12, "size of stl_normal incorrect");
 
-typedef struct {
+struct stl_facet {
   stl_normal normal;
   stl_vertex vertex[3];
   char       extra[2];
-} stl_facet;
+
+  stl_facet  rotated(const Eigen::Quaternion<float, Eigen::DontAlign> &rot) {
+    stl_facet out;
+    out.normal    = rot * this->normal;
+    out.vertex[0] = rot * this->vertex[0];
+    out.vertex[1] = rot * this->vertex[1];
+    out.vertex[2] = rot * this->vertex[2];
+    return out;
+  }
+};
+
 #define SIZEOF_STL_FACET       50
 
 static_assert(offsetof(stl_facet, normal) == 0, "stl_facet.normal has correct offset");
diff --git a/src/admesh/stlinit.cpp b/src/admesh/stlinit.cpp
index e2939b8af..911f4f5e8 100644
--- a/src/admesh/stlinit.cpp
+++ b/src/admesh/stlinit.cpp
@@ -41,10 +41,12 @@ stl_open(stl_file *stl, const char *file) {
   stl_count_facets(stl, file);
   stl_allocate(stl);
   stl_read(stl, 0, true);
-  if (!stl->error) fclose(stl->fp);
+  if (stl->fp != nullptr) {
+	  fclose(stl->fp);
+	  stl->fp = nullptr;
+  }
 }
 
-
 void
 stl_initialize(stl_file *stl) {
   memset(stl, 0, sizeof(stl_file));
@@ -118,7 +120,7 @@ stl_count_facets(stl_file *stl, const char *file) {
     }
 
     /* Read the int following the header.  This should contain # of facets */
-    bool header_num_faces_read = fread(&header_num_facets, sizeof(uint32_t), 1, stl->fp);
+    bool header_num_faces_read = fread(&header_num_facets, sizeof(uint32_t), 1, stl->fp) != 0;
 #ifndef BOOST_LITTLE_ENDIAN
     // Convert from little endian to big endian.
     stl_internal_reverse_quads((char*)&header_num_facets, 4);
@@ -257,7 +259,6 @@ stl_reallocate(stl_file *stl) {
    time running this for the stl and therefore we should reset our max and min stats. */
 void stl_read(stl_file *stl, int first_facet, bool first) {
   stl_facet facet;
-  int   i;
 
   if (stl->error) return;
 
@@ -268,7 +269,7 @@ void stl_read(stl_file *stl, int first_facet, bool first) {
   }
 
   char normal_buf[3][32];
-  for(i = first_facet; i < stl->stats.number_of_facets; i++) {
+  for(uint32_t i = first_facet; i < stl->stats.number_of_facets; i++) {
     if(stl->stats.type == binary)
       /* Read a single facet from a binary .STL file */
     {
@@ -366,17 +367,19 @@ void stl_facet_stats(stl_file *stl, stl_facet facet, bool &first)
   }
 }
 
-void
-stl_close(stl_file *stl) {
-  if (stl->error) return;
+void stl_close(stl_file *stl)
+{
+	assert(stl->fp == nullptr);
+	assert(stl->heads == nullptr);
+	assert(stl->tail == nullptr);
 
-  if(stl->neighbors_start != NULL)
-    free(stl->neighbors_start);
-  if(stl->facet_start != NULL)
-    free(stl->facet_start);
-  if(stl->v_indices != NULL)
-    free(stl->v_indices);
-  if(stl->v_shared != NULL)
-    free(stl->v_shared);
+	if (stl->facet_start != NULL)
+		free(stl->facet_start);
+	if (stl->neighbors_start != NULL)
+		free(stl->neighbors_start);
+	if (stl->v_indices != NULL)
+		free(stl->v_indices);
+	if (stl->v_shared != NULL)
+		free(stl->v_shared);
+	memset(stl, 0, sizeof(stl_file));
 }
-
diff --git a/src/libslic3r/Model.cpp b/src/libslic3r/Model.cpp
index e634dd138..ac4cd73ef 100644
--- a/src/libslic3r/Model.cpp
+++ b/src/libslic3r/Model.cpp
@@ -897,13 +897,13 @@ BoundingBoxf3 ModelObject::raw_bounding_box() const
                 throw std::invalid_argument("Can't call raw_bounding_box() with no instances");
 #endif // !ENABLE_GENERIC_SUBPARTS_PLACEMENT
 
-            TriangleMesh vol_mesh(v->mesh);
 #if ENABLE_GENERIC_SUBPARTS_PLACEMENT
-            vol_mesh.transform(inst_matrix * v->get_matrix());
-            bb.merge(vol_mesh.bounding_box());
+            bb.merge(v->mesh.transformed_bounding_box(inst_matrix * v->get_matrix()));
 #else
-            vol_mesh.transform(v->get_matrix());
-            bb.merge(this->instances.front()->transform_mesh_bounding_box(vol_mesh, true));
+            // unmaintaned
+            assert(false);
+            // vol_mesh.transform(v->get_matrix());
+            // bb.merge(this->instances.front()->transform_mesh_bounding_box(vol_mesh, true));
 #endif // ENABLE_GENERIC_SUBPARTS_PLACEMENT
         }
     return bb;
@@ -920,13 +920,13 @@ BoundingBoxf3 ModelObject::instance_bounding_box(size_t instance_idx, bool dont_
     {
         if (v->is_model_part())
         {
-            TriangleMesh mesh(v->mesh);
 #if ENABLE_GENERIC_SUBPARTS_PLACEMENT
-            mesh.transform(inst_matrix * v->get_matrix());
-            bb.merge(mesh.bounding_box());
+            bb.merge(v->mesh.transformed_bounding_box(inst_matrix * v->get_matrix()));
 #else
-            mesh.transform(v->get_matrix());
-            bb.merge(this->instances[instance_idx]->transform_mesh_bounding_box(mesh, dont_translate));
+            // not maintained
+            assert(false);
+            //mesh.transform(v->get_matrix());
+            //bb.merge(this->instances[instance_idx]->transform_mesh_bounding_box(mesh, dont_translate));
 #endif // ENABLE_GENERIC_SUBPARTS_PLACEMENT
         }
     }
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index a978a3175..66641a7f5 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -2528,14 +2528,17 @@ void PrintConfigDef::init_sla_params()
 
     def = this->add("pad_wall_height", coFloat);
     def->label = L("Pad wall height");
-    def->tooltip = L("Defines the cavity depth. Set to zero to disable the cavity.");
+    def->tooltip = L("Defines the pad cavity depth. Set to zero to disable the cavity. "
+                     "Be careful when enabling this feature, as some resins may "
+                     "produce an extreme suction effect inside the cavity, "
+                     "which makes pealing the print off the vat foil difficult.");
     def->category = L("Pad");
 //     def->tooltip = L("");
     def->sidetext = L("mm");
     def->min = 0;
     def->max = 30;
-    def->mode = comSimple;
-    def->default_value = new ConfigOptionFloat(5.0);
+    def->mode = comExpert;
+    def->default_value = new ConfigOptionFloat(0.);
 
     def = this->add("pad_max_merge_distance", coFloat);
     def->label = L("Max merge distance");
diff --git a/src/libslic3r/TriangleMesh.cpp b/src/libslic3r/TriangleMesh.cpp
index bfba364af..2d603661d 100644
--- a/src/libslic3r/TriangleMesh.cpp
+++ b/src/libslic3r/TriangleMesh.cpp
@@ -693,6 +693,16 @@ void TriangleMeshSlicer::init(TriangleMesh *_mesh, throw_on_cancel_callback_type
     }
 }
 
+
+
+void TriangleMeshSlicer::set_up_direction(const Vec3f& up)
+{
+    m_quaternion.setFromTwoVectors(up, Vec3f::UnitZ());
+    m_use_quaternion = true;
+}
+
+
+
 void TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<Polygons>* layers, throw_on_cancel_callback_type throw_on_cancel) const
 {
     BOOST_LOG_TRIVIAL(debug) << "TriangleMeshSlicer::slice";
@@ -795,7 +805,7 @@ void TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<Polygons
 void TriangleMeshSlicer::_slice_do(size_t facet_idx, std::vector<IntersectionLines>* lines, boost::mutex* lines_mutex, 
     const std::vector<float> &z) const
 {
-    const stl_facet &facet = this->mesh->stl.facet_start[facet_idx];
+    const stl_facet &facet = m_use_quaternion ? this->mesh->stl.facet_start[facet_idx].rotated(m_quaternion) : this->mesh->stl.facet_start[facet_idx];
     
     // find facet extents
     const float min_z = fminf(facet.vertex[0](2), fminf(facet.vertex[1](2), facet.vertex[2](2)));
@@ -860,26 +870,43 @@ TriangleMeshSlicer::FacetSliceType TriangleMeshSlicer::slice_facet(
     IntersectionPoint points[3];
     size_t            num_points = 0;
     size_t            point_on_layer = size_t(-1);
-    
+
     // Reorder vertices so that the first one is the one with lowest Z.
     // This is needed to get all intersection lines in a consistent order
     // (external on the right of the line)
     const int *vertices = this->mesh->stl.v_indices[facet_idx].vertex;
     int i = (facet.vertex[1].z() == min_z) ? 1 : ((facet.vertex[2].z() == min_z) ? 2 : 0);
+
+    // These are used only if the cut plane is tilted:
+    stl_vertex rotated_a;
+    stl_vertex rotated_b;
+
     for (int j = i; j - i < 3; ++j) {  // loop through facet edges
         int        edge_id  = this->facets_edges[facet_idx * 3 + (j % 3)];
         int        a_id     = vertices[j % 3];
         int        b_id     = vertices[(j+1) % 3];
-        const stl_vertex *a = &this->v_scaled_shared[a_id];
-        const stl_vertex *b = &this->v_scaled_shared[b_id];
+
+        const stl_vertex *a;
+        const stl_vertex *b;
+        if (m_use_quaternion) {
+            rotated_a = m_quaternion * this->v_scaled_shared[a_id];
+            rotated_b = m_quaternion * this->v_scaled_shared[b_id];
+            a = &rotated_a;
+            b = &rotated_b;
+        }
+        else {
+            a = &this->v_scaled_shared[a_id];
+            b = &this->v_scaled_shared[b_id];
+        }
         
         // Is edge or face aligned with the cutting plane?
         if (a->z() == slice_z && b->z() == slice_z) {
             // Edge is horizontal and belongs to the current layer.
-            const stl_vertex &v0 = this->v_scaled_shared[vertices[0]];
-            const stl_vertex &v1 = this->v_scaled_shared[vertices[1]];
-            const stl_vertex &v2 = this->v_scaled_shared[vertices[2]];
-            const stl_normal &normal = this->mesh->stl.facet_start[facet_idx].normal;
+            // The following rotation of the three vertices may not be efficient, but this branch happens rarely.
+            const stl_vertex &v0 = m_use_quaternion ? stl_vertex(m_quaternion * this->v_scaled_shared[vertices[0]]) : this->v_scaled_shared[vertices[0]];
+            const stl_vertex &v1 = m_use_quaternion ? stl_vertex(m_quaternion * this->v_scaled_shared[vertices[1]]) : this->v_scaled_shared[vertices[1]];
+            const stl_vertex &v2 = m_use_quaternion ? stl_vertex(m_quaternion * this->v_scaled_shared[vertices[2]]) : this->v_scaled_shared[vertices[2]];
+            const stl_normal &normal = facet.normal;
             // We may ignore this edge for slicing purposes, but we may still use it for object cutting.
             FacetSliceType    result = Slicing;
             if (min_z == max_z) {
@@ -995,7 +1022,9 @@ TriangleMeshSlicer::FacetSliceType TriangleMeshSlicer::slice_facet(
             if (i == line_out->a_id || i == line_out->b_id)
                 i = vertices[2];
             assert(i != line_out->a_id && i != line_out->b_id);
-            line_out->edge_type = (this->v_scaled_shared[i].z() < slice_z) ? feTop : feBottom;
+            line_out->edge_type = ((m_use_quaternion ?
+                                    (m_quaternion * this->v_scaled_shared[i]).z()
+                                    : this->v_scaled_shared[i].z()) < slice_z) ? feTop : feBottom;
         }
 #endif
         return Slicing;
diff --git a/src/libslic3r/TriangleMesh.hpp b/src/libslic3r/TriangleMesh.hpp
index d389500c6..4bf5ce039 100644
--- a/src/libslic3r/TriangleMesh.hpp
+++ b/src/libslic3r/TriangleMesh.hpp
@@ -25,9 +25,10 @@ public:
     TriangleMesh(const Pointf3s &points, const std::vector<Vec3crd> &facets);
     TriangleMesh(const TriangleMesh &other) : repaired(false) { stl_initialize(&this->stl); *this = other; }
     TriangleMesh(TriangleMesh &&other) : repaired(false) { stl_initialize(&this->stl); this->swap(other); }
-    ~TriangleMesh() { stl_close(&this->stl); }
+    ~TriangleMesh() { clear(); }
     TriangleMesh& operator=(const TriangleMesh &other);
     TriangleMesh& operator=(TriangleMesh &&other) { this->swap(other); return *this; }
+    void clear() { stl_close(&this->stl); this->repaired = false; }
     void swap(TriangleMesh &other) { std::swap(this->stl, other.stl); std::swap(this->repaired, other.repaired); }
     void ReadSTLFile(const char* input_file) { stl_open(&stl, input_file); }
     void write_ascii(const char* output_file) { stl_write_ascii(&this->stl, output_file, ""); }
@@ -171,6 +172,7 @@ public:
     FacetSliceType slice_facet(float slice_z, const stl_facet &facet, const int facet_idx,
         const float min_z, const float max_z, IntersectionLine *line_out) const;
     void cut(float z, TriangleMesh* upper, TriangleMesh* lower) const;
+    void set_up_direction(const Vec3f& up);
     
 private:
     const TriangleMesh      *mesh;
@@ -178,6 +180,10 @@ private:
     std::vector<int>         facets_edges;
     // Scaled copy of this->mesh->stl.v_shared
     std::vector<stl_vertex>  v_scaled_shared;
+    // Quaternion that will be used to rotate every facet before the slicing
+    Eigen::Quaternion<float, Eigen::DontAlign> m_quaternion;
+    // Whether or not the above quaterion should be used
+    bool                     m_use_quaternion = false;
 
     void _slice_do(size_t facet_idx, std::vector<IntersectionLines>* lines, boost::mutex* lines_mutex, const std::vector<float> &z) const;
     void make_loops(std::vector<IntersectionLine> &lines, Polygons* loops) const;
diff --git a/src/slic3r/GUI/3DScene.cpp b/src/slic3r/GUI/3DScene.cpp
index 1dd136517..9038e388c 100644
--- a/src/slic3r/GUI/3DScene.cpp
+++ b/src/slic3r/GUI/3DScene.cpp
@@ -774,6 +774,7 @@ void GLVolumeCollection::render_VBOs(GLVolumeCollection::ERenderType type, bool
     glsafe(::glGetIntegerv(GL_CURRENT_PROGRAM, &current_program_id));
     GLint color_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "uniform_color") : -1;
     GLint z_range_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "z_range") : -1;
+    GLint clipping_plane_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "clipping_plane") : -1;
     GLint print_box_min_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.min") : -1;
     GLint print_box_max_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.max") : -1;
     GLint print_box_detection_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.volume_detection") : -1;
@@ -789,6 +790,9 @@ void GLVolumeCollection::render_VBOs(GLVolumeCollection::ERenderType type, bool
     if (z_range_id != -1)
         glsafe(::glUniform2fv(z_range_id, 1, (const GLfloat*)z_range));
 
+    if (clipping_plane_id != -1)
+        glsafe(::glUniform4fv(clipping_plane_id, 1, (const GLfloat*)clipping_plane));
+
     GLVolumeWithIdAndZList to_render = volumes_to_render(this->volumes, type, view_matrix, filter_func);
     for (GLVolumeWithIdAndZ& volume : to_render) {
         volume.first->set_render_color();
diff --git a/src/slic3r/GUI/3DScene.hpp b/src/slic3r/GUI/3DScene.hpp
index f8f29d270..88547359e 100644
--- a/src/slic3r/GUI/3DScene.hpp
+++ b/src/slic3r/GUI/3DScene.hpp
@@ -433,6 +433,9 @@ private:
     // z range for clipping in shaders
     float z_range[2];
 
+    // plane coeffs for clipping in shaders
+    float clipping_plane[4];
+
 public:
     GLVolumePtrs volumes;
 
@@ -491,6 +494,7 @@ public:
     }
 
     void set_z_range(float min_z, float max_z) { z_range[0] = min_z; z_range[1] = max_z; }
+    void set_clipping_plane(const double* coeffs) { clipping_plane[0] = coeffs[0]; clipping_plane[1] = coeffs[1]; clipping_plane[2] = coeffs[2]; clipping_plane[3] = coeffs[3]; }
 
     // returns true if all the volumes are completely contained in the print volume
     // returns the containment state in the given out_state, if non-null
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index f911dd171..44181ffcb 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -3521,7 +3521,15 @@ void GLCanvas3D::_picking_pass() const
 
         glsafe(::glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT));
 
+        m_camera_clipping_plane = m_gizmos.get_sla_clipping_plane();
+        if (! m_use_VBOs) {
+            ::glClipPlane(GL_CLIP_PLANE0, (GLdouble*)m_camera_clipping_plane.get_data());
+            ::glEnable(GL_CLIP_PLANE0);
+        }
         _render_volumes_for_picking();
+        if (! m_use_VBOs)
+            ::glDisable(GL_CLIP_PLANE0);
+
         m_gizmos.render_current_gizmo_for_picking_pass(m_selection);
 
         if (m_multisample_allowed)
@@ -3602,6 +3610,8 @@ void GLCanvas3D::_render_axes() const
     m_bed.render_axes();
 }
 
+
+
 void GLCanvas3D::_render_objects() const
 {
     if (m_volumes.empty())
@@ -3610,6 +3620,8 @@ void GLCanvas3D::_render_objects() const
     glsafe(::glEnable(GL_LIGHTING));
     glsafe(::glEnable(GL_DEPTH_TEST));
 
+    m_camera_clipping_plane = m_gizmos.get_sla_clipping_plane();
+
     if (m_use_VBOs)
     {
         if (m_picking_enabled)
@@ -3630,6 +3642,8 @@ void GLCanvas3D::_render_objects() const
         else
             m_volumes.set_z_range(-FLT_MAX, FLT_MAX);
 
+        m_volumes.set_clipping_plane(m_camera_clipping_plane.get_data());
+
         m_shader.start_using();
         if (m_picking_enabled && m_layers_editing.is_enabled() && m_layers_editing.last_object_id != -1) {
 			int object_id = m_layers_editing.last_object_id;
@@ -3650,13 +3664,17 @@ void GLCanvas3D::_render_objects() const
     }
     else
     {
+        ::glClipPlane(GL_CLIP_PLANE0, (GLdouble*)m_camera_clipping_plane.get_data());
+        ::glEnable(GL_CLIP_PLANE0);
+
         if (m_use_clipping_planes)
         {
-            glsafe(::glClipPlane(GL_CLIP_PLANE0, (GLdouble*)m_clipping_planes[0].get_data()));
-            glsafe(::glEnable(GL_CLIP_PLANE0));
-            glsafe(::glClipPlane(GL_CLIP_PLANE1, (GLdouble*)m_clipping_planes[1].get_data()));
+            glsafe(::glClipPlane(GL_CLIP_PLANE1, (GLdouble*)m_clipping_planes[0].get_data()));
             glsafe(::glEnable(GL_CLIP_PLANE1));
+            glsafe(::glClipPlane(GL_CLIP_PLANE2, (GLdouble*)m_clipping_planes[1].get_data()));
+            glsafe(::glEnable(GL_CLIP_PLANE2));
         }
+        
 
         // do not cull backfaces to show broken geometry, if any
         m_volumes.render_legacy(GLVolumeCollection::Opaque, m_picking_enabled, m_camera.get_view_matrix(), [this](const GLVolume& volume) {
@@ -3664,13 +3682,16 @@ void GLCanvas3D::_render_objects() const
         });
         m_volumes.render_legacy(GLVolumeCollection::Transparent, false, m_camera.get_view_matrix());
 
+        ::glDisable(GL_CLIP_PLANE0);
+
         if (m_use_clipping_planes)
         {
-            glsafe(::glDisable(GL_CLIP_PLANE0));
             glsafe(::glDisable(GL_CLIP_PLANE1));
+            glsafe(::glDisable(GL_CLIP_PLANE2));
         }
     }
-
+    
+    m_camera_clipping_plane = ClippingPlane::ClipsNothing();
     glsafe(::glDisable(GL_LIGHTING));
 }
 
diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index 228e3ca89..2486753e7 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -65,6 +65,35 @@ public:
     void set_scale_factor(int height);
 };
 
+
+class ClippingPlane
+{
+    double m_data[4];
+
+public:
+    ClippingPlane()
+    {
+        m_data[0] = 0.0;
+        m_data[1] = 0.0;
+        m_data[2] = 1.0;
+        m_data[3] = 0.0;
+    }
+
+    ClippingPlane(const Vec3d& direction, double offset)
+    {
+        Vec3d norm_dir = direction.normalized();
+        m_data[0] = norm_dir(0);
+        m_data[1] = norm_dir(1);
+        m_data[2] = norm_dir(2);
+        m_data[3] = offset;
+    }
+
+    static ClippingPlane ClipsNothing() { return ClippingPlane(Vec3d(0., 0., 1.), DBL_MAX); }
+
+    const double* get_data() const { return m_data; }
+};
+
+
 wxDECLARE_EVENT(EVT_GLCANVAS_OBJECT_SELECT, SimpleEvent);
 
 using Vec2dEvent = Event<Vec2d>;
@@ -288,32 +317,6 @@ class GLCanvas3D
         }
     };
 
-public:
-    class ClippingPlane
-    {
-        double m_data[4];
-
-    public:
-        ClippingPlane()
-        {
-            m_data[0] = 0.0;
-            m_data[1] = 0.0;
-            m_data[2] = 1.0;
-            m_data[3] = 0.0;
-        }
-
-        ClippingPlane(const Vec3d& direction, double offset)
-        {
-            Vec3d norm_dir = direction.normalized();
-            m_data[0] = norm_dir(0);
-            m_data[1] = norm_dir(1);
-            m_data[2] = norm_dir(2);
-            m_data[3] = offset;
-        }
-
-        const double* get_data() const { return m_data; }
-    };
-
 private:
     struct SlaCap
     {
@@ -405,6 +408,7 @@ private:
     mutable GLGizmosManager m_gizmos;
     mutable GLToolbar m_toolbar;
     ClippingPlane m_clipping_planes[2];
+    mutable ClippingPlane m_camera_clipping_plane;
     bool m_use_clipping_planes;
     mutable SlaCap m_sla_caps[2];
     std::string m_sidebar_field;
diff --git a/src/slic3r/GUI/GUI_Preview.cpp b/src/slic3r/GUI/GUI_Preview.cpp
index 438e9d236..206253451 100644
--- a/src/slic3r/GUI/GUI_Preview.cpp
+++ b/src/slic3r/GUI/GUI_Preview.cpp
@@ -818,8 +818,8 @@ void Preview::on_sliders_scroll_changed(wxEvent& event)
         }
         else if (tech == ptSLA)
         {
-            m_canvas->set_clipping_plane(0, GLCanvas3D::ClippingPlane(Vec3d::UnitZ(), -m_slider->GetLowerValueD()));
-            m_canvas->set_clipping_plane(1, GLCanvas3D::ClippingPlane(-Vec3d::UnitZ(), m_slider->GetHigherValueD()));
+            m_canvas->set_clipping_plane(0, ClippingPlane(Vec3d::UnitZ(), -m_slider->GetLowerValueD()));
+            m_canvas->set_clipping_plane(1, ClippingPlane(-Vec3d::UnitZ(), m_slider->GetHigherValueD()));
             m_canvas->set_use_clipping_planes(m_slider->GetHigherValue() != 0);
             m_canvas_widget->Refresh();
         }
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
index 74c6faa85..129db2715 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
@@ -10,6 +10,7 @@
 #include "slic3r/GUI/GUI_ObjectSettings.hpp"
 #include "slic3r/GUI/GUI_ObjectList.hpp"
 #include "slic3r/GUI/PresetBundle.hpp"
+#include "libslic3r/Tesselate.hpp"
 
 
 namespace Slic3r {
@@ -55,6 +56,11 @@ void GLGizmoSlaSupports::set_sla_support_data(ModelObject* model_object, const S
 
     if (model_object && selection.is_from_single_instance())
     {
+        // Cache the bb - it's needed for dealing with the clipping plane quite often
+        // It could be done inside update_mesh but one has to account for scaling of the instance.
+        //FIXME calling ModelObject::instance_bounding_box() is expensive!
+        m_active_instance_bb_radius = m_model_object->instance_bounding_box(m_active_instance).radius();
+
         if (is_mesh_update_necessary()) {
             update_mesh();
             editing_mode_reload_cache();
@@ -83,12 +89,75 @@ void GLGizmoSlaSupports::on_render(const Selection& selection) const
     glsafe(::glEnable(GL_BLEND));
     glsafe(::glEnable(GL_DEPTH_TEST));
 
-    render_points(selection, false);
+    // we'll recover current look direction from the modelview matrix (in world coords):
+    Eigen::Matrix<double, 4, 4, Eigen::DontAlign> modelview_matrix;
+    ::glGetDoublev(GL_MODELVIEW_MATRIX, modelview_matrix.data());
+    Vec3d direction_to_camera(modelview_matrix.data()[2], modelview_matrix.data()[6], modelview_matrix.data()[10]);
+    m_z_shift = selection.get_volume(*selection.get_volume_idxs().begin())->get_sla_shift_z();
+
+    if (m_quadric != nullptr && selection.is_from_single_instance())
+        render_points(selection, direction_to_camera, false);
+
     render_selection_rectangle();
+    render_clipping_plane(selection, direction_to_camera);
 
     glsafe(::glDisable(GL_BLEND));
 }
 
+
+
+void GLGizmoSlaSupports::render_clipping_plane(const Selection& selection, const Vec3d& direction_to_camera) const
+{
+    if (m_clipping_plane_distance == 0.f)
+        return;
+
+    const GLVolume* vol = selection.get_volume(*selection.get_volume_idxs().begin());
+    Transform3f instance_matrix = vol->get_instance_transformation().get_matrix().cast<float>();
+    Transform3f instance_matrix_no_translation_no_scaling = vol->get_instance_transformation().get_matrix(true,false,true).cast<float>();
+    Vec3f scaling = vol->get_instance_scaling_factor().cast<float>();
+
+    Vec3f up_noscale = instance_matrix_no_translation_no_scaling.inverse() * direction_to_camera.cast<float>();
+    Vec3f up = Vec3f(up_noscale(0)*scaling(0), up_noscale(1)*scaling(1), up_noscale(2)*scaling(2));
+    float height_mesh = (m_active_instance_bb_radius - m_clipping_plane_distance * 2*m_active_instance_bb_radius) * (up_noscale.norm()/up.norm());
+
+    if (m_clipping_plane_distance != m_old_clipping_plane_distance
+     || m_old_direction_to_camera != direction_to_camera) {
+
+        std::vector<ExPolygons> list_of_expolys;
+        if (! m_tms) {
+            m_tms.reset(new TriangleMeshSlicer);
+            m_tms->init(const_cast<TriangleMesh*>(&m_mesh), [](){});
+        }
+
+        m_tms->set_up_direction(up);
+        m_tms->slice(std::vector<float>{height_mesh}, 0.f, &list_of_expolys, [](){});
+        m_triangles = triangulate_expolygons_2f(list_of_expolys[0]);
+
+        m_old_direction_to_camera = direction_to_camera;
+        m_old_clipping_plane_distance = m_clipping_plane_distance;
+    }
+
+	if (! m_triangles.empty()) {
+		::glPushMatrix();
+		::glTranslated(0.0, 0.0, m_z_shift);
+		::glMultMatrixf(instance_matrix.data());
+		Eigen::Quaternionf q;
+		q.setFromTwoVectors(Vec3f::UnitZ(), up);
+		Eigen::AngleAxisf aa(q);
+		::glRotatef(aa.angle() * (180./M_PI), aa.axis()(0), aa.axis()(1), aa.axis()(2));
+		::glTranslatef(0.f, 0.f, -0.001f); // to make sure the cut is safely beyond the near clipping plane
+		::glColor3f(1.0f, 0.37f, 0.0f);
+        ::glBegin(GL_TRIANGLES);
+        ::glColor3f(1.0f, 0.37f, 0.0f);
+        for (const Vec2f& point : m_triangles)
+            ::glVertex3f(point(0), point(1), height_mesh);
+        ::glEnd();
+		::glPopMatrix();
+	}
+}
+
+
+
 void GLGizmoSlaSupports::render_selection_rectangle() const
 {
     if (m_selection_rectangle_status == srOff)
@@ -138,24 +207,25 @@ void GLGizmoSlaSupports::on_render_for_picking(const Selection& selection) const
 {
     glsafe(::glEnable(GL_DEPTH_TEST));
 
-    render_points(selection, true);
+    // we'll recover current look direction from the modelview matrix (in world coords):
+    Eigen::Matrix<double, 4, 4, Eigen::DontAlign> modelview_matrix;
+    ::glGetDoublev(GL_MODELVIEW_MATRIX, modelview_matrix.data());
+    Vec3d direction_to_camera(modelview_matrix.data()[2], modelview_matrix.data()[6], modelview_matrix.data()[10]);
+
+    render_points(selection, direction_to_camera, true);
 }
 
-void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking) const
+void GLGizmoSlaSupports::render_points(const Selection& selection, const Vec3d& direction_to_camera, bool picking) const
 {
-    if (m_quadric == nullptr || !selection.is_from_single_instance())
-        return;
-
     if (!picking)
         glsafe(::glEnable(GL_LIGHTING));
 
     const GLVolume* vol = selection.get_volume(*selection.get_volume_idxs().begin());
-    double z_shift = vol->get_sla_shift_z();
     const Transform3d& instance_scaling_matrix_inverse = vol->get_instance_transformation().get_matrix(true, true, false, true).inverse();
     const Transform3d& instance_matrix = vol->get_instance_transformation().get_matrix();
 
     glsafe(::glPushMatrix());
-    glsafe(::glTranslated(0.0, 0.0, z_shift));
+    glsafe(::glTranslated(0.0, 0.0, m_z_shift));
     glsafe(::glMultMatrixd(instance_matrix.data()));
 
     float render_color[3];
@@ -164,6 +234,9 @@ void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking)
         const sla::SupportPoint& support_point = m_editing_mode_cache[i].support_point;
         const bool& point_selected = m_editing_mode_cache[i].selected;
 
+        if (is_point_clipped(support_point.pos.cast<double>(), direction_to_camera))
+            continue;
+
         // First decide about the color of the point.
         if (picking) {
             std::array<float, 3> color = picking_color_component(i);
@@ -233,6 +306,21 @@ void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking)
     glsafe(::glPopMatrix());
 }
 
+
+
+bool GLGizmoSlaSupports::is_point_clipped(const Vec3d& point, const Vec3d& direction_to_camera) const
+{
+    if (m_clipping_plane_distance == 0.f)
+        return false;
+
+    Vec3d transformed_point = m_model_object->instances.front()->get_transformation().get_matrix() * point;
+    transformed_point(2) += m_z_shift;
+    return direction_to_camera.dot(m_model_object->instances[m_active_instance]->get_offset() + Vec3d(0., 0., m_z_shift)) + m_active_instance_bb_radius
+            - m_clipping_plane_distance * 2*m_active_instance_bb_radius < direction_to_camera.dot(transformed_point);
+}
+
+
+
 bool GLGizmoSlaSupports::is_mesh_update_necessary() const
 {
     return ((m_state == On) && (m_model_object != nullptr) && !m_model_object->instances.empty())
@@ -244,10 +332,9 @@ void GLGizmoSlaSupports::update_mesh()
     wxBusyCursor wait;
     Eigen::MatrixXf& V = m_V;
     Eigen::MatrixXi& F = m_F;
-    // Composite mesh of all instances in the world coordinate system.
     // This mesh does not account for the possible Z up SLA offset.
-    TriangleMesh mesh = m_model_object->raw_mesh();
-    const stl_file& stl = mesh.stl;
+    m_mesh = m_model_object->raw_mesh();
+    const stl_file& stl = m_mesh.stl;
     V.resize(3 * stl.stats.number_of_facets, 3);
     F.resize(stl.stats.number_of_facets, 3);
     for (unsigned int i=0; i<stl.stats.number_of_facets; ++i) {
@@ -266,6 +353,8 @@ void GLGizmoSlaSupports::update_mesh()
     m_AABB.init(m_V, m_F);
 }
 
+// Unprojects the mouse position on the mesh and return the hit point and normal of the facet.
+// The function throws if no intersection if found.
 std::pair<Vec3f, Vec3f> GLGizmoSlaSupports::unproject_on_mesh(const Vec2d& mouse_pos)
 {
     // if the gizmo doesn't have the V, F structures for igl, calculate them first:
@@ -282,31 +371,53 @@ std::pair<Vec3f, Vec3f> GLGizmoSlaSupports::unproject_on_mesh(const Vec2d& mouse
     ::gluUnProject(mouse_pos(0), viewport[3] - mouse_pos(1), 0.f, modelview_matrix.data(), projection_matrix.data(), viewport.data(), &point1(0), &point1(1), &point1(2));
     ::gluUnProject(mouse_pos(0), viewport[3] - mouse_pos(1), 1.f, modelview_matrix.data(), projection_matrix.data(), viewport.data(), &point2(0), &point2(1), &point2(2));
 
-    igl::Hit hit;
+    std::vector<igl::Hit> hits;
 
     const Selection& selection = m_parent.get_selection();
     const GLVolume* volume = selection.get_volume(*selection.get_volume_idxs().begin());
-    double z_offset = volume->get_sla_shift_z();
 
-    point1(2) -= z_offset;
-	point2(2) -= z_offset;
+    // we'll recover current look direction from the modelview matrix (in world coords):
+    Vec3d direction_to_camera(modelview_matrix.data()[2], modelview_matrix.data()[6], modelview_matrix.data()[10]);
+
+    point1(2) -= m_z_shift;
+	point2(2) -= m_z_shift;
 
     Transform3d inv = volume->get_instance_transformation().get_matrix().inverse();
 
     point1 = inv * point1;
     point2 = inv * point2;
 
-    if (!m_AABB.intersect_ray(m_V, m_F, point1.cast<float>(), (point2-point1).cast<float>(), hit))
+    if (!m_AABB.intersect_ray(m_V, m_F, point1.cast<float>(), (point2-point1).cast<float>(), hits))
         throw std::invalid_argument("unproject_on_mesh(): No intersection found.");
 
-    int fid = hit.id;   // facet id
-    Vec3f bc(1-hit.u-hit.v, hit.u, hit.v); // barycentric coordinates of the hit
-    Vec3f a = (m_V.row(m_F(fid, 1)) - m_V.row(m_F(fid, 0)));
-    Vec3f b = (m_V.row(m_F(fid, 2)) - m_V.row(m_F(fid, 0)));
+    std::sort(hits.begin(), hits.end(), [](const igl::Hit& a, const igl::Hit& b) { return a.t < b.t; });
+
+    // Now let's iterate through the points and find the first that is not clipped:
+    unsigned int i=0;
+    Vec3f bc;
+    Vec3f a;
+    Vec3f b;
+    Vec3f result;
+    for (i=0; i<hits.size(); ++i) {
+        igl::Hit& hit = hits[i];
+        int fid = hit.id;   // facet id
+        bc = Vec3f(1-hit.u-hit.v, hit.u, hit.v); // barycentric coordinates of the hit
+        a = (m_V.row(m_F(fid, 1)) - m_V.row(m_F(fid, 0)));
+        b = (m_V.row(m_F(fid, 2)) - m_V.row(m_F(fid, 0)));
+        result = bc(0) * m_V.row(m_F(fid, 0)) + bc(1) * m_V.row(m_F(fid, 1)) + bc(2)*m_V.row(m_F(fid, 2));
+        if (m_clipping_plane_distance == 0.f || !is_point_clipped(result.cast<double>(), direction_to_camera))
+            break;
+    }
+
+    if (i==hits.size() || (hits.size()-i) % 2 != 0) {
+        // All hits are either clipped, or there is an odd number of unclipped
+        // hits - meaning the nearest must be from inside the mesh.
+        throw std::invalid_argument("unproject_on_mesh(): No intersection found.");
+    }
 
     // Calculate and return both the point and the facet normal.
     return std::make_pair(
-            bc(0) * m_V.row(m_F(fid, 0)) + bc(1) * m_V.row(m_F(fid, 1)) + bc(2)*m_V.row(m_F(fid, 2)),
+            result,
             a.cross(b)
         );
 }
@@ -377,36 +488,64 @@ bool GLGizmoSlaSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
 
             const Selection& selection = m_parent.get_selection();
             const GLVolume* volume = selection.get_volume(*selection.get_volume_idxs().begin());
-            double z_offset = volume->get_sla_shift_z();
 
             // bounding box created from the rectangle corners - will take care of order of the corners
             BoundingBox rectangle(Points{Point(m_selection_rectangle_start_corner.cast<int>()), Point(m_selection_rectangle_end_corner.cast<int>())});
 
-            const Transform3d& instance_matrix_no_translation = volume->get_instance_transformation().get_matrix(true);
+            const Transform3d& instance_matrix_no_translation_no_scaling = volume->get_instance_transformation().get_matrix(true,false,true);
+
             // we'll recover current look direction from the modelview matrix (in world coords)...
             Vec3f direction_to_camera = camera.get_dir_forward().cast<float>();
             // ...and transform it to model coords.
-            direction_to_camera = (instance_matrix_no_translation.inverse().cast<float>() * direction_to_camera).normalized().eval();
+            Vec3f direction_to_camera_mesh = (instance_matrix_no_translation_no_scaling.inverse().cast<float>() * direction_to_camera).normalized().eval();
+            Vec3f scaling = volume->get_instance_scaling_factor().cast<float>();
+            direction_to_camera_mesh = Vec3f(direction_to_camera_mesh(0)*scaling(0), direction_to_camera_mesh(1)*scaling(1), direction_to_camera_mesh(2)*scaling(2));
 
             // Iterate over all points, check if they're in the rectangle and if so, check that they are not obscured by the mesh:
             for (unsigned int i=0; i<m_editing_mode_cache.size(); ++i) {
                 const sla::SupportPoint &support_point = m_editing_mode_cache[i].support_point;
                 Vec3f pos = instance_matrix.cast<float>() * support_point.pos;
-                pos(2) += z_offset;
+                pos(2) += m_z_shift;
                   GLdouble out_x, out_y, out_z;
                   ::gluProject((GLdouble)pos(0), (GLdouble)pos(1), (GLdouble)pos(2), (GLdouble*)modelview_matrix.data(), (GLdouble*)projection_matrix.data(), (GLint*)viewport.data(), &out_x, &out_y, &out_z);
                   out_y = m_canvas_height - out_y;
 
-                if (rectangle.contains(Point(out_x, out_y))) {
+                if (rectangle.contains(Point(out_x, out_y)) && !is_point_clipped(support_point.pos.cast<double>(), direction_to_camera.cast<double>())) {
                     bool is_obscured = false;
                     // Cast a ray in the direction of the camera and look for intersection with the mesh:
                     std::vector<igl::Hit> hits;
                     // Offset the start of the ray to the front of the ball + EPSILON to account for numerical inaccuracies.
-                    if (m_AABB.intersect_ray(m_V, m_F, support_point.pos + direction_to_camera * (support_point.head_front_radius + EPSILON), direction_to_camera, hits))
+                    if (m_AABB.intersect_ray(m_V, m_F, support_point.pos + direction_to_camera_mesh * (support_point.head_front_radius + EPSILON), direction_to_camera_mesh, hits)) {
+                        std::sort(hits.begin(), hits.end(), [](const igl::Hit& h1, const igl::Hit& h2) { return h1.t < h2.t; });
+
+                        if (m_clipping_plane_distance != 0.f) {
+                            // If the closest hit facet normal points in the same direction as the ray,
+                            // we are looking through the mesh and should therefore discard the point:
+                            int fid = hits.front().id;   // facet id
+                            Vec3f a = (m_V.row(m_F(fid, 1)) - m_V.row(m_F(fid, 0)));
+                            Vec3f b = (m_V.row(m_F(fid, 2)) - m_V.row(m_F(fid, 0)));
+                            if ((a.cross(b)).dot(direction_to_camera_mesh) > 0.f)
+                                is_obscured = true;
+
+                            // Eradicate all hits that are on clipped surfaces:
+                            for (unsigned int j=0; j<hits.size(); ++j) {
+                                const igl::Hit& hit = hits[j];
+                                int fid = hit.id;   // facet id
+
+                                Vec3f bc = Vec3f(1-hit.u-hit.v, hit.u, hit.v); // barycentric coordinates of the hit
+                                Vec3f hit_pos = bc(0) * m_V.row(m_F(fid, 0)) + bc(1) * m_V.row(m_F(fid, 1)) + bc(2)*m_V.row(m_F(fid, 2));
+                                if (is_point_clipped(hit_pos.cast<double>(), direction_to_camera.cast<double>())) {
+                                    hits.erase(hits.begin()+j);
+                                    --j;
+                                }
+                            }
+                        }
+
                         // FIXME: the intersection could in theory be behind the camera, but as of now we only have camera direction.
                         // Also, the threshold is in mesh coordinates, not in actual dimensions.
-                        if (hits.size() > 1 || hits.front().t > 0.001f)
+                        if (!hits.empty())
                             is_obscured = true;
+                    }
 
                     if (!is_obscured) {
                         if (m_selection_rectangle_status == srDeselect)
@@ -564,6 +703,64 @@ void GLGizmoSlaSupports::update_cache_entry_normal(unsigned int i) const
 
 
 
+
+ClippingPlane GLGizmoSlaSupports::get_sla_clipping_plane() const
+{
+    if (!m_model_object)
+        return ClippingPlane::ClipsNothing();
+
+    Eigen::Matrix<GLdouble, 4, 4, Eigen::DontAlign> modelview_matrix;
+    ::glGetDoublev(GL_MODELVIEW_MATRIX, modelview_matrix.data());
+
+    // we'll recover current look direction from the modelview matrix (in world coords):
+    Vec3d direction_to_camera(modelview_matrix.data()[2], modelview_matrix.data()[6], modelview_matrix.data()[10]);
+    float dist = direction_to_camera.dot(m_model_object->instances[m_active_instance]->get_offset() + Vec3d(0., 0., m_z_shift));
+
+    return ClippingPlane(-direction_to_camera.normalized(),(dist - (-m_active_instance_bb_radius) - m_clipping_plane_distance * 2*m_active_instance_bb_radius));
+}
+
+
+/*
+void GLGizmoSlaSupports::find_intersecting_facets(const igl::AABB<Eigen::MatrixXf, 3>* aabb, const Vec3f& normal, double offset, std::vector<unsigned int>& idxs) const
+{
+    if (aabb->is_leaf()) { // this is a facet
+        // corner.dot(normal) - offset
+        idxs.push_back(aabb->m_primitive);
+    }
+    else { // not a leaf
+    using CornerType = Eigen::AlignedBox<float, 3>::CornerType;
+        bool sign = std::signbit(offset - normal.dot(aabb->m_box.corner(CornerType(0))));
+        for (unsigned int i=1; i<8; ++i)
+            if (std::signbit(offset - normal.dot(aabb->m_box.corner(CornerType(i)))) != sign) {
+                find_intersecting_facets(aabb->m_left, normal, offset, idxs);
+                find_intersecting_facets(aabb->m_right, normal, offset, idxs);
+            }
+    }
+}
+
+
+
+void GLGizmoSlaSupports::make_line_segments() const
+{
+    TriangleMeshSlicer tms(&m_model_object->volumes.front()->mesh);
+    Vec3f normal(0.f, 1.f, 1.f);
+    double d = 0.;
+
+    std::vector<IntersectionLine> lines;
+    find_intersections(&m_AABB, normal, d, lines);
+    ExPolygons expolys;
+    tms.make_expolygons_simple(lines, &expolys);
+
+    SVG svg("slice_loops.svg", get_extents(expolys));
+    svg.draw(expolys);
+    //for (const IntersectionLine &l : lines[i])
+    //    svg.draw(l, "red", 0);
+    //svg.draw_outline(expolygons, "black", "blue", 0);
+    svg.Close();
+}
+*/
+
+
 void GLGizmoSlaSupports::on_render_input_window(float x, float y, float bottom_limit, const Selection& selection)
 {
     if (!m_model_object)
@@ -681,6 +878,13 @@ RENDER_AGAIN:
                      (m_model_object->sla_points_status == sla::PointsStatus::Generating ? "Generation in progress..." : "UNKNOWN STATUS"))));
     }
 
+
+    // Following is rendered in both editing and non-editing mode:
+    m_imgui->text("Clipping of view: ");
+    ImGui::SameLine();
+    ImGui::PushItemWidth(150.0f);
+    bool value_changed = ImGui::SliderFloat("  ", &m_clipping_plane_distance, 0.f, 1.f, "%.2f");
+    
     m_imgui->end();
 
     if (m_editing_mode != m_old_editing_state) { // user toggled between editing/non-editing mode
@@ -752,8 +956,8 @@ void GLGizmoSlaSupports::on_set_state()
             m_new_point_head_diameter = static_cast<const ConfigOptionFloat*>(cfg.option("support_head_front_diameter"))->value;
         }
         if (m_state == Off && m_old_state != Off) { // the gizmo was just turned Off
-        wxGetApp().CallAfter([this]() {
-               // Following is called through CallAfter, because otherwise there was a problem
+            wxGetApp().CallAfter([this]() {
+                // Following is called through CallAfter, because otherwise there was a problem
                 // on OSX with the wxMessageDialog being shown several times when clicked into.
                 if (m_model_object) {
                     if (m_unsaved_changes) {
@@ -765,10 +969,16 @@ void GLGizmoSlaSupports::on_set_state()
                             editing_mode_discard_changes();
                     }
                 }
-
                 m_parent.toggle_model_objects_visibility(true);
                 m_editing_mode = false; // so it is not active next time the gizmo opens
                 m_editing_mode_cache.clear();
+                m_clipping_plane_distance = 0.f;
+                // Release copy of the mesh, triangle slicer and the AABB spatial search structure.
+				m_mesh.clear();
+                m_AABB.deinit();
+				m_V = Eigen::MatrixXf();
+				m_F = Eigen::MatrixXi();
+                m_tms.reset(nullptr);
             });
         }
         m_old_state = m_state;
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp
index 0b66ed529..c74559e2f 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp
@@ -17,12 +17,17 @@ namespace Slic3r {
 namespace GUI {
 
 
+class ClippingPlane;
+
+
 class GLGizmoSlaSupports : public GLGizmoBase
 {
 private:
     ModelObject* m_model_object = nullptr;
     ModelID m_current_mesh_model_id = 0;
     int m_active_instance = -1;
+    float m_active_instance_bb_radius; // to cache the bb
+    mutable float m_z_shift = 0.f;
     std::pair<Vec3f, Vec3f> unproject_on_mesh(const Vec2d& mouse_pos);
 
     const float RenderPointScale = 1.f;
@@ -31,6 +36,8 @@ private:
     Eigen::MatrixXf m_V; // vertices
     Eigen::MatrixXi m_F; // facets indices
     igl::AABB<Eigen::MatrixXf,3> m_AABB;
+    TriangleMesh m_mesh;
+    mutable std::vector<Vec2f> m_triangles;
 
     class CacheEntry {
     public:
@@ -52,7 +59,7 @@ public:
     void set_sla_support_data(ModelObject* model_object, const Selection& selection);
     bool gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_position, bool shift_down, bool alt_down, bool control_down);
     void delete_selected_points(bool force = false);
-    std::pair<float, float> get_sla_clipping_plane() const;
+    ClippingPlane get_sla_clipping_plane() const;
 
 private:
     bool on_init();
@@ -61,7 +68,8 @@ private:
     virtual void on_render_for_picking(const Selection& selection) const;
 
     void render_selection_rectangle() const;
-    void render_points(const Selection& selection, bool picking = false) const;
+    void render_points(const Selection& selection, const Vec3d& direction_to_camera, bool picking = false) const;
+    void render_clipping_plane(const Selection& selection, const Vec3d& direction_to_camera) const;
     bool is_mesh_update_necessary() const;
     void update_mesh();
     void update_cache_entry_normal(unsigned int i) const;
@@ -74,6 +82,8 @@ private:
     float m_density = 100.f;
     mutable std::vector<CacheEntry> m_editing_mode_cache; // a support point and whether it is currently selected
     float m_clipping_plane_distance = 0.f;
+    mutable float m_old_clipping_plane_distance = 0.f;
+    mutable Vec3d m_old_direction_to_camera;
 
     enum SelectionRectangleStatus {
         srOff = 0,
@@ -90,7 +100,11 @@ private:
     int m_canvas_width;
     int m_canvas_height;
 
+    mutable std::unique_ptr<TriangleMeshSlicer> m_tms;
+
     std::vector<const ConfigOption*> get_config_options(const std::vector<std::string>& keys) const;
+    bool is_point_clipped(const Vec3d& point, const Vec3d& direction_to_camera) const;
+    void find_intersecting_facets(const igl::AABB<Eigen::MatrixXf, 3>* aabb, const Vec3f& normal, double offset, std::vector<unsigned int>& out) const;
 
     // Methods that do the model_object and editing cache synchronization,
     // editing mode selection, etc:
diff --git a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
index d00f3440a..cb2d6faed 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
@@ -467,6 +467,19 @@ bool GLGizmosManager::gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_p
     return false;
 }
 
+ClippingPlane GLGizmosManager::get_sla_clipping_plane() const
+{
+    if (!m_enabled || m_current != SlaSupports)
+        return ClippingPlane::ClipsNothing();
+
+    GizmosMap::const_iterator it = m_gizmos.find(SlaSupports);
+    if (it != m_gizmos.end())
+        return reinterpret_cast<GLGizmoSlaSupports*>(it->second)->get_sla_clipping_plane();
+
+    return ClippingPlane::ClipsNothing();
+}
+
+
 void GLGizmosManager::render_current_gizmo(const Selection& selection) const
 {
     if (!m_enabled)
diff --git a/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp b/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp
index 16e902522..f7a1a980e 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmosManager.hpp
@@ -13,6 +13,7 @@ namespace GUI {
 class Selection;
 class GLGizmoBase;
 class GLCanvas3D;
+class ClippingPlane;
 
 class Rect
 {
@@ -146,7 +147,7 @@ public:
 
     void set_sla_support_data(ModelObject* model_object, const Selection& selection);
     bool gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_position = Vec2d::Zero(), bool shift_down = false, bool alt_down = false, bool control_down = false);
-
+    ClippingPlane get_sla_clipping_plane() const;
 
     void render_current_gizmo(const Selection& selection) const;
     void render_current_gizmo_for_picking_pass(const Selection& selection) const;
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index a34562d85..027db69f5 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -3711,6 +3711,7 @@ void Plater::paste_from_clipboard()
 {
     p->view3D->get_canvas3d()->get_selection().paste_from_clipboard();
 }
+
 bool Plater::can_paste_from_clipboard() const
 {
     const Selection& selection = p->view3D->get_canvas3d()->get_selection();
diff --git a/src/slic3r/GUI/Selection.cpp b/src/slic3r/GUI/Selection.cpp
index 41313d5ed..315aa487a 100644
--- a/src/slic3r/GUI/Selection.cpp
+++ b/src/slic3r/GUI/Selection.cpp
@@ -1079,6 +1079,7 @@ void Selection::paste_from_clipboard()
     case Instance:
     {
         paste_objects_from_clipboard();
+
         break;
     }
     }
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index c735a40ee..30e3bfe89 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -3224,7 +3224,8 @@ void TabSLAMaterial::build()
     optgroup = page->new_optgroup(_(L("Corrections")));
     optgroup->label_width = 19 * m_em_unit;//190;
     std::vector<std::string> corrections = {"material_correction"};
-    std::vector<std::string> axes{ "X", "Y", "Z" };
+//    std::vector<std::string> axes{ "X", "Y", "Z" };
+    std::vector<std::string> axes{ "XY", "Z" };
     for (auto& opt_key : corrections) {
         auto line = Line{ m_config->def()->get(opt_key)->full_label, "" };
         int id = 0;