diff --git a/src/libslic3r/SLA/SLABasePool.cpp b/src/libslic3r/SLA/SLABasePool.cpp
index fe31ed57dc..91f8441606 100644
--- a/src/libslic3r/SLA/SLABasePool.cpp
+++ b/src/libslic3r/SLA/SLABasePool.cpp
@@ -425,6 +425,8 @@ void base_plate(const TriangleMesh &mesh, ExPolygons &output, float h)
 
     TriangleMesh upper, lower;
     slicer.cut(h, &upper, &lower);
+
+    // TODO: this might be slow
     output = lower.horizontal_projection();
 
     for(auto& o : output) o = o.simplify(0.1/SCALING_FACTOR).front();
diff --git a/src/libslic3r/SLA/SLASupportTree.cpp b/src/libslic3r/SLA/SLASupportTree.cpp
index d689324c06..9bb590d303 100644
--- a/src/libslic3r/SLA/SLASupportTree.cpp
+++ b/src/libslic3r/SLA/SLASupportTree.cpp
@@ -168,9 +168,10 @@ Contour3D sphere(double rho, Portion portion = make_portion(0.0, 2.0*PI),
     return ret;
 }
 
-Contour3D cylinder(double r, double h, size_t steps) {
+Contour3D cylinder(double r, double h, size_t ssteps) {
     Contour3D ret;
 
+    auto steps = int(ssteps);
     auto& points = ret.points;
     auto& indices = ret.indices;
     points.reserve(2*steps);
@@ -275,10 +276,10 @@ struct Head {
             mesh.indices.emplace_back(i1s1, i2s2, i1s2);
         }
 
-        auto i1s1 = coord_t(s1.points.size()) - steps;
+        auto i1s1 = coord_t(s1.points.size()) - coord_t(steps);
         auto i2s1 = coord_t(s1.points.size()) - 1;
         auto i1s2 = coord_t(s1.points.size());
-        auto i2s2 = coord_t(s1.points.size()) + steps - 1;
+        auto i2s2 = coord_t(s1.points.size()) + coord_t(steps) - 1;
 
         mesh.indices.emplace_back(i2s2, i2s1, i1s1);
         mesh.indices.emplace_back(i1s2, i2s2, i1s1);
@@ -368,13 +369,13 @@ struct Pillar {
         }
 
         indices.reserve(2*steps);
-        auto offs = steps;
+        int offs = int(steps);
         for(int i = 0; i < steps - 1; ++i) {
             indices.emplace_back(i, i + offs, offs + i + 1);
             indices.emplace_back(i, offs + i + 1, i + 1);
         }
 
-        auto last = steps - 1;
+        int last = int(steps) - 1;
         indices.emplace_back(0, last, offs);
         indices.emplace_back(last, offs + last, offs);
     }
@@ -499,6 +500,27 @@ struct CompactBridge {
     }
 };
 
+// A wrapper struct around the base pool (pad)
+struct Pad {
+//    Contour3D mesh;
+    TriangleMesh tmesh;
+    PoolConfig cfg;
+    double zlevel;
+
+    Pad() {}
+
+    Pad(const TriangleMesh& object_support_mesh,
+        double ground_level,
+        const PoolConfig& cfg) : zlevel(ground_level)
+    {
+        ExPolygons basep;
+        base_plate(object_support_mesh, basep);
+        create_base_pool(basep, tmesh, cfg);
+        tmesh.translate(0, 0, float(zlevel));
+        std::cout << "pad ground level " << zlevel << std::endl;
+    }
+};
+
 EigenMesh3D to_eigenmesh(const Contour3D& cntr) {
     EigenMesh3D emesh;
 
@@ -564,7 +586,11 @@ EigenMesh3D to_eigenmesh(const TriangleMesh& tmesh) {
 }
 
 EigenMesh3D to_eigenmesh(const ModelObject& modelobj) {
-    return to_eigenmesh(modelobj.raw_mesh());
+    auto&& rmesh = modelobj.raw_mesh();
+    auto&& ret = to_eigenmesh(rmesh);
+    auto&& bb = rmesh.bounding_box();
+    ret.ground_level = bb.min(Z);
+    return ret;
 }
 
 EigenMesh3D to_eigenmesh(const Model& model) {
@@ -606,13 +632,12 @@ PointSet support_points(const Model& model) {
     return ret;
 }
 
-PointSet support_points(const ModelObject& modelobject, std::size_t instance_id)
+PointSet support_points(const ModelObject& modelobject)
 {
     PointSet ret(modelobject.sla_support_points.size(), 3);
     long i = 0;
-    ModelInstance *inst = modelobject.instances[instance_id];
     for(const Vec3f& msource : modelobject.sla_support_points) {
-        ret.row(i++) = model_coord(*inst, msource);
+        ret.row(i++) = msource.cast<double>();
     }
     return ret;
 }
@@ -643,12 +668,16 @@ class SLASupportTree::Impl {
     std::vector<Junction> m_junctions;
     std::vector<Bridge> m_bridges;
     std::vector<CompactBridge> m_compact_bridges;
+    Pad m_pad;
+    mutable TriangleMesh meshcache; mutable bool meshcache_valid;
+    mutable double model_height = 0; // the full height of the model
 public:
-    float model_height = 0; // the full height of the model
+    double ground_level = 0;
 
     template<class...Args> Head& add_head(Args&&... args) {
         m_heads.emplace_back(std::forward<Args>(args)...);
         m_heads.back().id = long(m_heads.size() - 1);
+        meshcache_valid = false;
         return m_heads.back();
     }
 
@@ -661,6 +690,7 @@ public:
         head.pillar_id = pillar.id;
         pillar.start_junction_id = head.id;
         pillar.starts_from_head = true;
+        meshcache_valid = false;
         return m_pillars.back();
     }
 
@@ -669,6 +699,7 @@ public:
         Pillar& p = m_pillars[pillar_id];
         assert(p.starts_from_head && p.start_junction_id > 0 &&
                p.start_junction_id < m_heads.size() );
+        meshcache_valid = false;
         return m_heads[p.start_junction_id];
     }
 
@@ -676,18 +707,21 @@ public:
         assert(headid >= 0 && headid < m_heads.size());
         Head& h = m_heads[headid];
         assert(h.pillar_id > 0 && h.pillar_id < m_pillars.size());
+        meshcache_valid = false;
         return m_pillars[h.pillar_id];
     }
 
     template<class...Args> const Junction& add_junction(Args&&... args) {
         m_junctions.emplace_back(std::forward<Args>(args)...);
         m_junctions.back().id = long(m_junctions.size() - 1);
+        meshcache_valid = false;
         return m_junctions.back();
     }
 
     template<class...Args> const Bridge& add_bridge(Args&&... args) {
         m_bridges.emplace_back(std::forward<Args>(args)...);
         m_bridges.back().id = long(m_bridges.size() - 1);
+        meshcache_valid = false;
         return m_bridges.back();
     }
 
@@ -695,17 +729,64 @@ public:
     const CompactBridge& add_compact_bridge(Args&&...args) {
         m_compact_bridges.emplace_back(std::forward<Args>(args)...);
         m_compact_bridges.back().id = long(m_compact_bridges.size() - 1);
+        meshcache_valid = false;
         return m_compact_bridges.back();
     }
 
     const std::vector<Head>& heads() const { return m_heads; }
-    Head& head(size_t idx) { return m_heads[idx]; }
+    Head& head(size_t idx) { meshcache_valid = false; return m_heads[idx]; }
     const std::vector<Pillar>& pillars() const { return m_pillars; }
     const std::vector<Bridge>& bridges() const { return m_bridges; }
     const std::vector<Junction>& junctions() const { return m_junctions; }
     const std::vector<CompactBridge>& compact_bridges() const {
         return m_compact_bridges;
     }
+
+    const Pad& create_pad(const TriangleMesh& object_supports,
+                          const PoolConfig& cfg) {
+        m_pad = Pad(object_supports, ground_level, cfg);
+        return m_pad;
+    }
+
+    const Pad& pad() const { return m_pad; }
+
+    // WITHOUT THE PAD!!!
+    const TriangleMesh& merged_mesh() const {
+        if(meshcache_valid) return meshcache;
+
+        meshcache = TriangleMesh();
+
+        for(auto& head : heads()) {
+            meshcache.merge(mesh(head.mesh));
+        }
+
+        for(auto& stick : pillars()) {
+            meshcache.merge(mesh(stick.mesh));
+            meshcache.merge(mesh(stick.base));
+        }
+
+        for(auto& j : junctions()) {
+            meshcache.merge(mesh(j.mesh));
+        }
+
+        for(auto& cb : compact_bridges()) {
+            meshcache.merge(mesh(cb.mesh));
+        }
+
+        for(auto& bs : bridges()) {
+            meshcache.merge(mesh(bs.mesh));
+        }
+
+        BoundingBoxf3&& bb = meshcache.bounding_box();
+        model_height = bb.max(Z);
+
+        meshcache_valid = true;
+    }
+
+    double full_height() const {
+        if(!meshcache_valid) merged_mesh();
+        return model_height;
+    }
 };
 
 template<class DistFn>
@@ -908,6 +989,7 @@ bool SLASupportTree::generate(const PointSet &points,
     using Result = SLASupportTree::Impl;
 
     Result& result = *m_impl;
+    result.ground_level = mesh.ground_level;
 
     enum Steps {
         BEGIN,
@@ -925,9 +1007,9 @@ bool SLASupportTree::generate(const PointSet &points,
     };
 
     // Debug:
-    for(int pn = 0; pn < points.rows(); ++pn) {
-        std::cout << "p " << pn << " " << points.row(pn) << std::endl;
-    }
+    // for(int pn = 0; pn < points.rows(); ++pn) {
+    //     std::cout << "p " << pn << " " << points.row(pn) << std::endl;
+    // }
 
     auto filterfn = [] (
             const SupportConfig& cfg,
@@ -1119,8 +1201,8 @@ bool SLASupportTree::generate(const PointSet &points,
         const Head& phead = result.pillar_head(pillar.id);
         const Head& nextphead = result.pillar_head(nextpillar.id);
 
-        double d = 2*pillar.r;
-        const Vec3d& pp = pillar.endpoint.cwiseProduct(Vec3d{1, 1, 0});
+//        double d = 2*pillar.r;
+//        const Vec3d& pp = pillar.endpoint.cwiseProduct(Vec3d{1, 1, 0});
 
         Vec3d sj = phead.junction_point();
         sj(Z) = std::min(sj(Z), nextphead.junction_point()(Z));
@@ -1176,10 +1258,13 @@ bool SLASupportTree::generate(const PointSet &points,
         const double hbr = cfg.head_back_radius_mm;
         const double pradius = cfg.pillar_radius_mm;
         const double maxbridgelen = cfg.max_bridge_length_mm;
+        const double gndlvl = emesh.ground_level - cfg.object_elevation_mm;
 
         ClusterEl cl_centroids;
         cl_centroids.reserve(gnd_clusters.size());
 
+        std::cout << "gnd_clusters size: " << gnd_clusters.size() << std::endl;
+
         SpatIndex pheadindex; // spatial index for the junctions
         for(auto cl : gnd_clusters) {
             // place all the centroid head positions into the index. We will
@@ -1201,7 +1286,7 @@ bool SLASupportTree::generate(const PointSet &points,
             unsigned hid = gndidx[cl[cid]]; // Head index
             Head& h = result.head(hid);
             h.transform();
-            Vec3d p = h.junction_point(); p(Z) = 0;
+            Vec3d p = h.junction_point(); p(Z) = gndlvl;
 
             pheadindex.insert(p, hid);
         }
@@ -1218,7 +1303,7 @@ bool SLASupportTree::generate(const PointSet &points,
             auto& head = result.head(index_to_heads);
 
             Vec3d startpoint = head.junction_point();
-            auto endpoint = startpoint; endpoint(Z) = 0;
+            auto endpoint = startpoint; endpoint(Z) = gndlvl;
 
             // Create the central pillar of the cluster with its base on the
             // ground
@@ -1233,7 +1318,7 @@ bool SLASupportTree::generate(const PointSet &points,
             // is distributed more effectively on the pillar.
 
             auto search_nearest =
-                    [&cfg, &result, &emesh, maxbridgelen]
+                    [&cfg, &result, &emesh, maxbridgelen, gndlvl]
                     (SpatIndex& spindex, const Vec3d& jsh)
             {
                 long nearest_id = -1;
@@ -1244,7 +1329,7 @@ bool SLASupportTree::generate(const PointSet &points,
                     // (this may happen as the clustering is not perfect)
                     // than we will bridge to this closer pillar
 
-                    Vec3d qp(jsh(X), jsh(Y), 0);
+                    Vec3d qp(jsh(X), jsh(Y), gndlvl);
                     auto ne = spindex.nearest(qp, 1).front();
                     const Head& nearhead = result.heads()[ne.second];
 
@@ -1263,7 +1348,7 @@ bool SLASupportTree::generate(const PointSet &points,
                     }
 
                     double d = distance(jp, jn);
-                    if(jn(Z) <= 0 || d > max_len) break;
+                    if(jn(Z) <= gndlvl || d > max_len) break;
 
                     double chkd = ray_mesh_intersect(jp, dirv(jp, jn), emesh);
                     if(chkd >= d) nearest_id = ne.second;
@@ -1278,7 +1363,7 @@ bool SLASupportTree::generate(const PointSet &points,
                 sidehead.transform();
 
                 Vec3d jsh = sidehead.junction_point();
-                Vec3d jp2d = {jsh(X), jsh(Y), 0};
+//                Vec3d jp2d = {jsh(X), jsh(Y), gndlvl};
                 SpatIndex spindex = pheadindex;
                 long nearest_id = search_nearest(spindex, jsh);
 
@@ -1286,7 +1371,7 @@ bool SLASupportTree::generate(const PointSet &points,
                 // to connect the sidehead to the ground
                 if(nearest_id < 0) {
                     // Could not find a pillar, create one
-                    Vec3d jp = jsh; jp(Z) = 0;
+                    Vec3d jp = jsh; jp(Z) = gndlvl;
                     result.add_pillar(sidehead.id, jp, pradius).
                         add_base(cfg.base_height_mm, cfg.base_radius_mm);
 
@@ -1571,28 +1656,12 @@ bool SLASupportTree::generate(const PointSet &points,
 
 void SLASupportTree::merged_mesh(TriangleMesh &outmesh) const
 {
-    const SLASupportTree::Impl& stree = get();
+    outmesh.merge(get().merged_mesh());
+}
 
-    for(auto& head : stree.heads()) {
-        outmesh.merge(mesh(head.mesh));
-    }
-
-    for(auto& stick : stree.pillars()) {
-        outmesh.merge(mesh(stick.mesh));
-        outmesh.merge(mesh(stick.base));
-    }
-
-    for(auto& j : stree.junctions()) {
-        outmesh.merge(mesh(j.mesh));
-    }
-
-    for(auto& cb : stree.compact_bridges()) {
-        outmesh.merge(mesh(cb.mesh));
-    }
-
-    for(auto& bs : stree.bridges()) {
-        outmesh.merge(mesh(bs.mesh));
-    }
+void SLASupportTree::merged_mesh_with_pad(TriangleMesh &outmesh) const {
+    merged_mesh(outmesh);
+    outmesh.merge(get_pad());
 }
 
 template<class T> void slice_part(const T& inp,
@@ -1616,7 +1685,7 @@ SlicedSupports SLASupportTree::slice(float layerh, float init_layerh) const
 {
     if(init_layerh < 0) init_layerh = layerh;
     auto& stree = get();
-    const float modelh = stree.model_height;
+    const float modelh = stree.full_height();
 
     std::vector<float> heights; heights.reserve(size_t(modelh/layerh) + 1);
     for(float h = init_layerh; h <= modelh; h += layerh) {
@@ -1640,10 +1709,24 @@ SlicedSupports SLASupportTree::slice(float layerh, float init_layerh) const
     return {};
 }
 
-// Here we should implement the support editing
-void SLASupportTree::mouse_event(const MouseEvent &)
+const TriangleMesh &SLASupportTree::add_pad(double min_wall_thickness_mm,
+                                            double min_wall_height_mm,
+                                            double max_merge_distance_mm,
+                                            double edge_radius_mm) const
 {
+    TriangleMesh mm;
+    merged_mesh(mm);
+    PoolConfig pcfg;
+//    pcfg.min_wall_thickness_mm = min_wall_thickness_mm;
+//    pcfg.min_wall_height_mm    = min_wall_height_mm;
+//    pcfg.max_merge_distance_mm = max_merge_distance_mm;
+//    pcfg.edge_radius_mm        = edge_radius_mm;
+    return m_impl->create_pad(mm, pcfg).tmesh;
+}
 
+const TriangleMesh &SLASupportTree::get_pad() const
+{
+    return m_impl->pad().tmesh;
 }
 
 SLASupportTree::SLASupportTree(const Model& model,
diff --git a/src/libslic3r/SLA/SLASupportTree.hpp b/src/libslic3r/SLA/SLASupportTree.hpp
index 3a1c5ef689..9d32bcaf92 100644
--- a/src/libslic3r/SLA/SLASupportTree.hpp
+++ b/src/libslic3r/SLA/SLASupportTree.hpp
@@ -60,6 +60,10 @@ struct SupportConfig {
 
     // The max length of a bridge in mm
     double max_bridge_length_mm = 15.0;
+
+    // The elevation in Z direction upwards. This is the space between the pad
+    // and the model object's bounding box bottom.
+    double object_elevation_mm = 0;
 };
 
 /// A Control structure for the support calculation. Consists of the status
@@ -76,6 +80,7 @@ struct Controller {
 struct EigenMesh3D {
     Eigen::MatrixXd V;
     Eigen::MatrixXi F;
+    double ground_level = 0;
 
     // igl crashes with the following data types:
 //    Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic, Eigen::DontAlign> V;
@@ -100,7 +105,7 @@ EigenMesh3D to_eigenmesh(const Model& model);
 EigenMesh3D to_eigenmesh(const ModelObject& model);
 
 PointSet support_points(const Model& model);
-PointSet support_points(const ModelObject& modelobject, size_t instance_id = 0);
+PointSet support_points(const ModelObject& modelobject);
 
 /* ************************************************************************** */
 
@@ -111,24 +116,10 @@ public:
     SLASupportsStoppedException(): std::runtime_error("") {}
 };
 
-/// A simple type carrying mouse event info. For support editing purposes
-struct MouseEvent {
-    enum Buttons {
-        M_RIGHT, M_LEFT, M_MIDDLE
-    } button;
-
-    enum Type {
-        ENGAGE, RELEASE, MOVE
-    } type;
-
-    Vec3d coords;
-};
-
 /// The class containing mesh data for the generated supports.
 class SLASupportTree {
     class Impl;
     std::unique_ptr<Impl> m_impl;
-    std::function<void()> m_vcallback;
 
     Impl& get() { return *m_impl; }
     const Impl& get() const { return *m_impl; }
@@ -160,20 +151,23 @@ public:
     ~SLASupportTree();
 
     /// Get the whole mesh united into the output TriangleMesh
+    /// WITHOUT THE PAD
     void merged_mesh(TriangleMesh& outmesh) const;
 
+    void merged_mesh_with_pad(TriangleMesh&) const;
+
     /// Get the sliced 2d layers of the support geometry.
     SlicedSupports slice(float layerh, float init_layerh = -1.0) const;
 
-    /// The function to call when mouse events should be propagated to the
-    /// supports for editing
-    void mouse_event(const MouseEvent&);
+    /// Adding the "pad" (base pool) under the supports
+    const TriangleMesh& add_pad(double min_wall_thickness_mm,
+                                double min_wall_height_mm,
+                                double max_merge_distance_mm,
+                                double edge_radius_mm) const;
+
+    /// Get the pad geometry
+    const TriangleMesh& get_pad() const;
 
-    /// The provided callback will be called if the supports change their shape
-    /// or need to be repainted
-    inline void on_supports_changed(std::function<void()> callback) {
-        m_vcallback = callback;
-    }
 };
 
 }
diff --git a/src/libslic3r/SLAPrint.cpp b/src/libslic3r/SLAPrint.cpp
index 0a0b0ff5c6..6b6455e182 100644
--- a/src/libslic3r/SLAPrint.cpp
+++ b/src/libslic3r/SLAPrint.cpp
@@ -70,7 +70,7 @@ void SLAPrint::clear()
 }
 
 SLAPrint::ApplyStatus SLAPrint::apply(const Model &model,
-                                      const DynamicPrintConfig &config)
+                                      const DynamicPrintConfig &config_in)
 {
 //	if (m_objects.empty())
 //		return APPLY_STATUS_UNCHANGED;
@@ -80,6 +80,11 @@ SLAPrint::ApplyStatus SLAPrint::apply(const Model &model,
     if(m_objects.empty() && model.objects.empty())
         return APPLY_STATUS_UNCHANGED;
 
+    // Temporary: just to have to correct layer height for the rasterization
+    DynamicPrintConfig config(config_in);
+    config.normalize();
+    auto lh = config.opt<ConfigOptionFloat>("layer_height");
+
 	// Temporary quick fix, just invalidate everything.
     {
         for (SLAPrintObject *print_object : m_objects) {
@@ -95,6 +100,7 @@ SLAPrint::ApplyStatus SLAPrint::apply(const Model &model,
         // Generate new SLAPrintObjects.
         for (ModelObject *model_object : m_model.objects) {
             auto po = new SLAPrintObject(this, model_object);
+            po->m_config.layer_height.set(lh);
             m_objects.emplace_back(po);
             for (ModelInstance *oinst : model_object->instances) {
                 Point tr = Point::new_scale(oinst->get_offset()(X),
@@ -138,7 +144,17 @@ void SLAPrint::process()
         slicer.slice(heights, &layers, [](){});
     };
 
-    auto support_points = [](SLAPrintObject&) {
+    auto support_points = [](SLAPrintObject& po) {
+        ModelObject& mo = *po.m_model_object;
+        if(!mo.sla_support_points.empty()) {
+            po.m_supportdata.reset(new SLAPrintObject::SupportData());
+            po.m_supportdata->emesh = sla::to_eigenmesh(mo);
+            po.m_supportdata->support_points = sla::support_points(mo);
+
+            std::cout << "support points copied "
+                      << po.m_supportdata->support_points.rows() << std::endl;
+        }
+
         // for(SLAPrintObject *po : pobjects) {
             // TODO: calculate automatic support points
             // po->m_supportdata->slice_cache contains the slices at this point
@@ -149,7 +165,6 @@ void SLAPrint::process()
     auto support_tree = [this](SLAPrintObject& po) {
         auto& emesh = po.m_supportdata->emesh;
         auto& pts = po.m_supportdata->support_points; // nowhere filled yet
-        auto& supportd = *po.m_supportdata;
         try {
             SupportConfig scfg;  //  TODO fill or replace with po.m_config
 
@@ -161,7 +176,7 @@ void SLAPrint::process()
             };
             ctl.stopcondition = [this](){ return canceled(); };
 
-            supportd.support_tree_ptr.reset(
+             po.m_supportdata->support_tree_ptr.reset(
                         new SLASupportTree(pts, emesh, scfg, ctl));
 
         } catch(sla::SLASupportsStoppedException&) {
@@ -171,13 +186,32 @@ void SLAPrint::process()
     };
 
     // This step generates the sla base pad
-    auto base_pool = [](SLAPrintObject&) {
+    auto base_pool = [](SLAPrintObject& po) {
+        // this step can only go after the support tree has been created
+        // and before the supports had been sliced. (or the slicing has to be
+        // repeated)
+        if(po.is_step_done(slaposSupportTree) &&
+           po.m_supportdata &&
+           po.m_supportdata->support_tree_ptr)
+        {
+            double wt = po.m_config.pad_wall_thickness.getFloat();
+            double h =  po.m_config.pad_wall_height.getFloat();
+            double md = po.m_config.pad_max_merge_distance.getFloat();
+            double er = po.m_config.pad_edge_radius.getFloat();
 
+            po.m_supportdata->support_tree_ptr->add_pad(wt, h, md, er);
+        }
     };
 
-    // Slicing the support geometries similarly to the model slicing procedure
-    auto slice_supports = [](SLAPrintObject&) {
-
+    // Slicing the support geometries similarly to the model slicing procedure.
+    // If the pad had been added previously (see step "base_pool" than it will
+    // be part of the slices)
+    auto slice_supports = [ilh](SLAPrintObject& po) {
+        auto& sd = po.m_supportdata;
+        if(sd && sd->support_tree_ptr) {
+            auto lh = float(po.m_config.layer_height.getFloat());
+            sd->support_slices = sd->support_tree_ptr->slice(lh, ilh);
+        }
     };
 
     // Rasterizing the model objects, and their supports
@@ -198,27 +232,47 @@ void SLAPrint::process()
 
         // For all print objects, go through its initial layers and place them
         // into the layers hash
-        long long initlyridx = static_cast<long long>(scale_(ilh));
+//        long long initlyridx = static_cast<long long>(scale_(ilh));
         for(SLAPrintObject *o : m_objects) {
-            auto& oslices = o->m_model_slices;
-            auto& firstlyr = oslices.front();
-            auto& initlevel = levels[initlyridx];
-            initlevel.emplace_back(firstlyr, o->m_instances);
-
-            // now push the support slices as well
-            // TODO
-
             double lh = o->m_config.layer_height.getFloat();
-            size_t li = 1;
-            for(auto lit = std::next(oslices.begin());
-                lit != oslices.end();
-                ++lit)
-            {
-                double h = ilh + li++ * lh;
+            std::vector<ExPolygons> & oslices = o->m_model_slices;
+            for(int i = 0; i < oslices.size(); ++i) {
+                double h = ilh + i * lh;
                 long long lyridx = static_cast<long long>(scale_(h));
-                auto& lyrs = levels[lyridx];
-                lyrs.emplace_back(*lit, o->m_instances);
+                auto& lyrs = levels[lyridx]; // this initializes a new record
+                lyrs.emplace_back(oslices[i], o->m_instances);
             }
+
+            if(o->m_supportdata) { // deal with the support slices if present
+                auto& sslices = o->m_supportdata->support_slices;
+
+                for(int i = 0; i < sslices.size(); ++i) {
+                    double h = ilh + i * lh;
+                    long long lyridx = static_cast<long long>(scale_(h));
+                    auto& lyrs = levels[lyridx];
+                    lyrs.emplace_back(sslices[i], o->m_instances);
+                }
+            }
+
+//            auto& oslices = o->m_model_slices;
+//            auto& firstlyr = oslices.front();
+//            auto& initlevel = levels[initlyridx];
+//            initlevel.emplace_back(firstlyr, o->m_instances);
+
+//            // now push the support slices as well
+//            // TODO
+
+//            double lh = o->m_config.layer_height.getFloat();
+//            size_t li = 1;
+//            for(auto lit = std::next(oslices.begin());
+//                lit != oslices.end();
+//                ++lit)
+//            {
+//                double h = ilh + li++ * lh;
+//                long long lyridx = static_cast<long long>(scale_(h));
+//                auto& lyrs = levels[lyridx];
+//                lyrs.emplace_back(*lit, o->m_instances);
+//            }
         }
 
         // collect all the keys
@@ -244,10 +298,11 @@ void SLAPrint::process()
 
         // Allocate space for all the layers
         SLAPrinter& printer = *m_printer;
-        printer.layers(unsigned(levels.size()));
+        auto lvlcnt = unsigned(levels.size());
+        printer.layers(lvlcnt);
 
         // procedure to process one height level. This will run in parallel
-        auto process_level = [&keys, &levels, &printer](unsigned level_id) {
+        auto lvlfn = [&keys, &levels, &printer](unsigned level_id) {
             LayerRefs& lrange = levels[keys[level_id]];
 
             for(auto& lyrref : lrange) { // for all layers in the current level
@@ -273,12 +328,10 @@ void SLAPrint::process()
         };
 
         // Sequential version (for testing)
-        // for(unsigned l = 0; l < levels.size(); ++l) process_level(l);
+        // for(unsigned l = 0; l < lvlcnt; ++l) process_level(l);
 
         // Print all the layers in parallel
-        tbb::parallel_for<size_t, decltype(process_level)>(0,
-                                                           levels.size(),
-                                                           process_level);
+        tbb::parallel_for<unsigned, decltype(lvlfn)>(0, lvlcnt, lvlfn);
     };
 
     using slaposFn = std::function<void(SLAPrintObject&)>;
@@ -333,6 +386,9 @@ void SLAPrint::process()
         slapsRasterize, slapsValidate
     };
 
+    // TODO: enable rasterizing
+     m_stepmask[slapsRasterize] = false;
+
     for(size_t s = 0; s < print_program.size(); ++s) {
         auto currentstep = printsteps[s];
 
@@ -352,33 +408,39 @@ void SLAPrint::process()
     set_status(100, L("Slicing done"));
 }
 
-void SLAPrint::render_supports(SLASupportRenderer &renderer)
-{
-    std::cout << "Would show the SLA supports" << std::endl;
-}
-
 SLAPrintObject::SLAPrintObject(SLAPrint *print, ModelObject *model_object):
     Inherited(print),
     m_model_object(model_object),
-    m_supportdata(new SupportData()),
     m_stepmask(slaposCount, true)
 {
-    m_supportdata->emesh = sla::to_eigenmesh(*m_model_object);
-    m_supportdata->support_points = sla::support_points(*m_model_object);
 
-    std::cout << "support points copied " << m_supportdata->support_points.rows() << std::endl;
 }
 
 SLAPrintObject::~SLAPrintObject() {}
 
 TriangleMesh SLAPrintObject::support_mesh() const
 {
-	return make_cube(10., 10., 10.);
+    TriangleMesh trm;
+
+    if(m_supportdata && m_supportdata->support_tree_ptr)
+        m_supportdata->support_tree_ptr->merged_mesh(trm);
+
+    trm.repair();
+
+    std::cout << "support mesh united and returned" << std::endl;
+    return trm;
+//    return make_cube(10., 10., 10.);
 }
 
 TriangleMesh SLAPrintObject::pad_mesh() const
 {
-	return make_cube(10., 10., 10.);
+    if(!m_supportdata || !m_supportdata->support_tree_ptr) {
+        std::cout << "Empty pad mesh returned.." << std::endl;
+        return TriangleMesh();
+    }
+
+    // FIXME: pad mesh is empty here for some reason.
+    return m_supportdata->support_tree_ptr->get_pad();
 }
 
 } // namespace Slic3r
diff --git a/src/libslic3r/SLAPrint.hpp b/src/libslic3r/SLAPrint.hpp
index 1d1bb3bb9e..a1e317abc9 100644
--- a/src/libslic3r/SLAPrint.hpp
+++ b/src/libslic3r/SLAPrint.hpp
@@ -98,33 +98,6 @@ using PrintObjects = std::vector<SLAPrintObject*>;
 
 class TriangleMesh;
 
-class SLASupportRenderer {
-public:
-
-    virtual ~SLASupportRenderer() {}
-
-    enum Buttons {
-        LEFT, RIGHT, MIDDLE
-    };
-
-    enum MType {
-        ENGAGE, RELEASE, HOVER
-    };
-
-    struct MouseEvt {
-        Buttons button; MType type;
-    };
-
-    using ClickCb = std::function<void(MouseEvt)>;
-    using Mesh = TriangleMesh;
-
-    virtual void add_pillar(const Mesh&, ClickCb on_mouse_evt) = 0;
-    virtual void add_head(const Mesh&, ClickCb on_mouse_evt) = 0;
-    virtual void add_bridge(const Mesh&, ClickCb on_mouse_evt) = 0;
-    virtual void add_junction(const Mesh&, ClickCb on_mouse_evt) = 0;
-    virtual void add_pad(const Mesh&, ClickCb on_mouse_evt) = 0;
-};
-
 /**
  * @brief This class is the high level FSM for the SLA printing process.
  *
@@ -156,11 +129,8 @@ public:
     ApplyStatus         apply(const Model &model, const DynamicPrintConfig &config) override;
     void                process() override;
 
-    void                render_supports(SLASupportRenderer& renderer);
-
     template<class Fmt> void export_raster(const std::string& fname) {
         if(m_printer) m_printer->save<Fmt>(fname);
-        std::cout << "Would export the SLA raster" << std::endl;
     }
     const PrintObjects& objects() const { return m_objects; }
 
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 3715843fb8..dcc02e56f1 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -1871,8 +1871,21 @@ void Plater::priv::on_process_completed(wxCommandEvent &evt)
     case ptSLA:
         // Update the SLAPrint from the current Model, so that the reload_scene()
         // pulls the correct data.
-        if (this->update_background_process() & UPDATE_BACKGROUND_PROCESS_RESTART)
-            this->schedule_background_process();
+//        if (this->update_background_process() & UPDATE_BACKGROUND_PROCESS_RESTART)
+//            this->schedule_background_process();
+
+        {
+//        for(SLAPrintObject * po: sla_print.objects()) {
+//            TriangleMesh&& suppmesh = po->support_mesh();
+//            if(suppmesh.facets_count() > 0) {
+//                ModelObject* mo = model.add_object();
+//                for(const SLAPrintObject::Instance& inst : po->instances() ) {
+//                    mo->add_instance(*(mo->instances[inst.instance_id.id]));
+//                    mo->add_volume(suppmesh);
+//                }
+//            }
+//        }
+        }
         _3DScene::reload_scene(canvas3D, true);
         break;
     }