Fixed volume transformations in SLA:

Volume transformations were ignored in SLA mode. This did not matter for plain STLs
and PS own 3MF, because in those cases, the volume trafo was identity. Importing
a 3rd party 3MF leads to issues with support/holes placement and generation.
Fixes #6100 and #6744.

src/libslic3r/SLA/ReprojectPointsOnMesh.hpp

@@ -35,11 +35,24 @@ inline void reproject_points_and_holes(ModelObject *object)
     TriangleMesh rmsh = object->raw_mesh();
     IndexedMesh emesh{rmsh};
 
-    if (has_sppoints)
+    const Transform3f& tr = object->volumes.front()->get_matrix().cast<float>();
-        reproject_support_points(emesh, object->sla_support_points);
 
-    if (has_holes)
+    if (has_sppoints) {
-        reproject_support_points(emesh, object->sla_drain_holes);
+        SupportPoints transformed_points = object->sla_support_points;
+        for (SupportPoint& pt : transformed_points)
+            pt.pos = tr * pt.pos;
+        reproject_support_points(emesh, transformed_points);
+    }
+
+    if (has_holes) {
+        DrainHoles transformed_holes = object->sla_drain_holes;
+        for (DrainHole& hole : transformed_holes) {
+            // Hole normals are not transformed here, but the reprojection
+            // does not use them.
+            hole.pos = tr * hole.pos;
+        }
+        reproject_support_points(emesh, transformed_holes);
+    }
 }
 
 }}

src/libslic3r/SLAPrint.cpp

@@ -1167,7 +1167,9 @@ sla::SupportPoints SLAPrintObject::transformed_support_points() const
 {
     assert(m_model_object != nullptr);
     auto spts = m_model_object->sla_support_points;
-    auto tr = trafo().cast<float>();
+
+    auto tr = (trafo() * m_model_object->volumes.front()->get_transformation().get_matrix()).cast<float>();
+
     for (sla::SupportPoint& suppt : spts) {
         suppt.pos = tr * suppt.pos;
     }
@@ -1179,8 +1181,8 @@ sla::DrainHoles SLAPrintObject::transformed_drainhole_points() const
 {
     assert(m_model_object != nullptr);
     auto pts = m_model_object->sla_drain_holes;
-    auto tr = trafo().cast<float>();
+    Transform3f tr = (trafo() * m_model_object->volumes.front()->get_matrix()).cast<float>();
-    auto sc = m_model_object->instances.front()->get_scaling_factor().cast<float>();
+    Vec3f sc = Geometry::Transformation(tr.cast<double>()).get_scaling_factor().cast<float>();
     for (sla::DrainHole &hl : pts) {
         hl.pos = tr * hl.pos;
         hl.normal = tr * hl.normal - tr.translation();

src/slic3r/GUI/Gizmos/GLGizmoHollow.cpp

@@ -106,9 +106,13 @@ void GLGizmoHollow::render_points(const Selection& selection, bool picking) cons
         shader->start_using();
     ScopeGuard guard([shader]() { if (shader) shader->stop_using(); });
 
-    const GLVolume* vol = selection.get_volume(*selection.get_volume_idxs().begin());
+    const ModelObject* mo = m_c->selection_info()->model_object();
-    const Transform3d& instance_scaling_matrix_inverse = vol->get_instance_transformation().get_matrix(true, true, false, true).inverse();
+    const ModelInstance* mi = mo->instances[m_c->selection_info()->get_active_instance()];
-    const Transform3d& instance_matrix = vol->get_instance_transformation().get_matrix();
+    const ModelVolume* mv = mo->volumes.front();
+    Geometry::Transformation transformation(mi->get_transformation() * mv->get_transformation());
+
+    const Transform3d& instance_scaling_matrix_inverse = transformation.get_matrix(true, true, false, true).inverse();
+    const Transform3d& instance_matrix = transformation.get_matrix();
 
     glsafe(::glPushMatrix());
     glsafe(::glTranslated(0.0, 0.0, m_c->selection_info()->get_sla_shift()));
@@ -117,6 +121,7 @@ void GLGizmoHollow::render_points(const Selection& selection, bool picking) cons
     std::array<float, 4> render_color;
     const sla::DrainHoles& drain_holes = m_c->selection_info()->model_object()->sla_drain_holes;
     size_t cache_size = drain_holes.size();
+    const GLVolume* vol = selection.get_volume(*selection.get_volume_idxs().begin());
 
     for (size_t i = 0; i < cache_size; ++i) {
         const sla::DrainHole& drain_hole = drain_holes[i];
@@ -184,13 +189,13 @@ bool GLGizmoHollow::is_mesh_point_clipped(const Vec3d& point) const
     if (m_c->object_clipper()->get_position() == 0.)
         return false;
 
-    auto sel_info = m_c->selection_info();
     int active_inst = m_c->selection_info()->get_active_instance();
-    const ModelInstance* mi = sel_info->model_object()->instances[active_inst];
+    const ModelObject* mo = m_c->selection_info()->model_object();
-    const Transform3d& trafo = mi->get_transformation().get_matrix();
+    const ModelInstance* mi = mo->instances[active_inst];
+    const Transform3d trafo = (mi->get_transformation() * mo->volumes.front()->get_transformation()).get_matrix();
 
     Vec3d transformed_point =  trafo * point;
-    transformed_point(2) += sel_info->get_sla_shift();
+    transformed_point(2) += m_c->selection_info()->get_sla_shift();
     return m_c->object_clipper()->get_clipping_plane()->is_point_clipped(transformed_point);
 }
 
@@ -205,9 +210,12 @@ bool GLGizmoHollow::unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec3f, V
 
     const Camera& camera = wxGetApp().plater()->get_camera();
     const Selection& selection = m_parent.get_selection();
-    const GLVolume* volume = selection.get_volume(*selection.get_volume_idxs().begin());
+    const ModelObject* mo = m_c->selection_info()->model_object();
-    Geometry::Transformation trafo = volume->get_instance_transformation();
+    const ModelInstance* mi = mo->instances[selection.get_instance_idx()];
-    trafo.set_offset(trafo.get_offset() + Vec3d(0., 0., m_c->selection_info()->get_sla_shift()));
+    const ModelVolume* mv = mo->volumes.front();
+
+    Transform3d trafo = mi->get_transformation().get_matrix() * mv->get_matrix();
+    trafo.pretranslate(Vec3d(0., 0., m_c->selection_info()->get_sla_shift()));
 
     double clp_dist = m_c->object_clipper()->get_position();
     const ClippingPlane* clp = m_c->object_clipper()->get_clipping_plane();
@@ -217,7 +225,7 @@ bool GLGizmoHollow::unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec3f, V
     Vec3f normal;
     if (m_c->raycaster()->raycaster()->unproject_on_mesh(
             mouse_pos,
-            trafo.get_matrix(),
+            trafo,
             camera,
             hit,
             normal,
@@ -307,8 +315,11 @@ bool GLGizmoHollow::gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_pos
         GLSelectionRectangle::EState rectangle_status = m_selection_rectangle.get_state();
 
         // First collect positions of all the points in world coordinates.
-        Geometry::Transformation trafo = mo->instances[active_inst]->get_transformation();
+        const ModelInstance* mi = mo->instances[active_inst];
+        const ModelVolume* mv = mo->volumes.front();
+        Geometry::Transformation trafo(mi->get_transformation() * mv->get_transformation());
         trafo.set_offset(trafo.get_offset() + Vec3d(0., 0., m_c->selection_info()->get_sla_shift()));
+
         std::vector<Vec3d> points;
         for (unsigned int i=0; i<mo->sla_drain_holes.size(); ++i)
             points.push_back(trafo.get_matrix() * mo->sla_drain_holes[i].pos.cast<double>());

src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp

@@ -127,9 +127,13 @@ void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking)
             shader->stop_using();
     });
 
-    const GLVolume* vol = selection.get_volume(*selection.get_volume_idxs().begin());
+    const ModelObject* mo = m_c->selection_info()->model_object();
-    const Transform3d& instance_scaling_matrix_inverse = vol->get_instance_transformation().get_matrix(true, true, false, true).inverse();
+    const ModelInstance* mi = mo->instances[m_c->selection_info()->get_active_instance()];
-    const Transform3d& instance_matrix = vol->get_instance_transformation().get_matrix();
+    const ModelVolume* mv = mo->volumes.front();
+    Geometry::Transformation transformation(mi->get_transformation() * mv->get_transformation());
+
+    const Transform3d& instance_scaling_matrix_inverse = transformation.get_matrix(true, true, false, true).inverse();
+    const Transform3d& instance_matrix = transformation.get_matrix();
     float z_shift = m_c->selection_info()->get_sla_shift();
 
     glsafe(::glPushMatrix());
@@ -137,6 +141,7 @@ void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking)
     glsafe(::glMultMatrixd(instance_matrix.data()));
 
     std::array<float, 4> render_color;
+    const GLVolume* vol = selection.get_volume(*selection.get_volume_idxs().begin());
     for (size_t i = 0; i < cache_size; ++i) {
         const sla::SupportPoint& support_point = m_editing_mode ? m_editing_cache[i].support_point : m_normal_cache[i];
         const bool& point_selected = m_editing_mode ? m_editing_cache[i].selected : false;
@@ -265,13 +270,13 @@ bool GLGizmoSlaSupports::is_mesh_point_clipped(const Vec3d& point) const
     if (m_c->object_clipper()->get_position() == 0.)
         return false;
 
-    auto sel_info = m_c->selection_info();
     int active_inst = m_c->selection_info()->get_active_instance();
-    const ModelInstance* mi = sel_info->model_object()->instances[active_inst];
+    const ModelObject* mo = m_c->selection_info()->model_object();
-    const Transform3d& trafo = mi->get_transformation().get_matrix();
+    const ModelInstance* mi = mo->instances[active_inst];
+    const Transform3d trafo = (mi->get_transformation() * mo->volumes.front()->get_transformation()).get_matrix();
 
     Vec3d transformed_point =  trafo * point;
-    transformed_point(2) += sel_info->get_sla_shift();
+    transformed_point(2) += m_c->selection_info()->get_sla_shift();
     return m_c->object_clipper()->get_clipping_plane()->is_point_clipped(transformed_point);
 }
 
@@ -286,9 +291,12 @@ bool GLGizmoSlaSupports::unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec
 
     const Camera& camera = wxGetApp().plater()->get_camera();
     const Selection& selection = m_parent.get_selection();
-    const GLVolume* volume = selection.get_volume(*selection.get_volume_idxs().begin());
+    const ModelObject* mo = m_c->selection_info()->model_object();
-    Geometry::Transformation trafo = volume->get_instance_transformation();
+    const ModelInstance* mi = mo->instances[selection.get_instance_idx()];
-    trafo.set_offset(trafo.get_offset() + Vec3d(0., 0., m_c->selection_info()->get_sla_shift()));
+    const ModelVolume* mv = mo->volumes.front();
+
+    Transform3d trafo = mi->get_transformation().get_matrix() * mv->get_matrix();
+    trafo.pretranslate(Vec3d(0., 0., m_c->selection_info()->get_sla_shift()));
 
     double clp_dist = m_c->object_clipper()->get_position();
     const ClippingPlane* clp = m_c->object_clipper()->get_clipping_plane();
@@ -298,7 +306,7 @@ bool GLGizmoSlaSupports::unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec
     Vec3f normal;
     if (m_c->raycaster()->raycaster()->unproject_on_mesh(
             mouse_pos,
-            trafo.get_matrix(),
+            trafo,
             camera,
             hit,
             normal,
@@ -388,8 +396,11 @@ bool GLGizmoSlaSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
             GLSelectionRectangle::EState rectangle_status = m_selection_rectangle.get_state();
 
             // First collect positions of all the points in world coordinates.
-            Geometry::Transformation trafo = mo->instances[active_inst]->get_transformation();
+            const ModelInstance* mi = mo->instances[active_inst];
+            const ModelVolume* mv = mo->volumes.front();
+            Geometry::Transformation trafo(mi->get_transformation() * mv->get_transformation());
             trafo.set_offset(trafo.get_offset() + Vec3d(0., 0., m_c->selection_info()->get_sla_shift()));
+
             std::vector<Vec3d> points;
             for (unsigned int i=0; i<m_editing_cache.size(); ++i)
                 points.push_back(trafo.get_matrix() * m_editing_cache[i].support_point.pos.cast<double>());