Fixed painting gizmos with modifiers below the bed:

- When a modifier was below the bed and all the object parts above, it would clip
  the modifier but not triangulate the cut.
- When an object part was below, it would triangulate all modifiers with
  opaque orange color.

Both should now be fixed.

4 files changed, 27 insertions, 17 deletions

diff --git a/src/slic3r/GUI/3DScene.cpp b/src/slic3r/GUI/3DScene.cpp
index 2d49a8bf3..ba72c432d 100644
--- a/src/slic3r/GUI/3DScene.cpp
+++ b/src/slic3r/GUI/3DScene.cpp
@@ -409,6 +409,11 @@ GLVolume::GLVolume(float r, float g, float b, float a)
     set_render_color(color);
 }
 
+void GLVolume::set_color(const std::array<float, 4>& rgba)
+{
+    color = rgba;
+}
+
 void GLVolume::set_render_color(float r, float g, float b, float a)
 {
     render_color = { r, g, b, a };
@@ -458,8 +463,9 @@ void GLVolume::set_render_color()
         render_color[3] = color[3];
 }
 
-void GLVolume::set_color_from_model_volume(const ModelVolume& model_volume)
+std::array<float, 4> color_from_model_volume(const ModelVolume& model_volume)
 {
+    std::array<float, 4> color;
     if (model_volume.is_negative_volume()) {
         color[0] = 0.2f;
         color[1] = 0.2f;
@@ -481,6 +487,7 @@ void GLVolume::set_color_from_model_volume(const ModelVolume& model_volume)
         color[2] = 1.0f;
     }
     color[3] = model_volume.is_model_part() ? 1.f : 0.5f;
+    return color;
 }
 
 Transform3d GLVolume::world_matrix() const
@@ -635,7 +642,7 @@ int GLVolumeCollection::load_object_volume(
     color[3] = model_volume->is_model_part() ? 1.f : 0.5f;
     this->volumes.emplace_back(new GLVolume(color));
     GLVolume& v = *this->volumes.back();
-    v.set_color_from_model_volume(*model_volume);
+    v.set_color(color_from_model_volume(*model_volume));
 #if ENABLE_SMOOTH_NORMALS
     v.indexed_vertex_array.load_mesh(mesh, true);
 #else
diff --git a/src/slic3r/GUI/3DScene.hpp b/src/slic3r/GUI/3DScene.hpp
index 35abe8bd4..1a85cc41e 100644
--- a/src/slic3r/GUI/3DScene.hpp
+++ b/src/slic3r/GUI/3DScene.hpp
@@ -39,6 +39,10 @@ class ModelObject;
 class ModelVolume;
 enum ModelInstanceEPrintVolumeState : unsigned char;
 
+// Return appropriate color based on the ModelVolume.
+std::array<float, 4> color_from_model_volume(const ModelVolume& model_volume);
+
+
 // A container for interleaved arrays of 3D vertices and normals,
 // possibly indexed by triangles and / or quads.
 class GLIndexedVertexArray {
@@ -393,6 +397,7 @@ public:
         return out;
     }
 
+    void set_color(const std::array<float, 4>& rgba);
     void set_render_color(float r, float g, float b, float a);
     void set_render_color(const std::array<float, 4>& rgba);
     // Sets render color in dependence of current state
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index d790e937c..33399e38d 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -1845,7 +1845,7 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
                     volume->extruder_id = extruder_id;
 
                 volume->is_modifier = !mvs->model_volume->is_model_part();
-                volume->set_color_from_model_volume(*mvs->model_volume);
+                volume->set_color(color_from_model_volume(*mvs->model_volume));
 
                 // updates volumes transformations
                 volume->set_instance_transformation(mvs->model_volume->get_object()->instances[mvs->composite_id.instance_id]->get_transformation());
diff --git a/src/slic3r/GUI/Gizmos/GLGizmosCommon.cpp b/src/slic3r/GUI/Gizmos/GLGizmosCommon.cpp
index 18ce9d73c..b22e72be9 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmosCommon.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmosCommon.cpp
@@ -152,7 +152,7 @@ void InstancesHider::on_update()
         canvas->toggle_sla_auxiliaries_visibility(m_show_supports, mo, active_inst);
         canvas->set_use_clipping_planes(true);
         // Some objects may be sinking, do not show whatever is below the bed.
-        canvas->set_clipping_plane(0, ClippingPlane(Vec3d::UnitZ(), 0.));
+        canvas->set_clipping_plane(0, ClippingPlane(Vec3d::UnitZ(), -SINKING_Z_THRESHOLD));
         canvas->set_clipping_plane(1, ClippingPlane(-Vec3d::UnitZ(), std::numeric_limits<double>::max()));
 
 
@@ -164,12 +164,7 @@ void InstancesHider::on_update()
             m_clippers.clear();
             for (const TriangleMesh* mesh : meshes) {
                 m_clippers.emplace_back(new MeshClipper);
-                if (mo->get_instance_min_z(active_inst) < SINKING_Z_THRESHOLD)
-                    m_clippers.back()->set_plane(ClippingPlane(-Vec3d::UnitZ(), 0.));
-                else {
-                    m_clippers.back()->set_plane(ClippingPlane::ClipsNothing());
-                    m_clippers.back()->set_limiting_plane(ClippingPlane::ClipsNothing());
-                }
+                m_clippers.back()->set_plane(ClippingPlane(-Vec3d::UnitZ(), -SINKING_Z_THRESHOLD));
                 m_clippers.back()->set_mesh(*mesh);
             }
             m_old_meshes = meshes;
@@ -218,8 +213,16 @@ void InstancesHider::render_cut() const
             clipper->set_limiting_plane(ClippingPlane::ClipsNothing());
 
         glsafe(::glPushMatrix());
-        glsafe(::glColor3f(0.8f, 0.3f, 0.0f));
+        if (mv->is_model_part())
+            glsafe(::glColor3f(0.8f, 0.3f, 0.0f));
+        else {
+            const std::array<float, 4>& c = color_from_model_volume(*mv);
+            glsafe(::glColor4f(c[0], c[1], c[2], c[3]));
+        }
+        glsafe(::glPushAttrib(GL_DEPTH_TEST));
+        glsafe(::glDisable(GL_DEPTH_TEST));
         clipper->render_cut();
+        glsafe(::glPopAttrib());
         glsafe(::glPopMatrix());
 
         ++clipper_id;
@@ -385,8 +388,6 @@ void ObjectClipper::on_update()
 
         m_active_inst_bb_radius =
             mo->instance_bounding_box(get_pool()->selection_info()->get_active_instance()).radius();
-        //if (has_hollowed && m_clp_ratio != 0.)
-        //    m_clp_ratio = 0.25;
     }
 }
 
@@ -407,7 +408,6 @@ void ObjectClipper::render_cut() const
     const SelectionInfo* sel_info = get_pool()->selection_info();
     const ModelObject* mo = sel_info->model_object();
     Geometry::Transformation inst_trafo = mo->instances[sel_info->get_active_instance()]->get_transformation();
-    const bool sinking = mo->bounding_box().min.z() < SINKING_Z_THRESHOLD;
 
     size_t clipper_id = 0;
     for (const ModelVolume* mv : mo->volumes) {
@@ -418,9 +418,7 @@ void ObjectClipper::render_cut() const
         auto& clipper = m_clippers[clipper_id];
         clipper->set_plane(*m_clp);
         clipper->set_transformation(trafo);
-        clipper->set_limiting_plane(sinking ?
-                                    ClippingPlane(Vec3d::UnitZ(), 0.)
-                                  : ClippingPlane::ClipsNothing());
+        clipper->set_limiting_plane(ClippingPlane(Vec3d::UnitZ(), -SINKING_Z_THRESHOLD));
         glsafe(::glPushMatrix());
         glsafe(::glColor3f(1.0f, 0.37f, 0.0f));
         clipper->render_cut();