From ac8eab5fa8e6c38faf788349bcb4f0f707d6bbbe Mon Sep 17 00:00:00 2001
From: tamasmeszaros <meszaros.q@gmail.com>
Date: Fri, 8 Nov 2019 16:51:43 +0100
Subject: Enhanced hollowing scheme, closing distance working as expected.

---
 src/libslic3r/SLA/Hollowing.cpp | 127 ++++++++++++++++++++++++++++++----------
 1 file changed, 97 insertions(+), 30 deletions(-)

(limited to 'src/libslic3r/SLA')

diff --git a/src/libslic3r/SLA/Hollowing.cpp b/src/libslic3r/SLA/Hollowing.cpp
index 430900313..c3993f2c8 100644
--- a/src/libslic3r/SLA/Hollowing.cpp
+++ b/src/libslic3r/SLA/Hollowing.cpp
@@ -1,55 +1,122 @@
-#include "Hollowing.hpp"
-#include <openvdb/tools/Filter.h>
-#include <openvdb/tools/LevelSetRebuild.h>
-#include <openvdb/tools/LevelSetFilter.h>
 #include <functional>
 
+//#include <openvdb/tools/Filter.h>
+#include <boost/log/trivial.hpp>
+
+#include "Hollowing.hpp"
+#include <libslic3r/MTUtils.hpp>
+
 namespace Slic3r {
 namespace sla {
 
-namespace {
+//namespace {
+
+//void filter_grid_sla(openvdb::FloatGrid::Ptr &grid, double scale, double /*thickness*/, double flatness, double closing_dist)
+//{
+//    static const double ROUNDNESS_COEFF = 1.;
+    
+//    // Filtering:
+//    if (flatness > 0.) {
+//        double rounding = ROUNDNESS_COEFF * flatness;
+//        int width = int(rounding * scale);
+//        int count = 1;
+//        openvdb::tools::Filter<openvdb::FloatGrid>{*grid}.gaussian(width, count);
+//    }
+//}
+
+//}
+
+template<class S, class = FloatingOnly<S>>
+inline void _scale(S s, TriangleMesh &m) { m.scale(float(s)); }
 
-void filter_grid_sla(openvdb::FloatGrid &grid, double scale, double /*thickness*/, double flatness)
+template<class S, class = FloatingOnly<S>>
+inline void _scale(S s, sla::Contour3D &m)
 {
-    static const double ROUNDNESS_COEFF = 1.;
-    
-    // Filtering:
-    if (flatness > 0.) {
-        double rounding = ROUNDNESS_COEFF * flatness;
-        int width = int(rounding * scale);
-        int count = 1;
-        openvdb::tools::Filter<openvdb::FloatGrid>{grid}.gaussian(width, count);
-    }
+    for (auto &p : m.points) p *= s;
 }
-//    openvdb::tools::levelSetRebuild(grid, -float(thickness * 2));
-//    filter_grid_sla(grid, scale, thickness, flatness);
 
-//    openvdb::tools::levelSetRebuild(grid, float(thickness));
+template<class Mesh>
+remove_cvref_t<Mesh> _grid_to_mesh(const openvdb::FloatGrid &grid,
+                                   double                    isosurf,
+                                   double                    adapt);
+
+template<>
+TriangleMesh _grid_to_mesh<TriangleMesh>(const openvdb::FloatGrid &grid,
+                                   double                    isosurf,
+                                   double                    adapt)
+{
+    return grid_to_mesh(grid, isosurf, adapt);
+}
 
+template<>
+sla::Contour3D _grid_to_mesh<sla::Contour3D>(const openvdb::FloatGrid &grid,
+                                         double                    isosurf,
+                                         double                    adapt)
+{
+    return grid_to_contour3d(grid, isosurf, adapt);
+}
 
-void redist_grid_sla(openvdb::FloatGrid &grid, double scale, double thickness, double flatness)
+template<class Mesh>
+remove_cvref_t<Mesh> _generate_interior(Mesh &&mesh,
+                                        double min_thickness,
+                                        double voxel_scale,
+                                        double closing_dist)
 {
-//    openvdb::tools::levelSetRebuild(grid, -float(scale * thickness));
+//    namespace plc = std::placeholders;
+//    auto filt = std::bind(redist_grid_sla, plc::_1, plc::_2, plc::_3, flatness, closing_dist);
+//    return hollowed_interior(mesh, min_thickness, quality, filt);
+
+    using MMesh = remove_cvref_t<Mesh>;
+    MMesh imesh{std::forward<Mesh>(mesh)};
     
+    _scale(voxel_scale, imesh);
     
-    openvdb::tools::LevelSetFilter<openvdb::FloatGrid> filt{grid};
+    double offset = voxel_scale * min_thickness;
+    double D = voxel_scale * closing_dist;
+    float  out_range = 0.1f * float(offset);
+    float  in_range = 1.1f * float(offset + D);
+    auto gridptr = mesh_to_grid(imesh, {}, out_range, in_range);
     
-//    filt.gaussian(int(flatness * scale));
+    assert(gridptr);
     
-//    openvdb::tools::levelSetRebuild(grid, float(scale * thickness));
-    //grid = openvdb::tools::topologyToLevelSet(grid);
-}
-
+    if (!gridptr) {
+        BOOST_LOG_TRIVIAL(error) << "Returned OpenVDB grid is NULL";
+        return MMesh{};
+    }
+    
+    if (closing_dist > .0) {
+        gridptr = redistance_grid(*gridptr, -(offset + D), double(in_range));
+    } else {
+        D = -offset;
+    }
+    
+//    openvdb::tools::Filter<openvdb::FloatGrid> filt{*gridptr};
+//    filt.offset(float(offset + D));
+    
+    double iso_surface = D;
+    double adaptivity = 0.;
+    auto omesh = _grid_to_mesh<MMesh>(*gridptr, iso_surface, adaptivity);
+    
+    _scale(1. / voxel_scale, omesh);
+    
+    return omesh;
 }
 
 TriangleMesh generate_interior(const TriangleMesh &mesh,
                                double              min_thickness,
                                double              quality,
-                               double              flatness)
+                               double              closing_dist)
 {
-    namespace plc = std::placeholders;
-    auto filt = std::bind(filter_grid_sla, plc::_1, plc::_2, plc::_3, flatness);
-    return hollowed_interior(mesh, min_thickness, quality, filt);
+    static const double MAX_OVERSAMPL = 7.;
+        
+    // I can't figure out how to increase the grid resolution through openvdb API
+    // so the model will be scaled up before conversion and the result scaled
+    // down. Voxels have a unit size. If I set voxelSize smaller, it scales
+    // the whole geometry down, and doesn't increase the number of voxels.
+    //
+    // max 8x upscale, min is native voxel size
+    auto voxel_scale = (1.0 + MAX_OVERSAMPL * quality);
+    return _generate_interior(mesh, min_thickness, voxel_scale, closing_dist);
 }
 
 }} // namespace Slic3r::sla
-- 
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