PrusaSlicer/xs/src/libslic3r/ModelArrange.hpp

406 lines
15 KiB
C++

#ifndef MODELARRANGE_HPP
#define MODELARRANGE_HPP
#include "Model.hpp"
#include "SVG.hpp"
#include <libnest2d.h>
#include <numeric>
#include <ClipperUtils.hpp>
namespace Slic3r {
namespace arr {
using namespace libnest2d;
std::string toString(const Model& model, bool holes = true) {
std::stringstream ss;
ss << "{\n";
for(auto objptr : model.objects) {
if(!objptr) continue;
auto rmesh = objptr->raw_mesh();
for(auto objinst : objptr->instances) {
if(!objinst) continue;
Slic3r::TriangleMesh tmpmesh = rmesh;
tmpmesh.scale(objinst->scaling_factor);
objinst->transform_mesh(&tmpmesh);
ExPolygons expolys = tmpmesh.horizontal_projection();
for(auto& expoly_complex : expolys) {
auto tmp = expoly_complex.simplify(1.0/SCALING_FACTOR);
if(tmp.empty()) continue;
auto expoly = tmp.front();
expoly.contour.make_clockwise();
for(auto& h : expoly.holes) h.make_counter_clockwise();
ss << "\t{\n";
ss << "\t\t{\n";
for(auto v : expoly.contour.points) ss << "\t\t\t{"
<< v.x << ", "
<< v.y << "},\n";
{
auto v = expoly.contour.points.front();
ss << "\t\t\t{" << v.x << ", " << v.y << "},\n";
}
ss << "\t\t},\n";
// Holes:
ss << "\t\t{\n";
if(holes) for(auto h : expoly.holes) {
ss << "\t\t\t{\n";
for(auto v : h.points) ss << "\t\t\t\t{"
<< v.x << ", "
<< v.y << "},\n";
{
auto v = h.points.front();
ss << "\t\t\t\t{" << v.x << ", " << v.y << "},\n";
}
ss << "\t\t\t},\n";
}
ss << "\t\t},\n";
ss << "\t},\n";
}
}
}
ss << "}\n";
return ss.str();
}
void toSVG(SVG& svg, const Model& model) {
for(auto objptr : model.objects) {
if(!objptr) continue;
auto rmesh = objptr->raw_mesh();
for(auto objinst : objptr->instances) {
if(!objinst) continue;
Slic3r::TriangleMesh tmpmesh = rmesh;
tmpmesh.scale(objinst->scaling_factor);
objinst->transform_mesh(&tmpmesh);
ExPolygons expolys = tmpmesh.horizontal_projection();
svg.draw(expolys);
}
}
}
// A container which stores a pointer to the 3D object and its projected
// 2D shape from top view.
using ShapeData2D =
std::vector<std::pair<Slic3r::ModelInstance*, Item>>;
ShapeData2D projectModelFromTop(const Slic3r::Model &model) {
ShapeData2D ret;
auto s = std::accumulate(model.objects.begin(), model.objects.end(), 0,
[](size_t s, ModelObject* o){
return s + o->instances.size();
});
ret.reserve(s);
for(auto objptr : model.objects) {
if(objptr) {
auto rmesh = objptr->raw_mesh();
for(auto objinst : objptr->instances) {
if(objinst) {
Slic3r::TriangleMesh tmpmesh = rmesh;
ClipperLib::PolygonImpl pn;
tmpmesh.scale(objinst->scaling_factor);
// TODO export the exact 2D projection
auto p = tmpmesh.convex_hull();
p.make_clockwise();
p.append(p.first_point());
pn.Contour = Slic3rMultiPoint_to_ClipperPath( p );
// Efficient conversion to item.
Item item(std::move(pn));
// Invalid geometries would throw exceptions when arranging
if(item.vertexCount() > 3) {
item.rotation(objinst->rotation);
item.translation( {
ClipperLib::cInt(objinst->offset.x/SCALING_FACTOR),
ClipperLib::cInt(objinst->offset.y/SCALING_FACTOR)
});
ret.emplace_back(objinst, item);
}
}
}
}
}
return ret;
}
/**
* \brief Arranges the model objects on the screen.
*
* The arrangement considers multiple bins (aka. print beds) for placing all
* the items provided in the model argument. If the items don't fit on one
* print bed, the remaining will be placed onto newly created print beds.
* The first_bin_only parameter, if set to true, disables this behaviour and
* makes sure that only one print bed is filled and the remaining items will be
* untouched. When set to false, the items which could not fit onto the
* print bed will be placed next to the print bed so the user should see a
* pile of items on the print bed and some other piles outside the print
* area that can be dragged later onto the print bed as a group.
*
* \param model The model object with the 3D content.
* \param dist The minimum distance which is allowed for any pair of items
* on the print bed in any direction.
* \param bb The bounding box of the print bed. It corresponds to the 'bin'
* for bin packing.
* \param first_bin_only This parameter controls whether to place the
* remaining items which do not fit onto the print area next to the print
* bed or leave them untouched (let the user arrange them by hand or remove
* them).
*/
bool arrange(Model &model, coordf_t dist, const Slic3r::BoundingBoxf* bb,
bool first_bin_only,
std::function<void(unsigned)> progressind)
{
using ArrangeResult = _IndexedPackGroup<PolygonImpl>;
bool ret = true;
// Create the arranger config
auto min_obj_distance = static_cast<Coord>(dist/SCALING_FACTOR);
// Get the 2D projected shapes with their 3D model instance pointers
auto shapemap = arr::projectModelFromTop(model);
bool hasbin = bb != nullptr && bb->defined;
double area_max = 0;
// Copy the references for the shapes only as the arranger expects a
// sequence of objects convertible to Item or ClipperPolygon
std::vector<std::reference_wrapper<Item>> shapes;
shapes.reserve(shapemap.size());
std::for_each(shapemap.begin(), shapemap.end(),
[&shapes, min_obj_distance, &area_max, hasbin]
(ShapeData2D::value_type& it)
{
shapes.push_back(std::ref(it.second));
});
Box bin;
if(hasbin) {
// Scale up the bounding box to clipper scale.
BoundingBoxf bbb = *bb;
bbb.scale(1.0/SCALING_FACTOR);
bin = Box({
static_cast<libnest2d::Coord>(bbb.min.x),
static_cast<libnest2d::Coord>(bbb.min.y)
},
{
static_cast<libnest2d::Coord>(bbb.max.x),
static_cast<libnest2d::Coord>(bbb.max.y)
});
}
// Will use the DJD selection heuristic with the BottomLeft placement
// strategy
using Arranger = Arranger<NfpPlacer, FirstFitSelection>;
using PConf = Arranger::PlacementConfig;
using SConf = Arranger::SelectionConfig;
PConf pcfg; // Placement configuration
SConf scfg; // Selection configuration
// Align the arranged pile into the center of the bin
pcfg.alignment = PConf::Alignment::CENTER;
// Start placing the items from the center of the print bed
pcfg.starting_point = PConf::Alignment::CENTER;
// TODO cannot use rotations until multiple objects of same geometry can
// handle different rotations
// arranger.useMinimumBoundigBoxRotation();
pcfg.rotations = { 0.0 };
// The accuracy of optimization. Goes from 0.0 to 1.0 and scales performance
pcfg.accuracy = 0.4f;
// Magic: we will specify what is the goal of arrangement... In this case
// we override the default object function to make the larger items go into
// the center of the pile and smaller items orbit it so the resulting pile
// has a circle-like shape. This is good for the print bed's heat profile.
// We alse sacrafice a bit of pack efficiency for this to work. As a side
// effect, the arrange procedure is a lot faster (we do not need to
// calculate the convex hulls)
pcfg.object_function = [bin, hasbin](
NfpPlacer::Pile& pile, // The currently arranged pile
const Item &item,
double /*area*/, // Sum area of items (not needed)
double norm, // A norming factor for physical dimensions
double penality) // Min penality in case of bad arrangement
{
using pl = PointLike;
static const double BIG_ITEM_TRESHOLD = 0.2;
static const double GRAVITY_RATIO = 0.5;
static const double DENSITY_RATIO = 1.0 - GRAVITY_RATIO;
// We will treat big items (compared to the print bed) differently
NfpPlacer::Pile bigs;
bigs.reserve(pile.size());
for(auto& p : pile) {
auto pbb = ShapeLike::boundingBox(p);
auto na = std::sqrt(pbb.width()*pbb.height())/norm;
if(na > BIG_ITEM_TRESHOLD) bigs.emplace_back(p);
}
// Candidate item bounding box
auto ibb = item.boundingBox();
// Calculate the full bounding box of the pile with the candidate item
pile.emplace_back(item.transformedShape());
auto fullbb = ShapeLike::boundingBox(pile);
pile.pop_back();
// The bounding box of the big items (they will accumulate in the center
// of the pile
auto bigbb = bigs.empty()? fullbb : ShapeLike::boundingBox(bigs);
// The size indicator of the candidate item. This is not the area,
// but almost...
auto itemnormarea = std::sqrt(ibb.width()*ibb.height())/norm;
// Will hold the resulting score
double score = 0;
if(itemnormarea > BIG_ITEM_TRESHOLD) {
// This branch is for the bigger items..
// Here we will use the closest point of the item bounding box to
// the already arranged pile. So not the bb center nor the a choosen
// corner but whichever is the closest to the center. This will
// prevent unwanted strange arrangements.
auto minc = ibb.minCorner(); // bottom left corner
auto maxc = ibb.maxCorner(); // top right corner
// top left and bottom right corners
auto top_left = PointImpl{getX(minc), getY(maxc)};
auto bottom_right = PointImpl{getX(maxc), getY(minc)};
auto cc = fullbb.center(); // The gravity center
// Now the distnce of the gravity center will be calculated to the
// five anchor points and the smallest will be chosen.
std::array<double, 5> dists;
dists[0] = pl::distance(minc, cc);
dists[1] = pl::distance(maxc, cc);
dists[2] = pl::distance(ibb.center(), cc);
dists[3] = pl::distance(top_left, cc);
dists[4] = pl::distance(bottom_right, cc);
auto dist = *(std::min_element(dists.begin(), dists.end())) / norm;
// Density is the pack density: how big is the arranged pile
auto density = std::sqrt(fullbb.width()*fullbb.height()) / norm;
// The score is a weighted sum of the distance from pile center
// and the pile size
score = GRAVITY_RATIO * dist + DENSITY_RATIO * density;
} else if(itemnormarea < BIG_ITEM_TRESHOLD && bigs.empty()) {
// If there are no big items, only small, we should consider the
// density here as well to not get silly results
auto bindist = pl::distance(ibb.center(), bin.center()) / norm;
auto density = std::sqrt(fullbb.width()*fullbb.height()) / norm;
score = GRAVITY_RATIO * bindist + DENSITY_RATIO * density;
} else {
// Here there are the small items that should be placed around the
// already processed bigger items.
// No need to play around with the anchor points, the center will be
// just fine for small items
score = pl::distance(ibb.center(), bigbb.center()) / norm;
}
// If it does not fit into the print bed we will beat it
// with a large penality. If we would not do this, there would be only
// one big pile that doesn't care whether it fits onto the print bed.
if(!NfpPlacer::wouldFit(fullbb, bin)) score = 2*penality - score;
return score;
};
// Create the arranger object
Arranger arranger(bin, min_obj_distance, pcfg, scfg);
// Set the progress indicator for the arranger.
arranger.progressIndicator(progressind);
// Arrange and return the items with their respective indices within the
// input sequence.
auto result = arranger.arrangeIndexed(shapes.begin(), shapes.end());
auto applyResult = [&shapemap](ArrangeResult::value_type& group,
Coord batch_offset)
{
for(auto& r : group) {
auto idx = r.first; // get the original item index
Item& item = r.second; // get the item itself
// Get the model instance from the shapemap using the index
ModelInstance *inst_ptr = shapemap[idx].first;
// Get the tranformation data from the item object and scale it
// appropriately
auto off = item.translation();
Radians rot = item.rotation();
Pointf foff(off.X*SCALING_FACTOR + batch_offset,
off.Y*SCALING_FACTOR);
// write the tranformation data into the model instance
inst_ptr->rotation = rot;
inst_ptr->offset = foff;
}
};
if(first_bin_only) {
applyResult(result.front(), 0);
} else {
const auto STRIDE_PADDING = 1.2;
Coord stride = static_cast<Coord>(STRIDE_PADDING*
bin.width()*SCALING_FACTOR);
Coord batch_offset = 0;
for(auto& group : result) {
applyResult(group, batch_offset);
// Only the first pack group can be placed onto the print bed. The
// other objects which could not fit will be placed next to the
// print bed
batch_offset += stride;
}
}
for(auto objptr : model.objects) objptr->invalidate_bounding_box();
return ret && result.size() == 1;
}
}
}
#endif // MODELARRANGE_HPP