From 2e9f0d6eaffb05399029df1a6c437ce480506bec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Hejl?= <hejl.lukas@gmail.com>
Date: Mon, 3 May 2021 20:56:39 +0200
Subject: [PATCH] Fixed a few cases of missing colored segments in MMU
segmentation.
Occasionally, some input polygons contained self-intersections that caused problems with Voronoi diagrams and consequently with the extraction of colored segments by function extract_colored_segments.
Also, occasionally input polygons contained several points very close together (distance between points is 1 or so). Such close points sometimes caused that the Voronoi diagram has self-intersecting edges around these vertices. This consequently leads to issues with the extraction of colored segments by function extract_colored_segments.
---
src/libslic3r/MultiMaterialSegmentation.cpp | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/libslic3r/MultiMaterialSegmentation.cpp b/src/libslic3r/MultiMaterialSegmentation.cpp
index 1ed08ef4b..011851614 100644
--- a/src/libslic3r/MultiMaterialSegmentation.cpp
+++ b/src/libslic3r/MultiMaterialSegmentation.cpp
@@ -1370,7 +1370,14 @@ std::vector<std::vector<std::pair<ExPolygon, size_t>>> multi_material_segmentati
ex_polygons = union_ex(ex_polygons);
// Remove all expolygons and holes with an area less than 0.01mm^2
remove_small_and_small_holes(ex_polygons, Slic3r::sqr(scale_(0.1f)));
- input_polygons[layer_idx] = to_polygons(union_ex(offset_ex(ex_polygons, -SCALED_EPSILON)));
+ // Occasionally, some input polygons contained self-intersections that caused problems with Voronoi diagrams
+ // and consequently with the extraction of colored segments by function extract_colored_segments.
+ // Calling simplify_polygons removes these self-intersections.
+ // Also, occasionally input polygons contained several points very close together (distance between points is 1 or so).
+ // Such close points sometimes caused that the Voronoi diagram has self-intersecting edges around these vertices.
+ // This consequently leads to issues with the extraction of colored segments by function extract_colored_segments.
+ // Calling expolygons_simplify fixed these issues.
+ input_polygons[layer_idx] = simplify_polygons(to_polygons(expolygons_simplify(offset_ex(ex_polygons, -SCALED_EPSILON), SCALED_EPSILON)));
}
for (size_t layer_idx = 0; layer_idx < layers.size(); ++layer_idx) {