Improve parameterization for thin surfaces

CHANGELOGS.md

@@ -4,6 +4,7 @@
 - Add edge scaling setting for generating low poly 
 - Add rough progress reporting (Windows only) 
 - Generate quad dominated mesh 
+- Improve parameterization for thin surfaces 
 
 1.0.0-beta.2
 - Fix holes 

autoremesher.pro

@@ -190,6 +190,9 @@ HEADERS += src/AutoRemesher/positionkey.h
 SOURCES += src/AutoRemesher/meshseparator.cpp
 HEADERS += src/AutoRemesher/meshseparator.h
 
+SOURCES += src/AutoRemesher/relativeheight.cpp
+HEADERS += src/AutoRemesher/relativeheight.h
+
 INCLUDEPATH += thirdparty/openvdb/openvdb-7.0.0
 INCLUDEPATH += thirdparty/openexr/openexr-2.4.1
 unix {

include/AutoRemesher/RelativeHeight

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2020 Jeremy HU <jeremy-at-dust3d dot org>. All rights reserved. 
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "../src/AutoRemesher/relativeheight.h"

src/AutoRemesher/parameterizer.cpp

@@ -21,6 +21,7 @@
 #include <exploragram/hexdom/quad_cover.h>
 #include <geogram/mesh/mesh_io.h>
 #include <geogram/mesh/mesh_frame_field.h>
+#include <AutoRemesher/RelativeHeight>
 #include <unordered_map>
 #include <unordered_set>
 
@@ -43,6 +44,115 @@ bool Parameterizer::parameterize()
  fclose(fp);
  }
 #endif
+
+ RelativeHeight relativeHeight(m_vertices, m_triangles);
+ relativeHeight.calculate();
+ std::vector<double> *vertexRelativeHeights = relativeHeight.takeVertexRelativeHeights();
+ std::vector<Vector3> *vertexNormals = relativeHeight.takeVertexNormals();
+ std::map<size_t, std::vector<size_t>> *faceAroundVertexMap = relativeHeight.takeFaceAroundVertexMap();
+#if AUTO_REMESHER_DEV
+ {
+ FILE *fp = fopen("debug-relativeheights.ply", "wb");
+ fprintf(fp, "ply\n");
+ fprintf(fp, "format ascii 1.0\n");
+ fprintf(fp, "element vertex %zu\n", m_vertices->size());
+ fprintf(fp, "property float x\n");
+ fprintf(fp, "property float y\n");
+ fprintf(fp, "property float z\n");
+ fprintf(fp, "property uchar red\n");
+ fprintf(fp, "property uchar green\n");
+ fprintf(fp, "property uchar blue\n");
+ fprintf(fp, "element face %zu\n", m_triangles->size());
+ fprintf(fp, "property list uchar uint vertex_indices\n");
+ fprintf(fp, "end_header\n");
+ for (size_t vertexIndex = 0; vertexIndex < m_vertices->size(); ++vertexIndex) {
+ const auto &vertex = (*m_vertices)[vertexIndex];
+ int r = 255 * (*vertexRelativeHeights)[vertexIndex];
+ if (r >= 0) {
+ fprintf(fp, "%f %f %f %d %d %d\n", 
+ vertex.x(), vertex.y(), vertex.z(),
+ r, 0, 0);
+ } else {
+ fprintf(fp, "%f %f %f %d %d %d\n", 
+ vertex.x(), vertex.y(), vertex.z(),
+ 0, r, 0);
+ }
+ }
+ for (const auto &it: *m_triangles) {
+ fprintf(fp, "3 %zu %zu %zu\n",
+ it[0], it[1], it[2]);
+ }
+ fclose(fp);
+ }
+#endif
+ double averageEdgeLength = relativeHeight.averageEdgeLength();
+ std::vector<Vector3> deformedVertices = *m_vertices;
+ for (size_t i = 0; i < deformedVertices.size(); ++i) {
+ const auto &height = (*vertexRelativeHeights)[i];
+ if (height <= 0)
+ continue;
+ deformedVertices[i] += (*vertexNormals)[i] * averageEdgeLength;
+ }
+ int deformRound = 2;
+ while (--deformRound >= 0) {
+ std::vector<Vector3> newPositions = deformedVertices;
+ for (size_t i = 0; i < deformedVertices.size(); ++i) {
+ const auto &height = (*vertexRelativeHeights)[i];
+ if (height <= 0)
+ continue;
+ Vector3 position = deformedVertices[i];
+ size_t vertexCount = 1;
+ for (const auto &face: (*faceAroundVertexMap)[i]) {
+ for (const auto &it: (*m_triangles)[face]) {
+ position += deformedVertices[it];
+ ++vertexCount;
+ }
+ }
+ newPositions[i] = position / vertexCount;
+ }
+ deformedVertices = newPositions;
+ }
+#if AUTO_REMESHER_DEV
+ {
+ FILE *fp = fopen("debug-relativeheights-deformed.ply", "wb");
+ fprintf(fp, "ply\n");
+ fprintf(fp, "format ascii 1.0\n");
+ fprintf(fp, "element vertex %zu\n", deformedVertices.size());
+ fprintf(fp, "property float x\n");
+ fprintf(fp, "property float y\n");
+ fprintf(fp, "property float z\n");
+ fprintf(fp, "property uchar red\n");
+ fprintf(fp, "property uchar green\n");
+ fprintf(fp, "property uchar blue\n");
+ fprintf(fp, "element face %zu\n", m_triangles->size());
+ fprintf(fp, "property list uchar uint vertex_indices\n");
+ fprintf(fp, "end_header\n");
+ for (size_t vertexIndex = 0; vertexIndex < deformedVertices.size(); ++vertexIndex) {
+ const auto &vertex = deformedVertices[vertexIndex];
+ int r = 255 * (*vertexRelativeHeights)[vertexIndex];
+ if (r >= 0) {
+ fprintf(fp, "%f %f %f %d %d %d\n", 
+ vertex.x(), vertex.y(), vertex.z(),
+ r, 0, 0);
+ } else {
+ fprintf(fp, "%f %f %f %d %d %d\n", 
+ vertex.x(), vertex.y(), vertex.z(),
+ 0, r, 0);
+ }
+ }
+ for (const auto &it: *m_triangles) {
+ fprintf(fp, "3 %zu %zu %zu\n",
+ it[0], it[1], it[2]);
+ }
+ fclose(fp);
+ }
+#endif
+ delete vertexRelativeHeights;
+ vertexRelativeHeights = nullptr;
+ delete vertexNormals;
+ vertexNormals = nullptr;
+ delete faceAroundVertexMap;
+ faceAroundVertexMap = nullptr;
 
  auto makeMesh = [](GEO::Mesh &M, const std::vector<Vector3> &vertices, const std::vector<std::vector<size_t>> &triangles) {
  M.vertices.set_dimension(3);
@@ -77,15 +187,18 @@ bool Parameterizer::parameterize()
  };
 
  GEO::Mesh M;
- makeMesh(M, *m_vertices, *m_triangles);
+ makeMesh(M, deformedVertices, *m_triangles);
 
  GEO::Attribute<GEO::vec3> B(M.facets.attributes(), "B");
  if (nullptr == m_triangleFieldVectors) {
+ GEO::Mesh originalM;
+ makeMesh(originalM, *m_vertices, *m_triangles);
+
  GEO::FrameField FF;
  FF.set_use_spatial_search(false);
- FF.create_from_surface_mesh(M, false, 45);
+ FF.create_from_surface_mesh(originalM, false, 45);
  const auto &frames = FF.frames();
- for (GEO::index_t f: M.facets) {
+ for (GEO::index_t f: originalM.facets) {
  B[f] = GEO::vec3(
  frames[9*f+0],
  frames[9*f+1],