WIP: smarter transparent polygon sorter

MRPT · Sep 18, 2024 · f234cee · f234cee
1 parent fb7ec66
commit f234cee
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Showing 2 changed files with 63 additions and 2 deletions.
diff --git a/libs/opengl/include/mrpt/opengl/CAssimpModel.h b/libs/opengl/include/mrpt/opengl/CAssimpModel.h
@@ -120,6 +120,13 @@ class CAssimpModel :
 
   mrpt::math::TBoundingBoxf internalBoundingBoxLocal() const override;
 
+  /** Enable (or disable if set to .0f) a feature in which textured triangles
+   *  are split into different renderizable smaller objects.
+   *  This is required only for semitransparent objects with overlaping regions.
+   */
+  void split_triangles_rendering_bbox(const float bbox_size = 1.0f);
+  float split_triangles_rendering_bbox() const { return m_split_triangles_rendering_bbox; }
+
   struct TInfoPerTexture
   {
     // indices in \a m_texturedObjects. string::npos for non-initialized
@@ -152,6 +159,7 @@ class CAssimpModel :
   mutable std::vector<CSetOfTexturedTriangles::Ptr> m_texturedObjects;
   bool m_verboseLoad = false;
   bool m_ignoreMaterialColor = false;
+  float m_split_triangles_rendering_bbox = .0f;
 
   void recursive_render(
       const aiScene* sc,

diff --git a/libs/opengl/src/CAssimpModel.cpp b/libs/opengl/src/CAssimpModel.cpp
@@ -33,6 +33,7 @@
 #endif
 
 #include <mrpt/core/lock_helper.h>
+#include <mrpt/core/round.h>
 #include <mrpt/opengl/opengl_api.h>
 #include <mrpt/serialization/CArchive.h>
 #include <mrpt/system/filesystem.h>
@@ -273,8 +274,49 @@ void CAssimpModel::onUpdateBuffers_all()
 
   process_textures(m_assimp_scene->scene);
 
+  // Model -> 3D primitives:
   const auto transf = mrpt::poses::CPose3D();
   recursive_render(m_assimp_scene->scene, m_assimp_scene->scene->mRootNode, transf, re);
+
+  // Handle split:
+  if (m_split_triangles_rendering_bbox > .0f)
+  {
+    const float voxel = m_split_triangles_rendering_bbox;
+
+    auto& cache = internal::TexturesCache::Instance();
+
+    ASSERT_EQUAL_(m_texturedObjects.size(), m_textureIdMap.size());
+    const std::vector<CSetOfTexturedTriangles::Ptr> origTexturedObjects = m_texturedObjects;
+    m_texturedObjects.clear();
+
+    std::unordered_map<int64_t, CSetOfTexturedTriangles::Ptr> newTextObjs;
+
+    for (size_t textId = 0; textId < m_textureIdMap.size(); textId++)
+    {
+      const auto& glTris = origTexturedObjects.at(textId);
+      const std::vector<mrpt::opengl::TTriangle>& iTris = glTris->shaderTexturedTrianglesBuffer();
+      for (const auto& t : iTris)
+      {
+        const auto midPt = 0.333f * (t.vertices[0].xyzrgba.pt + t.vertices[1].xyzrgba.pt +
+                                     t.vertices[2].xyzrgba.pt);
+        // hash for "voxels":
+        const int64_t vxlCoord = mrpt::round(midPt.x / voxel) +          //
+                                 mrpt::round(midPt.y / voxel) * 10000 +  //
+                                 mrpt::round(midPt.z / voxel) * 10000000;
+
+        auto& trgObj = newTextObjs[vxlCoord];
+        if (!trgObj)
+        {
+          // Create
+          // copy texture
+        }
+        // Add triangle:
+      }
+    }
+
+    // replace list of objects
+  }
+
 #endif
 }
 
@@ -297,14 +339,15 @@ void CAssimpModel::enqueueForRenderRecursive(
   mrpt::opengl::enqueueForRendering(lst, state, rq, wholeInView, is1stShadowMapPass);
 }
 
-uint8_t CAssimpModel::serializeGetVersion() const { return 2; }
+uint8_t CAssimpModel::serializeGetVersion() const { return 3; }
 void CAssimpModel::serializeTo(mrpt::serialization::CArchive& out) const
 {
   writeToStreamRender(out);
 #if (MRPT_HAS_OPENGL_GLUT || MRPT_HAS_EGL) && MRPT_HAS_ASSIMP
   const bool empty = m_assimp_scene->scene == nullptr;
   out << empty;
-  out << m_modelPath;  // v2
+  out << m_modelPath;                       // v2
+  out << m_split_triangles_rendering_bbox;  // v3
   if (!empty)
   {
 #if 0
@@ -348,6 +391,8 @@ void CAssimpModel::serializeFrom(mrpt::serialization::CArchive& in, uint8_t vers
       {
         const bool empty = in.ReadAs<bool>();
         in >> m_modelPath;
+        if (version >= 3) in >> m_split_triangles_rendering_bbox;
+
         if (!empty)
         {
           const auto blobSize = in.ReadAs<uint32_t>();
@@ -460,6 +505,14 @@ auto CAssimpModel::internalBoundingBoxLocal() const -> mrpt::math::TBoundingBoxf
   return mrpt::math::TBoundingBoxf::FromUnsortedPoints(m_bbox_min, m_bbox_max);
 }
 
+void CAssimpModel::split_triangles_rendering_bbox(const float bbox_size)
+{
+  m_split_triangles_rendering_bbox = bbox_size;
+
+  CRenderizable::notifyChange();
+  after_load_model();
+}
+
 bool CAssimpModel::traceRay(
     [[maybe_unused]] const mrpt::poses::CPose3D& o, [[maybe_unused]] double& dist) const
 {