Merge pull request #335 from CesiumGS/unconditional-refine

Fixed external tilesets not loading when frustum culling was disabled

CHANGES.md

@@ -5,6 +5,7 @@
 ##### Fixes :wrench:
 
 - Fixed a bug introduced in v0.7.0 where Bing credits were not being collected.
+- Fixed a bug where disabling frustum culling caused external tilesets to not load.
 
 ### v0.7.0 - 2021-09-01
 

Cesium3DTilesSelection/include/Cesium3DTilesSelection/Tile.h

@@ -12,8 +12,10 @@
 #include "CesiumGeospatial/Projection.h"
 #include "CesiumUtility/DoublyLinkedList.h"
 #include <atomic>
+#include <glm/common.hpp>
 #include <glm/mat4x4.hpp>
 #include <gsl/span>
+#include <limits>
 #include <memory>
 #include <optional>
 #include <string>
@@ -294,6 +296,29 @@ class CESIUM3DTILESSELECTION_API Tile final {
     this->_geometricError = value;
   }
 
+  /**
+   * @brief Returns whether to unconditionally refine this tile.
+   *
+   * This is useful in cases such as with external tilesets, where instead of a
+   * tile having any content, it points to an external tileset's root. So the
+   * tile always needs to be refined otherwise the external tileset will not be
+   * displayed.
+   *
+   * @return Whether to uncoditionally refine this tile.
+   */
+  bool getUnconditionallyRefine() const noexcept {
+    return glm::isinf(this->_geometricError);
+  }
+
+  /**
+   * @brief Marks that this tile should be unconditionally refined.
+   *
+   * This function is not supposed to be called by clients.
+   */
+  void setUnconditionallyRefine() noexcept {
+    this->_geometricError = std::numeric_limits<double>::infinity();
+  }
+
   /**
    * @brief The refinement strategy of this tile.
    *

Cesium3DTilesSelection/src/Tile.cpp

@@ -629,12 +629,12 @@ void Tile::update(
             std::move(this->_pContent->pNewTileContext));
       }
 
-      // If this tile has no model, set its geometric error very high so we
-      // refine past it. Note that "no" model is different from having a model,
-      // but it is blank. In the latter case, we'll happily render nothing in
-      // the space of this tile, which is sometimes useful.
+      // If this tile has no model, we want to unconditionally refine past it.
+      // Note that "no" model is different from having a model, but it is blank.
+      // In the latter case, we'll happily render nothing in the space of this
+      // tile, which is sometimes useful.
       if (!this->_pContent->model) {
-        this->setGeometricError(999999999.0);
+        this->setUnconditionallyRefine();
       }
 
       // A new and improved bounding volume.

Cesium3DTilesSelection/src/Tileset.cpp

@@ -1682,11 +1682,13 @@ Tileset::TraversalDetails Tileset::_visitTile(
     return _renderLeaf(frameState, tile, distances, result);
   }
 
+  bool unconditionallyRefine = tile.getUnconditionallyRefine();
   bool meetsSse = _meetsSse(frameState.frustums, tile, distances, culled);
   bool waitingForChildren =
       _queueLoadOfChildrenRequiredForRefinement(frameState, tile, distances);
 
-  if (meetsSse || ancestorMeetsSse || waitingForChildren) {
+  if (!unconditionallyRefine &&
+      (meetsSse || ancestorMeetsSse || waitingForChildren)) {
     // This tile (or an ancestor) is the one we want to render this frame, but
     // we'll do different things depending on the state of this tile and on what
     // we did _last_ frame.

Cesium3DTilesSelection/test/TestTilesetSelectionAlgorithm.cpp

@@ -628,9 +628,8 @@ TEST_CASE("Test additive refinement") {
             "tileset3/tileset3.json") {
           REQUIRE(doesTileMeetSSE(viewState, child, tileset));
         } else {
-          // external tileset has always geometric error over 999999, so it
-          // won't meet sse
-          REQUIRE(!doesTileMeetSSE(viewState, child, tileset));
+          // external tilesets get unconditionally refined
+          REQUIRE(root->getUnconditionallyRefine());
 
           // expect the children to meet sse and begin loading the content
           REQUIRE(child.getChildren().size() == 1);