Flip heightmap's Y position on Ogre 2 and add sanity checks for NaN

Migration.md

@@ -5,6 +5,12 @@ Deprecated code produces compile-time warnings. These warning serve as
 notification to users that their code should be upgraded. The next major
 release will remove the deprecated code.
 
+## Ignition Rendering 6.0.1 to 6.1.0
+
+### Modifications
+
+1. Ogre 2 heightmaps: the Y position sign was flipped
+
 ## Ignition Rendering 5.x to 6.x
 
 ### Modifications

examples/heightmap/Main.cc

@@ -152,7 +152,7 @@ void buildScene(ScenePtr _scene)
  textureC2.SetDiffuse("../media/dirt_diffusespecular.png");
  textureC2.SetNormal("../media/flat_normal.png");
  desc2.AddTexture(textureC2);
- desc2.SetPosition({30, 0, 0});
+ desc2.SetPosition({30, 10, 0});
  auto heightmapGeom2 = _scene->CreateHeightmap(desc2);
 
  auto vis2 = _scene->CreateVisual();

ogre/src/OgreHeightmap.cc

@@ -491,7 +491,14 @@ void OgreHeightmap::Init()
  for (unsigned int x = 0; x < vertSize; ++x)
  {
  int index = (vertSize - y - 1) * vertSize + x;
- this->dataPtr->heights.push_back(lookup[index] - minElevation);
+
+ // Sanity check in case we get NaNs from ign-common, this prevents a crash
+ // in Ogre
+ auto value = lookup[index];
+ if (!std::isfinite(value))
+ value = minElevation;
+
+ this->dataPtr->heights.push_back(value - minElevation);
  }
  }
 

ogre2/src/Ogre2Heightmap.cc

@@ -158,17 +158,35 @@ void Ogre2Heightmap::Init()
  // Obtain min and max elevation and bring everything to range [0; 1]
  // Terra should support non-normalized ranges but there are a couple
  // bugs preventing that, so it's just easier to normalize the data
- float minElevation = 0.0;
- float maxElevation = 0.0;
+ double minElevation = this->descriptor.Data()->MinElevation();
+ double maxElevation = this->descriptor.Data()->MaxElevation();
+
+ // Sanity check
+ if (minElevation >= maxElevation)
+ {
+ ignerr << "Internal error: min elevation [" << minElevation
+ << "] >= max elevation [" << maxElevation << "]" << std::endl;
+ return;
+ }
 
  for (unsigned int y = 0; y < newWidth; ++y)
  {
  for (unsigned int x = 0; x < newWidth; ++x)
  {
  const size_t index = y * srcWidth + x;
- const float heightVal = lookup[index];
- minElevation = std::min(minElevation, heightVal);
- maxElevation = std::max(maxElevation, heightVal);
+ float heightVal = lookup[index];
+
+ // Sanity check in case we get NaNs from ign-common, this prevents a crash
+ // in Ogre
+ if (!std::isfinite(heightVal))
+ heightVal = minElevation;
+
+ if (heightVal < minElevation || heightVal > maxElevation)
+ {
+ ignerr << "Internal error: height [" << heightVal
+ << "] is out of bounds [" << minElevation << " / "
+ << maxElevation << "]" << std::endl;
+ }
  this->dataPtr->heights.push_back(heightVal);
  }
  }
@@ -208,9 +226,10 @@ void Ogre2Heightmap::Init()
  const math::Vector3d newSize = this->descriptor.Size() *
  math::Vector3d(1.0, 1.0, heightDiff);
 
+ // The position's Y sign ends up flipped
  math::Vector3d center(
  this->descriptor.Position().X(),
- this->descriptor.Position().Y(),
+ -this->descriptor.Position().Y(),
  this->descriptor.Position().Z() + newSize.Z() * 0.5 + minElevation);
 
  Ogre::Root *ogreRoot = Ogre2RenderEngine::Instance()->OgreRoot();