message: Have grid store ranges, not majorants
diff: @@ -115,7 +115,7 @@ struct uniform_grid
  void build(::volume<Mode> const& vol, vec3i num_cells, aabb const& world_bounds)
  {
  dims = num_cells;
  - majorants.resize(dims.x * size_t(dims.y) * dims.z, 0.f);
  + value_ranges.resize(dims.x * size_t(dims.y) * dims.z, { -FLT_MAX, FLT_MAX });
  vec3 world_size = world_bounds.size();
  // We try to use very fine sampling to make sure that
  @@ -168,7 +168,8 @@ struct uniform_grid
  size_t index = linear_index(cell.x, cell.y, cell.z);
  - majorants[index] = max(majorants[index], extinction);
  + value_ranges[index].x = min(value_ranges[index].x, extinction);
  + value_ranges[index].y = max(value_ranges[index].y, extinction);
  }
  }
  }
  @@ -177,7 +178,7 @@ struct uniform_grid
  }
  }
  - std::vector<float> majorants;
  + std::vector<vec2> value_ranges;
  vec3i dims;
  };
  