Index: nanovdb/nanovdb/NanoVDB.h
===================================================================
--- a/nanovdb/nanovdb/NanoVDB.h	(revision 62751)
+++ b/nanovdb/nanovdb/NanoVDB.h	(working copy)
@@ -152,8 +152,8 @@
 
 #endif // __CUDACC_RTC__
 
-#ifdef __CUDACC__
-// Only define __hostdev__ when using NVIDIA CUDA compiler
+#if defined(__CUDACC__) || defined(__HIP__)
+// Only define __hostdev__ when using NVIDIA CUDA or HIP compiler
 #define __hostdev__ __host__ __device__
 #else
 #define __hostdev__
@@ -461,7 +461,7 @@
 /// Maximum floating-point values
 template<typename T>
 struct Maximum;
-#ifdef __CUDA_ARCH__
+#if defined(__CUDA_ARCH__) || defined(__HIP__)
 template<>
 struct Maximum<int>
 {
@@ -1006,10 +1006,10 @@
 using Vec3i = Vec3<int>;
 
 /// @brief Return a single precision floating-point vector of this coordinate
-Vec3f Coord::asVec3s() const { return Vec3f(float(mVec[0]), float(mVec[1]), float(mVec[2])); }
+inline __hostdev__ Vec3f Coord::asVec3s() const { return Vec3f(float(mVec[0]), float(mVec[1]), float(mVec[2])); }
 
 /// @brief Return a double precision floating-point vector of this coordinate
-Vec3d Coord::asVec3d() const { return Vec3d(double(mVec[0]), double(mVec[1]), double(mVec[2])); }
+inline __hostdev__ Vec3d Coord::asVec3d() const { return Vec3d(double(mVec[0]), double(mVec[1]), double(mVec[2])); }
 
 // ----------------------------> Vec4 <--------------------------------------
 
@@ -1820,7 +1820,7 @@
 }; // Map
 
 template<typename Mat4T>
-void Map::set(const Mat4T& mat, const Mat4T& invMat, double taper)
+__hostdev__ void Map::set(const Mat4T& mat, const Mat4T& invMat, double taper)
 {
     float * mf = mMatF, *vf = mVecF;
     float*  mif = mInvMatF;
@@ -2170,7 +2170,7 @@
 }; // Class Grid
 
 template<typename TreeT>
-int Grid<TreeT>::findBlindDataForSemantic(GridBlindDataSemantic semantic) const
+__hostdev__ int Grid<TreeT>::findBlindDataForSemantic(GridBlindDataSemantic semantic) const
 {
     for (uint32_t i = 0, n = blindDataCount(); i < n; ++i)
         if (blindMetaData(i).mSemantic == semantic)
@@ -2328,7 +2328,7 @@
 }; // Tree class
 
 template<typename RootT>
-void Tree<RootT>::extrema(ValueType& min, ValueType& max) const
+__hostdev__ void Tree<RootT>::extrema(ValueType& min, ValueType& max) const
 {
     min = this->root().valueMin();
     max = this->root().valueMax();
@@ -2336,7 +2336,7 @@
 
 template<typename RootT>
 template<typename NodeT>
-const NodeT* Tree<RootT>::getNode(uint32_t i) const
+__hostdev__ const NodeT* Tree<RootT>::getNode(uint32_t i) const
 {
     static_assert(is_same<TreeNodeT<NodeT::LEVEL>, NodeT>::value, "Tree::getNode: unvalid node type");
     NANOVDB_ASSERT(i < DataType::mCount[NodeT::LEVEL]);
@@ -2345,7 +2345,7 @@
 
 template<typename RootT>
 template<int LEVEL>
-const typename TreeNode<Tree<RootT>, LEVEL>::type* Tree<RootT>::getNode(uint32_t i) const
+__hostdev__ const typename TreeNode<Tree<RootT>, LEVEL>::type* Tree<RootT>::getNode(uint32_t i) const
 {
     NANOVDB_ASSERT(i < DataType::mCount[LEVEL]);
     return reinterpret_cast<const TreeNodeT<LEVEL>*>(reinterpret_cast<const uint8_t*>(this) + DataType::mBytes[LEVEL]) + i;
@@ -2353,7 +2353,7 @@
 
 template<typename RootT>
 template<typename NodeT>
-NodeT* Tree<RootT>::getNode(uint32_t i)
+__hostdev__ NodeT* Tree<RootT>::getNode(uint32_t i)
 {
     static_assert(is_same<TreeNodeT<NodeT::LEVEL>, NodeT>::value, "Tree::getNode: invalid node type");
     NANOVDB_ASSERT(i < DataType::mCount[NodeT::LEVEL]);
@@ -2362,7 +2362,7 @@
 
 template<typename RootT>
 template<int LEVEL>
-typename TreeNode<Tree<RootT>, LEVEL>::type* Tree<RootT>::getNode(uint32_t i)
+__hostdev__ typename TreeNode<Tree<RootT>, LEVEL>::type* Tree<RootT>::getNode(uint32_t i)
 {
     NANOVDB_ASSERT(i < DataType::mCount[LEVEL]);
     return reinterpret_cast<TreeNodeT<LEVEL>*>(reinterpret_cast<uint8_t*>(this) + DataType::mBytes[LEVEL]) + i;
@@ -2370,7 +2370,7 @@
 
 template<typename RootT>
 template<typename NodeT>
-uint32_t Tree<RootT>::getNodeID(const NodeT& node) const
+__hostdev__ uint32_t Tree<RootT>::getNodeID(const NodeT& node) const
 {
     static_assert(is_same<TreeNodeT<NodeT::LEVEL>, NodeT>::value, "Tree::getNodeID: invalid node type");
     const NodeT* first = reinterpret_cast<const NodeT*>(reinterpret_cast<const uint8_t*>(this) + DataType::mBytes[NodeT::LEVEL]);
@@ -2380,7 +2380,7 @@
 
 template<typename RootT>
 template<typename NodeT>
-uint32_t Tree<RootT>::getLinearOffset(const NodeT& node) const
+__hostdev__ uint32_t Tree<RootT>::getLinearOffset(const NodeT& node) const
 {
     return this->getNodeID(node) + DataType::mPFSum[NodeT::LEVEL];
 }
@@ -3366,7 +3366,7 @@
 }; // LeafNode class
 
 template<typename ValueT, typename CoordT, template<uint32_t> class MaskT, uint32_t LOG2DIM>
-inline void LeafNode<ValueT, CoordT, MaskT, LOG2DIM>::updateBBox()
+inline __hostdev__ void LeafNode<ValueT, CoordT, MaskT, LOG2DIM>::updateBBox()
 {
     static_assert(LOG2DIM == 3, "LeafNode::updateBBox: only supports LOGDIM = 3!");
     if (!this->isActive()) return;
Index: nanovdb/nanovdb/util/SampleFromVoxels.h
===================================================================
--- a/nanovdb/nanovdb/util/SampleFromVoxels.h	(revision 62751)
+++ b/nanovdb/nanovdb/util/SampleFromVoxels.h	(working copy)
@@ -22,7 +22,7 @@
 #define NANOVDB_SAMPLE_FROM_VOXELS_H_HAS_BEEN_INCLUDED
 
 // Only define __hostdev__ when compiling as NVIDIA CUDA
-#ifdef __CUDACC__
+#if defined(__CUDACC__) || defined(__HIP__)
 #define __hostdev__ __host__ __device__
 #else
 #include <cmath> // for floor
@@ -136,7 +136,7 @@
 
 template<typename TreeOrAccT>
 template<typename Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 0, true>::operator()(const Vec3T& xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 0, true>::operator()(const Vec3T& xyz) const
 {
     const CoordT ijk = Round<CoordT>(xyz);
     if (ijk != mPos) {
@@ -147,7 +147,7 @@
 }
 
 template<typename TreeOrAccT>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 0, true>::operator()(const CoordT& ijk) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 0, true>::operator()(const CoordT& ijk) const
 {
     if (ijk != mPos) {
         mPos = ijk;
@@ -158,7 +158,7 @@
 
 template<typename TreeOrAccT>
 template<typename Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 0, false>::operator()(const Vec3T& xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 0, false>::operator()(const Vec3T& xyz) const
 {
     return mAcc.getValue(Round<CoordT>(xyz));
 }
@@ -195,7 +195,7 @@
 }; // TrilinearSamplerBase
 
 template<typename TreeOrAccT>
-void TrilinearSampler<TreeOrAccT>::stencil(CoordT& ijk, ValueT (&v)[2][2][2]) const
+__hostdev__ void TrilinearSampler<TreeOrAccT>::stencil(CoordT& ijk, ValueT (&v)[2][2][2]) const
 {
     v[0][0][0] = mAcc.getValue(ijk); // i, j, k
 
@@ -224,7 +224,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType TrilinearSampler<TreeOrAccT>::sample(const Vec3T<RealT> &uvw, const ValueT (&v)[2][2][2])
+__hostdev__ typename TreeOrAccT::ValueType TrilinearSampler<TreeOrAccT>::sample(const Vec3T<RealT> &uvw, const ValueT (&v)[2][2][2])
 {
 #if 0
   auto lerp = [](ValueT a, ValueT b, ValueT w){ return fma(w, b-a, a); };// = w*(b-a) + a
@@ -239,7 +239,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-Vec3T<typename TreeOrAccT::ValueType> TrilinearSampler<TreeOrAccT>::gradient(const Vec3T<RealT> &uvw, const ValueT (&v)[2][2][2])
+__hostdev__ Vec3T<typename TreeOrAccT::ValueType> TrilinearSampler<TreeOrAccT>::gradient(const Vec3T<RealT> &uvw, const ValueT (&v)[2][2][2])
 {
     static_assert(std::is_floating_point<ValueT>::value, "TrilinearSampler::gradient requires a floating-point type");
 #if 0
@@ -270,7 +270,7 @@
 }
 
 template<typename TreeOrAccT>
-bool TrilinearSampler<TreeOrAccT>::zeroCrossing(const ValueT (&v)[2][2][2])
+__hostdev__ bool TrilinearSampler<TreeOrAccT>::zeroCrossing(const ValueT (&v)[2][2][2])
 {
     static_assert(std::is_floating_point<ValueT>::value, "TrilinearSampler::zeroCrossing requires a floating-point type");
     const bool less = v[0][0][0] < ValueT(0);
@@ -363,7 +363,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, true>::operator()(Vec3T<RealT> xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, true>::operator()(Vec3T<RealT> xyz) const
 {
     this->cache(xyz);
     return BaseT::sample(xyz, mVal);
@@ -370,7 +370,7 @@
 }
 
 template<typename TreeOrAccT>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, true>::operator()(const CoordT &ijk) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, true>::operator()(const CoordT &ijk) const
 {
     return  ijk == mPos ? mVal[0][0][0] : BaseT::mAcc.getValue(ijk);
 }
@@ -377,7 +377,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-Vec3T<typename TreeOrAccT::ValueType> SampleFromVoxels<TreeOrAccT, 1, true>::gradient(Vec3T<RealT> xyz) const
+__hostdev__ Vec3T<typename TreeOrAccT::ValueType> SampleFromVoxels<TreeOrAccT, 1, true>::gradient(Vec3T<RealT> xyz) const
 {
     this->cache(xyz);
     return BaseT::gradient(xyz, mVal);
@@ -393,7 +393,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-void SampleFromVoxels<TreeOrAccT, 1, true>::cache(Vec3T<RealT>& xyz) const
+__hostdev__ void SampleFromVoxels<TreeOrAccT, 1, true>::cache(Vec3T<RealT>& xyz) const
 {
     CoordT ijk = Floor<CoordT>(xyz);
     if (ijk != mPos) {
@@ -406,7 +406,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, false>::operator()(Vec3T<RealT> xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, false>::operator()(Vec3T<RealT> xyz) const
 {
     ValueT val[2][2][2];
     CoordT ijk = Floor<CoordT>(xyz);
@@ -418,7 +418,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, false>::operator()(Vec3T<RealT> xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 1, false>::operator()(Vec3T<RealT> xyz) const
 {
     auto lerp = [](ValueT a, ValueT b, RealT w) { return a + ValueT(w) * (b - a); };
 
@@ -463,7 +463,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-inline Vec3T<typename TreeOrAccT::ValueType> SampleFromVoxels<TreeOrAccT, 1, false>::gradient(Vec3T<RealT> xyz) const
+inline __hostdev__ Vec3T<typename TreeOrAccT::ValueType> SampleFromVoxels<TreeOrAccT, 1, false>::gradient(Vec3T<RealT> xyz) const
 {
     ValueT val[2][2][2];
     CoordT ijk = Floor<CoordT>(xyz);
@@ -473,7 +473,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-bool SampleFromVoxels<TreeOrAccT, 1, false>::zeroCrossing(Vec3T<RealT> xyz) const
+__hostdev__ bool SampleFromVoxels<TreeOrAccT, 1, false>::zeroCrossing(Vec3T<RealT> xyz) const
 {
     ValueT val[2][2][2];
     CoordT ijk = Floor<CoordT>(xyz);
@@ -510,7 +510,7 @@
 }; // TriquadraticSamplerBase
 
 template<typename TreeOrAccT>
-void TriquadraticSampler<TreeOrAccT>::stencil(const CoordT &ijk, ValueT (&v)[3][3][3]) const
+__hostdev__ void TriquadraticSampler<TreeOrAccT>::stencil(const CoordT &ijk, ValueT (&v)[3][3][3]) const
 {
     CoordT p(ijk[0] - 1, 0, 0);
     for (int dx = 0; dx < 3; ++dx, ++p[0]) {
@@ -526,7 +526,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType TriquadraticSampler<TreeOrAccT>::sample(const Vec3T<RealT> &uvw, const ValueT (&v)[3][3][3])
+__hostdev__ typename TreeOrAccT::ValueType TriquadraticSampler<TreeOrAccT>::sample(const Vec3T<RealT> &uvw, const ValueT (&v)[3][3][3])
 {
     auto kernel = [](const ValueT* value, double weight)->ValueT {
         return weight * (weight * (0.5f * (value[0] + value[2]) - value[1]) + 
@@ -545,7 +545,7 @@
 }
 
 template<typename TreeOrAccT>
-bool TriquadraticSampler<TreeOrAccT>::zeroCrossing(const ValueT (&v)[3][3][3])
+__hostdev__ bool TriquadraticSampler<TreeOrAccT>::zeroCrossing(const ValueT (&v)[3][3][3])
 {
     static_assert(std::is_floating_point<ValueT>::value, "TrilinearSampler::zeroCrossing requires a floating-point type");
     const bool less = v[0][0][0] < ValueT(0);
@@ -624,7 +624,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 2, true>::operator()(Vec3T<RealT> xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 2, true>::operator()(Vec3T<RealT> xyz) const
 {
     this->cache(xyz);
     return BaseT::sample(xyz, mVal);
@@ -631,7 +631,7 @@
 }
 
 template<typename TreeOrAccT>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 2, true>::operator()(const CoordT &ijk) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 2, true>::operator()(const CoordT &ijk) const
 {
     return  ijk == mPos ? mVal[1][1][1] : BaseT::mAcc.getValue(ijk);
 }
@@ -646,7 +646,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-void SampleFromVoxels<TreeOrAccT, 2, true>::cache(Vec3T<RealT>& xyz) const
+__hostdev__ void SampleFromVoxels<TreeOrAccT, 2, true>::cache(Vec3T<RealT>& xyz) const
 {
     CoordT ijk = Floor<CoordT>(xyz);
     if (ijk != mPos) {
@@ -657,7 +657,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 2, false>::operator()(Vec3T<RealT> xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 2, false>::operator()(Vec3T<RealT> xyz) const
 {
     ValueT val[3][3][3];
     CoordT ijk = Floor<CoordT>(xyz);
@@ -667,7 +667,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-bool SampleFromVoxels<TreeOrAccT, 2, false>::zeroCrossing(Vec3T<RealT> xyz) const
+__hostdev__ bool SampleFromVoxels<TreeOrAccT, 2, false>::zeroCrossing(Vec3T<RealT> xyz) const
 {
     ValueT val[3][3][3];
     CoordT ijk = Floor<CoordT>(xyz);
@@ -710,7 +710,7 @@
 }; // TricubicSampler
 
 template<typename TreeOrAccT>
-void TricubicSampler<TreeOrAccT>::stencil(const CoordT& ijk, ValueT (&C)[64]) const
+__hostdev__ void TricubicSampler<TreeOrAccT>::stencil(const CoordT& ijk, ValueT (&C)[64]) const
 {
     auto fetch = [&](int i, int j, int k) -> ValueT& { return C[((i + 1) << 4) + ((j + 1) << 2) + k + 1]; };
 
@@ -929,7 +929,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 3, true>::operator()(Vec3T<RealT> xyz) const
+__hostdev__ typename TreeOrAccT::ValueType SampleFromVoxels<TreeOrAccT, 3, true>::operator()(Vec3T<RealT> xyz) const
 {
     this->cache(xyz);
     return BaseT::sample(xyz, mC);
@@ -937,7 +937,7 @@
 
 template<typename TreeOrAccT>
 template<typename RealT, template<typename...> class Vec3T>
-void SampleFromVoxels<TreeOrAccT, 3, true>::cache(Vec3T<RealT>& xyz) const
+__hostdev__ void SampleFromVoxels<TreeOrAccT, 3, true>::cache(Vec3T<RealT>& xyz) const
 {
     CoordT ijk = Floor<CoordT>(xyz);
     if (ijk != mPos) {