Open VKL v0.11.0

• Introduced API support for multi-attribute volumes, including APIs for sampling multiple attributes simultaneously
  • Initially only structuredRegular and structuredSpherical volume types support multi-attribute data
• Iterator APIs now work on sampler objects rather than volumes, supporting finer-grained configurability
• Observers can now be created for both volume and sampler objects
  • LeafNodeAccess observers must now be created on sampler objects
• Log and error callbacks now support a user pointer
• vdb volume interval iterators:
  • Added support for elementary cell iteration when maxIteratorDepth is set to VKL_VDB_NUM_LEVELS-1
  • Up to 2x faster iteration
• unstructured and particle volume interval iterators:
  • Improved interior empty space skipping behavior
  • Added support for configurable iterator depth via the maxIteratorDepth parameter
• Added support for filter modes in structuredRegular and structuredSpherical volumes
• amr volumes now support method parameter on sampler objects
• Added new interval_iterator_debug renderer in vklExamples to visualize interval iteration behavior
• Hit iterator accuracy improvements for unstructured volumes
• Fixed bugs in amr and vdb volume bounding box computations
• Fixed bug in unstructured volume gradient computations near empty regions
• Minimum ISPC version is now v1.14.1