[compile error] PCL uses hard-coded path of VTK resulting in failure when cross-compiling

Describe the error

Not finished yet.

We were trying to cross compile our application for aarch64. However

elseif(NOT VTK_DIR AND NOT ANDROID)
set(VTK_DIR "/usr/lib/cmake/vtk-6.3" CACHE PATH "The directory containing VTKConfig.cmake")
endif(PCL_ALL_IN_ONE_INSTALLER AND NOT ANDROID)
To Reproduce

Provide a link to a live example, or an unambiguous set of steps to reproduce this bug. A reproducible example helps to provide faster answers. Custom OS, custom PCL configs or custom build systems make the issue difficult to reproduce.

• Best reproducability: A docker image + code snippets provided here
• Good reproducability: Common Linux OS + default PCL config + code snippets provided here
• Poor reproducability: code snippets

Remember to reproduce the error in a clean rebuild (removing all build objects and starting build from scratch)

Screenshots/Code snippets/Build information

In order to help explain your problem, please consider adding

• screenshots of the GUI issues
• code snippets: syntax for code with correct language highlights
• debugging information:
  • the output of cmake using cmake --debug
  • the failing build command(s) using VERBOSE=1 make, ninja -v or similar
  • steps taken to narrow down the problem

Your Environment (please complete the following information):

• OS: [e.g. Ubuntu 16.04]
• Compiler: [:eg GCC 8.1]
• PCL Version [e.g. 1.10, HEAD] (NB: please ensure you don't have multiple versions available)
• PCL Type: [Installed/Compiled from source]

If PCL was compiled from source or failure in compiling PCL itself:

• GPU, Kinfu, CUDA enabled? Yes/No
• List and Version of dependencies used
• Compilation flags are used

If compiling against PCL:

• Checked CMakeLists.txt for simple errors like missing find_package or target_link_libraries?

• CMakeLists.txt for PCL >= 1.9
• CMakeLists.txt for older versions

Possible Solution

Not obligatory, but suggest a fix/reason for the bug. Feel free to create a PR if you feel comfortable.

Additional context

Add any other context about the problem here.

Start by locating the shown VTK_DIR assignment in the project's CMake configuration and reproduce the cross-compilation failure for aarch64. The issue needs a complete reproduction and environment details; done should mean configuration no longer depends on the hard-coded /usr/lib/cmake/vtk-6.3 path and the clean cross-compile succeeds.