How to create my own ktx2

Is there hand by hand guide to create ktx2 ?

  • I’m a js developer and don’t know how to build the Khronos glTF IBL Sampler, unable to solve endless error in cmake.
  • I create a ktx from a hdr with filament cmgen, and convert it to ktx2 using ktx2ktx2, but Cesium gives me this error:
    Cannot read property ‘positiveX’ of undefined at OctahedralProjectedCubeMap.update
  • Then I create a ktx2 from six pngs using toktx, then Cesium gives me:
    uniformMap[] is not a function at ShaderProgram._setUniforms