@ustk the main function of a fragment shader is stateless because it will be executed simultaneously for every pixel on the GPU which is an absurd fact to wrap your head around at the beginning.
In addition, it is currently impossible to add the lower velocity cross fade via the GUI or via manually editing the sample map xml. When adding the "LowerVelocityXFade" values in the XML and loading it into the GUI, they are wiped out.
I built an updated develop branch on Nov 1st....I used the prepocessor HISE_COMPLAIN_ABOUT_ILLEGAL_BUFFER_SIZE=0 on the most recent export so this hopefully should solve.
@tomekslesicki The problem is that the XFade starts multiple voices for the same note which the SynthesiserGroup does not handle well and there is not an easy fix for this - the synthesizer group is a very specialized use case for adding FM & unisono on a voice level and isn't suited to handle multimic voices or Fade samples very well.