A simple fix might be to add a check for this condition in ll-1.sh and use the output of the ls command to generate the input for ll-2.sh when nothing is provided to ll1-sh.

The script ll-1.sh simply passes each of its parameters in turn to the script ll-2.sh and ll-2.sh

SH lighting is very low frequency. You can't have sharp lighting transitions with SH lights. They are also only affecting the diffuse lighting (too low frequency for specular highlights).