no, this shouldn't be the case. Try setting sc_mtl_pp_HBlur.skill1 = 0.1; before calling sc_ppAdd
Thanks, this will probably do it!
I'm glad You found motion blur idea useful Mirror-shader would be superb, but actually it is very hard to make it working, I spent many days still no luck. There is horizontal mirror shader in default 3dgs shaders file, but when it comes to vertical - many problems arise up from nowhere ^_^