backlight in gl

hello,

I am trying to add a simple backlight effect on multiple jit.gl objects. I tried to make planes with same coordinates as sphere objects, and try to add transparent gradient to this planes.
1. I dont't know why, when I make one plane with messages position, scale, color... it works, but when I try to make it with matrix doesn't , when I set @matrixoutput to gridshape the plane disappears.
2. I saw that when I connect matrix to second gridshape(with planes)  it speds more CPU, often max stucks.
3. Is there a more elegant way to do this?:)

can anyone help?