Hologram emitter effect only using shader (2D on single triangle)

I want to make hologram emitter effect. I have mesh of one triangle with V shape. I need to emit n number of lines from base (bottom of triangle) which will slowly fade away (different for each line).

Reason why I want to do it in shader (and not using texture) is that I want to "update" it every frame.

The effect should be same as on this image but 2D (if I ever want to change it to 2D then I just need to add more triangles). It will be good if there will be more lines (less transparency) in middle of the emitter.

This will be used for floating billboard with emitter on ground.