Each segment will have about 7 of the ws2812B leds because with a heatsink they have a radius of 1cm and a segment is planned to be 7.5cm long.
Diffusion of light: I plan to either sand the glass or to use a thin paper membrane like wax paper. The interior of each segment is to be covered with foil to reflect the light and mix intensities betterBlocking of light: Currently I have two choices in masking of the light , first isto get a black or reflective decal cut at a store. My second option is to print templates and to spraypaint the glass with them. With painting the glass i could add multiple layers of diffrent colors of paint to ensure little light leaks through. So I will for example paint a layer of white , then black and then white again. The first layer being to match in with the sanded opaque glass , the second to absorb as much light as possible and the third is to reflect light back to the segmenst inne part itself.
Physical dimensions : The sign is planned to be 1.5m long 0.5m high and 5cm deep. The main factor that influences depth is how fast the light of the leds diverge and how fast i can make them diverge.
Interface: The plan is to incorporate a bluetooth module and to send cmd via a cellphone. Ideally the clock should integrate with my phone such that it lights up when i use my phones light and flashes when i should wake up.