Please can we see code example of how to do this!
Keep in mind this is crude. I don't actually like that the plane master has to be done as an image, but I haven't figured out a good alternative yet. (It's not a HUD object, although I plan to make a change where it could be added as one.)
image/planemaster
plane = 2
blend_mode = BLEND_MULTIPLY
appearance_flags = PLANE_MASTER | NO_CLIENT_COLOR
color = list(null,null,null,null,"#555")
image/spotlight
plane = 2
blend_mode = BLEND_ADD
icon = 'spotlight.dmi'
pixel_x = -32
pixel_y = -32
mob/Login()
..()
src << new/image/planemaster(loc=src)
overlays += /image/spotlight
obj/pyramid
overlays = list(/image/spotlight)
The planemaster object has a constant ambient light that's added to the plane before it gets blended, and the spotlight image is just a white 96x96 circle.
https://gist.github.com/PJB3005/ad9285c2fb344caa1926
I'd embed an image but since it's all alphas that doesn't really work: have this instead.
https://imgur.com/2oWnNDo
(it's from a confused time where my guess at how TobbaLights works was ways off, but it may become a reality now in 510)
It does require https://gitlab.com/N3X15/ByondTools though (the dependencies for BYONDTools can all be installed through pip, numpy might be a nuisance though).