ID:2282754
 
(See the best response by Ter13.)
I need to draw blackness cover over my images which are peeking out of tile bounds.

How do i do that? Is there any blackness plane or layer variables?

Image of object made of multiple overlays. Object and all the overlays have appearance_flags and plane set to 0.

Example of my trouble: https://i.imgur.com/9HIetvi.png
Best response
Look up TILE_BOUND. It's an appearance flag that makes objects only consider their root turf for visibility calculations.

Here's a link to the reference on the subject:

http://www.byond.com/docs/ref/info.html#/atom/var/ appearance_flags

Object and all the overlays have appearance_flags and plane set to 0.

This is the problem. appearance_flags of 0 means that TILE_BOUND is off.

If that doesn't fully fix it, you can try using the SEE_BLACKNESS flag for the mob.sight variable, which will render darkness to plane 0. This means that you will probably want objects that should be covered by darkness on planes -1 and below.
SEE_BLACKNESS did it!

Many thanks!