how lighting work in T2D

#1 You can use an alpha screen overlay sprite - transparent in the center and fade to opaque on the edges. Just load it in the top layer of your scene window.

#2 thanks richard!
but is there any tutorial about it?
I am kind of lost in the new engine

#3 What Richard suggested was using a sprite who's image has an alpha channel and has been edited in an image editor to have some parts more translucent than others. T2D will automatically use the alpha channel and blend the image. If you put it on scene layer 0 and another sprite on scene layer 1, the translucent image on layer 0 will be on top of the layer 1 image. Kinda like what this image shows:


If you're looking for pixel shaders, T2D doesn't have that yet.
Example:

You might be able to achieve a similar look by rotating shadow sprites away from light source sprites but it obviously won't look as realistic.

#4 Thanks!i think what i am looking for is pixel shaders,does TGB have this functions?or its just never shown up in Torque

#5 No, Torque 2D does not support pixel shaders. Torque 3D does, though.

This TDN article has some older code for TGB (as opposed to the current T2D) that might help get you moving in the right direction. It looks like it creates dynamic drop shadow sprites - or something like that.