From Ren'Py Visual Novel Engine
||Dissolve||(time, old_widget=None, new_widget=None, alpha=False):|
This dissolves from the old scene to the new scene, by overlaying the new scene on top of the old scene and varying its alpha from 0 to 255. Dissolve only works correctly when both scenes are the same size.
time - The amount of time the dissolve will take.
alpha - If True, the resulting displayable will have an alpha channel, at the cost of some speed. If False, it will be treated as opaque, but be faster.
init: $ dissolve = Dissolve(0.5) with None scene bg whitehouse show eileen happy with dissolve e "The dissolve transition is probably the most useful, blending one scene into another."