fade in/fade out

[Ameshi]

Anyone tried to do this? like use fade in/fade out when changing scenes/maps?

 

I guess I can use a black image and apply alpha values to do the trick?

[Rick]

Yes, but draw a rectangle with the context commands instead of an image so you don't require an external resource.

[xtom]

Funnily enough I just coded a function for this today...

 

I put the function below in the player script and then use the following to call to run and check it in post render...

 

if self:FadeScreen(0,100) == true then

-- screen has now faded to black

end

 

 

if self:FadeScreen(1,100) == true then

-- screen has now faded from black

end

 

It seems to work pretty good but if anyone spots anything dodge in the code let me know. Still learning lua as I go.

 

-- fades screen to black
-- fade 0 fade to black
-- fade 1 fade from black
-- speed eg. 10=fast 100 slow
function Script:FadeScreen(fade,speed)
local screenWidth = App.context:GetWidth()
local screenHeight = App.context:GetHeight()
if fade>0 then
-- fade from black
if self.fadeValue == nil then self.fadeValue=speed end

local alpha = self.fadeValue/speed
if alpha<=0 then alpha=0 end
App.context:SetBlendMode(Blend.Alpha)
App.context:SetColor(Vec4(0,0,0,alpha))
App.context:DrawRect(0,0,screenWidth,screenHeight)

if self.fadeValue <= 0 then
self.fadeValue = nil
return true
end

self.fadeValue = self.fadeValue-1

else
-- fade to black
if self.fadeValue == nil then self.fadeValue=1 end

local alpha = self.fadeValue/speed
if alpha>1 then alpha=1 end
App.context:SetBlendMode(Blend.Alpha)
App.context:SetColor(Vec4(0,0,0,alpha))
App.context:DrawRect(0,0,screenWidth,screenHeight)

if self.fadeValue >= speed then
self.fadeValue = nil
return true
end

self.fadeValue = self.fadeValue+1
end

return false

end

[Rick]

The only thing, that probably doesn't affect you since you are using a Lua project, would be to get the context via Context:GetCurrent() instead of App.context as C++ projects don't have the App object so the script won't work in a C++ project. By having Context:GetCurrent() to get the context it'll work on both projects. That's obviously detailed but it's something that we all found out early on with scripts in the Workshop after the C++ projects were released in LE (Lua only was the first project type released in LE so everyone just used the App object without understanding the issues with it in C++ projects that would come later on).

[xtom]

Ah thanks, I will bear that in mind going forward.

[randomkeyhits]

This one is on my todo list and I was going to have a go using camera post effects.

 

The simplest idea was to have a straight fade in/out to a specific colour, black or white being the two most obvious.

 

If that worked well I was then going to look at building a small library of shaders for transition effects, fades, page turns, melts, pixellates, all those kind of things.