Graphics

Hi,

For a show I need to output a scene online, first without alpha, and then with alpha...

Is there a way to KF alpha channel ?

Thank you !

Put all the objects in the scene into a group object and then key frame the alpha of the group object.

In the 'Set Keyframe' menu make sure you have the alpha key selected (it should be in green).

#XPression

Garner, I'lm sure you're kidding me !

I have a scene with alpha, and what I want is to play it a first time on the fill channel but with alpha channel fully black, and then play it with fill and key together...

#XPression

Vincent, I was hoping you weren't asking about the actual scene render alpha - as that is not as easy to do! :)

We can't keyframe the scene render alpha (yet). So the only way to turn alpha on/off is by un-checking it manually or using the SDK.

From your description I think the easiest thing to do is duplicate your scene, and have one scene that has the alpha on and the same duplicate scene with the alpha off. Then you could just bring one on, take it offline and bring the other online. Not elegant but it should work ok.

If you want something more controllable you'll need to use a script that toggles the alpha on and off. A keyboard shortcut could be made that toggles the alpha on and off of a particular scene/group object. Let us know if you need help setting something like that up.

#XPression

By script ? How ?! Because playing with alpha will clear the fill channel, no ?

#XPression

All objects have an 'OutputAlpha' public property (True/False). This property will get and set whether the object will affect the output's alpha channel. This will toggle the alpha checkbox on the rendering tab:



A script would turn the alpha off of the object called 'Sphere1'. With the output alpha off the sphere object will only be shown on the Fill channel and not the Key/Alpha channel of the XPression output.

dim Sphere as xpBaseObject

self.getobjectbyname("Sphere1", Sphere)

Sphere.OutputAlpha = True

With a few more line of script you could make a keyboard shortcut that could toggle a scenes alpha on and off using a keyboard shortcut to run a script (in keyboard/GPI mapping). Like this:

dim scene1 as xpscene

dim output as xpOutputFramebuffer

dim Sphere as xpBaseObject

Engine.GetOutputFramebuffer(0, output)

output.getSceneOnLayer(0, Scene1)

Scene1.getObjectByName("Sphere1", Sphere)

if Sphere.OutputAlpha = True

Sphere.OutputAlpha = False

else Sphere.OutputAlpha = True

end if

You'll still need to put every object in the scene in one group and toggle the group objects outputalpha on/off to get the entire scene to turn alpha on/off.

Hope that's clear - let me know otherwise!

#XPression

Nice ! I'll try but it's the best way to do what I want !

#XPression