add changing colour background for flipbook sequence

[blendingshadow]

Hello,

 

I am making an explosion flipbook. The explosion flipbook rolls from hot to black smoke. 

 

As a game engine will need a diffuse and alpha I am looking for a way to 'bleed' the edges out for each frame so I don't get edging when it goes in game. 

 

I found the expand cop but would like to bleed it to the edge if possible. Do it uniquely for every frame in the flipbook. Add the original render over the top without changing the way it looks.

 

Any help would be great

 

Thanks

[Guest tar]

Not sure exactly what you need; would a soft edge mask on the edge of frame, fading to black, be enough

[blendingshadow]

Easier to explain, imagine a butterfly, looking top down at it. One side is blue the other yellow. I need to bleed / blend it to the background. The alpha will remain the same. 

 

It's just to stop the 1 pixel edging you get with changing colour values in a flipbook.

[Guest tar]

Sounds like un-premultipling ya?

 

It's always easier to post an image of your needs; i.e. the butterfly I imagine is cropped by the camera. Is yours?

[blendingshadow]

ahh good shout, I will have a look at the premultiply. I also had a look at using the channel copy with an expand node. It gives some decent results but isn't 100% accurate