Unsure of the best way to go about achieving this
I was wondering if anyone had any suggestions on the best way to achieve the following.
I'm basically rendering out an animation from Maya and comping it together in After Effects, I will be rendering one colour layer, and an ao layer, and a layer with a black surface shader on everything, except the sky, so the sky is pure white, which i can use as a mask layer.
What id like to achieve is to get a blooming effect on the sky, where the light/sunlight/skylight is blurred and screened over the top of the trees. I have no trouble achieving this in Photoshop for a still layer, as shown in the first shot. I simply select the pure white of the sky in the ao layer, select the sky from the colour layer, copy and paste it over the top of everything, blur it, and screen the result. Easy.
But having tried this in a similar project recently I know that doing the same thing for an animation isnt quite so easy. That time I rendered a seperate layer where everything was pure black(surface shader), leaving the sky as pure white, hoping that I could use the white as a mask for the sky, and then applying the blur to that and screening it. But what ended up happening was that the blur that i applied took the mask with it, so where some of the white from the sky took the bloom effect over the trees (as intended) the black from the mask also blurred over to the sky, creating a horrible grey border region around the outline of the trees which just didnt look good. (the regions marked in red in image 2)
Im by no means profficient with After Effects, so perhaps I was applying the mask the wrong way, but I did try many configurations and none of them achieved what i would have thought was a pretty simple and standard operation.
Can anyone help with ideas of the best way to do this.
CGI Artist - Data Model Specialist