Possible to mask area on Flat pano so that snow can fall over it?

Hi.

Is it possible to mask something on a flat panorama so that only certain areas of the image have an effect added to them? In my case I wanted snow to just fall only where the window panes are (shown in red on the attached image). Everything else would be on the inside of the room so the snow wouldn’t fall.

I’ve used the exported tif file from Blender to create the ‘flat’ multires panorama so that people can zoom in and out slightly just to see the detail of what’s on the inside window ledge and also the view outside so whatever I use for the masks needs to stay in place while the image is zoomed slightly.

Can’t seem to get my head around whether or not this is possible in KRPano.

Thanks for any help.

Andrew

Thanks very much for the information Tuur. I'll read up more on your suggestions and see if it's something I can set up relatively easily. If it's a massive job I'll have to look at masking in something like Premiere Elements. I did really want to use KRPano though as haven't had the chance to use it for ages.

I thought about a short animation clip in Blender but it takes 4 hours to render that single image in blender on my PC for the size I want it so adding snow coming down would be never ending.

How about Panimator, but I guess that would include rendering also?