I have an OBJ of a pack that I am placing into a 2d background. It is being placed down onto a table top and I would like to cast a shadow as it comes in. Using the new lighting it appears i have to create a floor, or in my case table top, that I wish it to cast onto. But my table is part of the flat 2D background. I have tried fooling it by putting in a fake layer casting the shadow on this and then turning the opacity to 100 or hiding the layer but the shadow disappears. Is there a way to cast a shadow onto a 2D background using lights or do I have to make my own with a spline or a darkened image of the original object flipped and positioned seperately. I have noticed that I am able to cast a shadow and render out a matte run and then I could reinsert this on another layer but each time i change the position/trajectory of the OBJ i have to re-render this matte run. Would be great if I could fool it to let me do it in one render.
theres no "shadow catching object" in smoke (like in 3d packages) -
you can render the final comp + a shadow map out & comp that afterwards. - or texture the fake floor/desktop with the image, so it integrates into the shot .