soft shadows and accumulation buffer

[Sabonis]

I have created soft shadows by jittering lights..
I draw the entire scene and accumulate it then
I slightly move the light and I redraw the entire scene.
Finally I return the scene composed by the accumulated frames.
The problem is that I redraw the entire scene
even if only the shadow must to be redrawn.
Is possible to redraw only the shadow??
I want to draw the objects only once and then
I want to use the accumulation buffer for the lights.

[Hlz]

Is possible to redraw only the shadow??What do you mean? Can you post your code?

[powerpad]

maybe you can use the stencil buffer to mask regions that don't need to be drawn at all