realistic shadow map - how to do?

I would really like do add a shadowmap to an area light.

I mean this:
When light falls into a room, there is a shadow of a tree from the outside.
But i don’t want to model this tree, i only want to add a shadow map to the lamp that casts these shadows.

I tried this for my lightsources (area lights; i added a texture [vororoni crackle] to the lamp) but shadows are

  • much too sharp
  • not realistic
  • and don’t become larger when an object is farer away than another one (i only think that, i didn’t prove that point yet)

What will i have to do to get realistic shadows without a model?

Or did i Just something wrong?

K, what I did was make an alpha texture of a black tree on a transparent background. Just map the tree texture to the spotlight itself with UseAlpha on. In the spotlights MapTo, change it from global to View to get the perspective thing going. The shadow sharpness doesn’t seem to get me excited, I just made the tree texture fuzzy around the edges.

Edit: Using a raytrace spotlight helps a lot it seems. Looks better now.

Thx, i will try that!