Emulating Grass, Pebbles, etc for Ground Shadows...

How can I make a simple, irregular floor surface to shadow cast onto (as image below - please ignore highlighted red ellipses) which can emulate the look of grass, pebbles, etc…?


I’ve tried displacement mapping, but I just get a crazy mass of pyramids, even with the disp level set low.

I don’t need accuracy - I just want to break up the edge of the ground shadow appropriately depending on where the character walks. Surely there’s an easy method for this…?

Have you tried normal mapping?

My understanding is that normal mapping is just a render effect, the surface isn’t physically distorted, and shadows falling on them will apppear flat…I could be wrong though…

Currently the only option I know that will work is adding a mesh for the ground and subdivide a gazillion times - maybe with a fractal subdivide - then apply a subsurf, maybe converting back to mesh after that. (!)

I’m just reluctant to add so many vertices for a fairly minor effect.

Damn - just tried with a seriously normaled plane - shadow as flat as a pancake!

Have you tried using an area light to soften the edges of the shadow instead of a standard lamp?

Yes, this looks okay for a while untill the creature walks from grass to pebbled path or vica versa, but the shadow looks consistent.

I guess the next level of complexity would be to model a plane with subdivisions (But not thousands !) so that it matches the line of the ground and rise slightly where the grass meets the pebbles, and dips dowl a little as it goes into the grass. That way, the shadow will, at least, follow the shape of the terrain if not the texture.

It might just be enough.

Yeah, I have done that on some shots - I guess I was just hoping for a better solution…

Thanks for your help so far!