Transparent ground plane with shadow?? I'm stumped.

[redbyte]

Hey guys,
I've spent around an hour searching the forums, and reading the manual, but I can't seem to find an answer.

I'm trying to create a material that can be used on a plane, that accepts shadows only, but is otherwise transparent.
Here's a quick blender internal render of what I'm trying to achieve in indigo:



Is this possible?? I've experimented with a null material, blended with a diffuse, but I'm very new at this and don't quite understand it.

All help is very much appreciated!!

Thanks in advance

[Anthony]

I don't think it's possible because that material is impossible in real life :S

[neepneep]

It's not possible at the moment....but I hope it's possible in the future...

....I see maxwell has a shadow channel material

[redbyte]

Wow. You gotta be kidding me...

How do people do car renders then? With the car sitting out on a photo of street?

Oh well. I guess I'll just wait I spose
Thanks for the responses guys.

[Anthony]

Model the street. Then you can brag when indigo spits out a kick ass image

[Kram1032]

yup, streets usually are modelled

[Grimm]

You can also use an EXR map, but you would still probably want to model the foreground to get shadows, etc.

[Zom-B]

Wow. You gotta be kidding me...

How do people do car renders then? With the car sitting out on a photo of street?

Here is the way I did it...

[CTZn]

Or you could do a shadow pass in blender internal and use it to cut the ground's alpha...