Invisible object casting shadows

Support Materials and Textures
1

Hi, I want to render some clouds in BI renderer with some shadows on top of them of an airplane. But the airplane casting the shadows can not be visible.
Turning down the alpha did not help, neither did searching for this on the forum or google. (yes, I did do it. ;))

Can someone help?

Thanks!

2

Check “Cast Only” In the “Shadow” tab for the plane’s material:


3

thank you!