Is there a way to make the ground plane invisible when rendering YET still render the eco system that is on the ground plane?

For example, I am trying to composite small bushes & grass patches over an image.

The bushes are created via Eco system on a plane. If I "hide" the Plane, the eco system hides as well.

  Basically, I am trying to get the same results that you would Using MAYA . In Maya you would assign a "USE BACKGROUND SHADER" to the plane making the plane transparent and only showing the shadows.

Thanks,

lou

Just make the basic material (the ground) transparent in the materials menu.

but will the shadows remain? I thing any shadows will not cast on the image if the surface gets a transparent material

Vue does not have shadow catching, unfortunately.  It does make an attempt at it though when using the Environment mapping atmosphere model.  But it is a joke (think 1994 rendering technology).

You'll need to import your plants into a rendering app that has shadow catching.

NOTE:  In this Vue rendered video http://www.youtube.com/watch?v=Ot6593zKBSE there are no tree shadows on the ground, even though a shadow pass was apparently rendered.  That shadow pass would have to be used in another rendering app anyway.

It's hard to tell from the image you've provided, but can you position the plane just below the terrain, so the plane disappears, but the plants still remain? that way the shadows should still cast on the terrain.

That's part of the magic being tried.  There is no "terrain" except in the background photo.  Only the plane and plants exist.

surely try using the eco-painter on the terrain, then move or delete the terrain. 

The eco objects will remain but the terrain will be gone.

Quote - surely try using the eco-painter on the terrain, then move or delete the terrain.  The eco objects will remain but the terrain will be gone.

And so will be gone the shadows, unfortunately.

For example, try to do this in Vue http://www.youtube.com/watch?v=-ebI3AOVx_Q

I admit there is not much shadow (object is in the shade).  But you get the idea.