How to take jus t the shadow cast into Photoshop

[WWX]

Hi I have read some of the posts on matte object but still have not been able to do the following.

I am working on a photo montage. The photo show the road and I have now place a car or two which needs to cast their shadows onto the street, which is part of the photo.

I tried to place a plane and make it an VRay matte object and do the same for the car as the only entity I want on a seperate layer in PhotoShop is just the shadows cast, but haven't succeeded.

Please advice.

Thanks

[Candelero]

You need to have the Alpha Contr. set to -1 on the plane object.
That is in the VRayMtlWrapper. Then Check on the Shadows.
In the G-Buffer section , select also Shadows.

Best regards,
nikki Candelero

[peterC]

Just rightclick your object / vraypropertys
matteobject ON
Alpha contribution -1
check shadows and affect alpha also.
this way you dont need to wrap your material in the vrayMaterial wrapper.
Peter

[WWX]

Thanks for the tips guys. I basically have been doing just that, but just going through the render dialog box.

The problem is this does not provide me with what I am looking for.

Here are 3 iamges showing my settings and the results I get.







At present I have both the ball and its shadow outline in the alpha channel and I would only like to have the shadow.

The shadow pass display totally black.

[RErender]

In vray props for the sphere, just set alpha contribution to -1 ?

[WWX]

Thanks Eric