my render is coming out showing the ground plane though and I am not getting transparency. The alpha also just shows a solid plane with no transparency for the shadow.
how can I get just a transparent shadow and not see the whole ground plane?
Can you post your scene file to check the entire lighting and material setup? If there are any confidential models or textures, you can replace them with simple primitives.
but I still wonder how to post such things here.
You can add file attachments only in Advanced post mode. Just click on “Go Advanced” button on the bottom right side of the page. Then you will see a new “Attachment” icon on the toolbar.
Or you can send us the file (or a download link) to support at chaosgroup.com
I see that you are using a V-Ray dome light for this setup. It produces very soft shadows on the ground plane and makes it visible in the final render.
So you can either decrease (can be set to zero) the "GI amount"parameter in the V-Ray Wrapper material > Matte properties section, or uncheck the “Affect alpha” option in the V-Ray Dome light attributes.
Let me know if this helps you.
I tried both of your suggestions and saw no difference though. Also turned off the dome light and tried using a vray rectangle light, and still saw no difference with how the plane is behaving.
As far as I understand you’re trying to render the plane as a matte object (shadow catcher), is that correct?
If this is the case, there’s a couple of ways to do that - either using a wrapper material or vray object properties. There is a wrapper Mtl in your scene, but it’s not assigned to the ground plane. The wrapper settings are correct, though.
