Rendering objects behind and in front of an image plane?

[Anonymous]

Two quick questions

I have an image plane attached to a perspective camera. I would like to be able to render, with Arnold, objects behind and in front of the image. Right now when I render with Arnold all my objects always appear in front of the image plane even though in the viewport the object is behind the image and obscured by it. Can someone lend a hand?

One more Q. I also noticed that the image plane only renders in Arnold if I am looking out of the camera with the attached image plane in the viewport. Of course, I do have the correct camera selected in the Arnold Renderview settings, but the image plane does not render, again, unless I am actually looking out of the camera in the viewport. How can I fix this?

Thank you for the help,

Ian

[Anonymous]

Hey

so you basically want to have the image plane as an element as part of you scene? Instead of using it as an image plane, you might want to project the image onto an object (plane) in the scene. 

Place a plane in space where you want to have the image, project the image onto that object. For the projection use the camera that you are using with the image plane at the moment.  (here is one of many camera projection tutorials you can find on youtube https://www.youtube.com/watch?v=YpB6AOm0SW0)

does that help?

[Anonymous]

Yes that's right! I will watch the tutorial.

What I like about image planes is they just work, no need to light the
object or anything and png transparency works so easily.

I guess there's no way to put objects behind an image plane and have them
obscured by the image plane in arnold render?

I've tried to mess with exporting an iff from photoshop and turning on
z-depth in maya, but I have no idea how to get that to work properly.

Thank you for the help.

[Anonymous]

Hey,

well you definitely CAN render an image plane. There is a thread about how to do it here. Also make sure that the image plane display attributes are set to "visible in all cameras" if the camera you are using for the image plane is not the one you render.  

https://forums.autodesk.com/t5/maya-shading-lighting-and/rendering-image-planes/td-p/6904122

but generally I'd rather not to do that. Instead use a projection set up. If you don't want any lighting to be applied to your projected texture, use a Arnold Flat shader. The shader is not affected by any lighting. 

[RobH2]

I know this is an old thread but the original question got sidetracked and not discussed. I'd like to know if you "can" in fact render an object that is occluded by another. Say you had a rock behind a wall and for some odd reason, you'd want that occluded rock to render as if it were being seen through the wall. Not xray, but render on top or in front of the wall. Simply, is there a way to force an occluded object to render in front of everything? It would not move, it would just render. 

Not sure if I'm explaining it well. 

[Anonymous]

Mhm you could render the occluded object on a separat layer and then put it on top in a compositing software? Would that help?