Hello Forum,
does anybody know by any chance if it is possibel to draw a plane (Unity 5.6) in 3d space that is invisible to the camera but ist affecting alpha like a visible plane. Maybee a shader can do this?
thanks for any suggestions / help,
moon
There is a material/shader in 3D Max called matte shadow which provides this feature.
I know it is not Unity related - but might help you proceed with research.
Here is a related post - though the objective desired is a little different (because matte shadow material in Max provides for both casting shadow onto an invisible object and removing an invisible object from the alpha rendering)
Scroll down to about post #30 where they start producing results.
Also consider looking into duel cameras and/or the render buffers (depth and z).
Additional info that might help
O.K., yes, I know the 3DS Max matte shadow material and it´s purpose. I´ve already used it i Maya (theres an similar thing) to render a car in front of an HDR, to produce shadows on the “bottom of the HDR”. As I have no programing skills at all, I doubt to be able to rewrite the shader from thread 1 to what I need for Unity 5.6 +, but it´s close! I already have found both threads and read them, the second won´t help me @ all, because there is nothing opake in front of the plane to be rendered.
As you said, the objective is a little different.
I will need a shader that gets:
the only thing the invisible plane should do is to affect alpha (clear out everything beyond it). It has not do be double sided.
I thought maybee there ist something like this, I just don´t know it. Could not imagine anyone be4 me didn´t need something like this…
thanx for your reply…