Unity - portals discussion and rendertexture help needed.

Hello Impereativity.

Thanks for the reply who is well thought out.
This is indeed what I do and what can be seen on the video.
However there is still an issue.
I made a small schematic here to explain my issue.

The issue here is that -if you can see both portals-, one of them is always going to have its image in front of the other one if, indeed, its camera is oriented towards terrain. . In this case, the blue 1 camera image always appears on top of the red 1 camera, causing the issue we see on the screenshot. I drastically limited the issue by deactivating a portal's camera(s) if you don't look at it but I still get this issue. 
Is there a way to have a shader render only one specific camera instead of having to resort to render order ?
I'm still very new to rendering issues and I haven't had the chance to find a decent free tutorial on shaders that I could understand properly :neutral:
Maybe there's something I'm doing wrong or I'm not using the right technique ?
Cheers.

Yoirgl.

@imperativity
*erm*
Well you lost me at "directed acyclic graph
of cameras" :#
I'm trying to read wikipedia articles and try to understand what you mean :)
(as I said i'm still quite new to this ^^)
brb.

@imperativity
Hello again.
I think I understood what you meant but in this case, recursivity is not really the issue.
The issue happens even with recursivity set to 0 (I made it dynamic). -0 meaning only one camera per portal-
I'm just not entirely certain what you meant by "clear the depth". If you mean set the camera's clear flags to depth only, yes that is the case and that is also part of what's causing me so much troubles. .
The problem I have, as you can see in the small screen capture below, is that I cannot render both camera on 2 different depths without them "polluting" one another in certain cases. (check the depth modification on 2nd portal camera) .

https://youtu.be/Yl_WvTZq_LE

In the video if i change the depth on the camera to a value between 0 and -0.5 it'll seems OK but it won't be because then my blue portal will suffer the same issue as the red one. (although not visible on the current angle.)
I tried scissoring the screen to only render what was around the portal
per camera but that doesn't seem to work with a VR camera
Did I understand you correctly or is my problem a bit clearer ?
It's quite tricky to explain precisely.

Yoirgl.

@imperativity said:

@Yoirgl

To further clarify: you will need to depth clear after each
portal render. You will also need to mask the region of UserCamera's view where
Portal1 appears before rendering Portal2.

Hope this helps you!

Hello.

Well, unfortunately it doesn't. :'(
I think you have a different vision of mine but i can't quite grasp your idea.
Could you try and explain it to me o:) ? 
Thank you for your replies.

Yoirgl.

PS : is there no way to hack the view bypass to get the rendertextures to behave properly ?
Using a rendertextures removes a whole bunch of other issues at once.


edit : I was able to achieve some level of success using stencil buffers+depth
masks but the result is quite unstable and i sometimes get some degree
of "judder" (not 100% reproducible)

@imperativity
Well, I got it to work to some extent :)
Still have a bug list longer than my arm but at least the major bug is now behind me.
https://www.youtube.com/watch?v=FMfu7XGBHUw
Thanks for your input.

Yoirgl.