Question How to make a URP VR portal?

Hi,
From what i read about the Render method in builtin you needed to disable the camera https://docs.unity3d.com/ScriptReference/Camera.Render.html, i did the same with RenderSingleCamera for URP but i see the method just executes in case i have the camera component active, i am not sure if having the camera active is fine or can have any problem, cause i am using two rendersinglecamera, one for each eye, but i camera doesn't actually render the objects belonging to the culling mask it has. I am applying to each camera stereo matrix for each eye, like this for left eye currentCamera.GetStereoProjectionMatrix(Camera.StereoscopicEye.Left);. Seems the projection matrix is wrong as if i don't change the camera matrix i can see the objects for each eye but wrong when i see with both eyes

 

I also noticed that objects look nearer than they should be, tried col = tex2D(_LeftTex, UnityStereoScreenSpaceUVAdjust(i.uv, _LeftTex_ST)); in shader instead col = tex2D(_LeftTex, screenUV); using float2 screenUV = i.screenPos.xy / i.screenPos.w; but doesn't work, just show the objects smaller
Also rotation is wrong, seems camera projectionmatrix is not correct

 

This is my code

Code (CSharp):

1.  
2.     private void OnEnable()
3.     {
4.         //UnityEngine.XR.XRSettings.gameViewRenderMode = UnityEngine.XR.GameViewRenderMode.BothEyes;
5.         RenderPipelineManager.beginCameraRendering += UpdateCurrentCam;
6.     }
7.  
8.     private void OnDisable()
9.     {
10.         RenderPipelineManager.beginCameraRendering -= UpdateCurrentCam;
11.     }
12.  
13.     void Start()
14.     {
15.         meshRenderer = GetComponent<MeshRenderer>();
16.     }
17.  
18.     void UpdateCurrentCam(ScriptableRenderContext context, Camera currentCamera)
19.     {
20.         if (meshRenderer != null && currentCamera.gameObject.name == "PortalCamera")
21.         {
22.             currentCamera.projectionMatrix = currentCamera.GetStereoProjectionMatrix(Camera.StereoscopicEye.Left);
23.             UniversalRenderPipeline.RenderSingleCamera(context, currentCamera);
24.             meshRenderer.material.SetTexture("_LeftTex", currentCamera.targetTexture);
25.             currentCamera.projectionMatrix = currentCamera.GetStereoProjectionMatrix(Camera.StereoscopicEye.Right);
26.             UniversalRenderPipeline.RenderSingleCamera(context, currentCamera);
27.             meshRenderer.material.SetTexture("_RightTex", currentCamera.targetTexture);
28.         }
29.     }

 

I have seen code from other projects and they use obliquematrix but don't know why, what does obliquematrix? If i transform matrix with obliquematrix and it renders the box column in front of the camera but wrong. I have set the same models for both dimensions but the portal camera renders wrong scale and rotation, i have set the portal camera as child of main camera but render just the culling mask for objects in the other dimension