Stereo Eye Index for video

[shanks]

Hi @Cotta 

I have the same problem : unit_StereoEyeIndex is always 0 when I publish to the device，but effective on Unity Editor。

Below is my environment:

• Unity 2018.4.25
• Wave SDK 3.1.94
• Focus Plus

This is my shader:

Shader "Unlit/TestSinglepass"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 100

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
                UNITY_VERTEX_OUTPUT_STEREO
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

            v2f vert (appdata v)
            {
                v2f o;
                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);

                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
              UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(i);

              fixed4 col = fixed4(0, 0, 0, 1);

              if (unity_StereoEyeIndex == 0)
              {
                col = fixed4(1, 0, 0, 1); // Left:red
              }
              else 
              {
                col = fixed4(0, 1, 0, 1); // Right:green
              }

                return col;
            }
            ENDCG
        }
    }
}

Thanks for help. @Tony PH Lin @Corvus

[GoranW]

Was this confirmed to work? I'm trying to get it working on VIVE Focus 3 using VIVE Input Utility (VIU).

Same scene + shader is working on Quest 2 via Oculus XR in VIU, but if I switch to Wave XR in VIU then unit_StereoEyeIndex is always 0 (in frag shader), both for Single-pass and Multi-pass rendering.

@Dario Any clue?

[GoranW]

OK, after some more testing I can conclude that with Wave XR, unit_StereoEyeIndex only works in vert shader but not in frag shader.

This is in contrast to Oculus XR, where it works fine in frag shader as well.

A workaround is to pass the value on from vert shader to frag shader.

Edited March 3, 2022 by GoranW