Bug Half fragment shader precision instead float on Oculus Quest2

I use a RenderTexture (ARGBFloat), Graphics.Blit and a shader to calculate world position.
On Desktop build all works fine. But on the Quest (Android, vulkan) shader decreases precision of output to half instead float.
I tried:
1. Different sampler declarations:
Texture2D<float4> _Position;
SamplerState sampler_Position;
or
sampler2D_float _Position;
or
UNITY_DECLARE_TEX2D(_Position);
2. #pragma fragmentoption ARB_precision_hint_nicest
Nothing helps.

Is it possible to force using float precision on Oculus Quest?

 

Hi, relevant code.

Code (CSharp):

1. positionBuffer_1 = new RenderTexture(width, height, 0, RenderTextureFormat.ARGBFloat);
2. positionBuffer_1.filterMode = FilterMode.Point;
3. positionBuffer_1.autoGenerateMips = false;
4. positionBuffer_1.Create();
5. ...//prepare material and assign texture
6. Graphics.Blit(positionBuffer_1, positionBuffer_2, calculatePosition, 0);

For testing purposes I use light version of shader wich simply return float4 with constant. I also tried with suffix f.

Shader "GPUParticles/Internal/Position"

{

  Properties

  {

    _Position("Position", 2D) = "white" {}   

  }

  SubShader

  {

    Cull Off ZWrite Off ZTest Always

    Pass

    {

      CGPROGRAM

      #pragma vertex vert

      #pragma fragment frag



      #include "UnityCG.cginc"

      #include "../Includes/GPUParticles.cginc"



      sampler2D_float _Position;

      struct appdata

      {

        float4 vertex : POSITION;

        float2 uv : TEXCOORD0;

      };

      struct v2f

      {

        float2 uv : TEXCOORD0;

        float4 vertex : SV_POSITION;

      };

      v2f vert (appdata v)

      {

        v2f o;

        o.vertex = UnityObjectToClipPos(v.vertex);

        o.uv = v.uv;

        return o;

      }

      float4 frag (v2f i) : SV_Target

      {

        float4 pos = tex2D(_Position, i.uv);

        return float4(0.1f,500.12345f,500.12345f,1);

      }

      ENDCG

    }

  }

}

To check value in RenderTexture I use this code:

Code (CSharp):

1.         var textPoints = (RenderTexture)calculatePosition.GetTexture("_Position");
2.         RenderTexture.active = textPoints;
3.         Texture2D temp = new Texture2D(textPoints.width, textPoints.height, TextureFormat.RGBAFloat, false);
4.         temp.Apply(false);
5.         temp.ReadPixels(new Rect(0, 0, textPoints.width, textPoints.height), 0, 0);
6.         temp.Apply(false);
7.         RenderTexture.active = null;
8.  
9.         var positionArray = temp.GetPixels();
10.         for(int i = 0; i < 10; i++)
11.         {
12.             Debug.Log($"Positions {positionArray[i]}");
13.         }

At desktop I get:
Positions RGBA(0.100, 500.123, 500.123, 1.000)
At device through Logcat:
Positions RGBA(0.100, 500.000, 500.000, 1.000)

 

If I change RenderTexture format on RenderTextureFormat.ARGBHalf, problem become reproducable on Desktop. I also tried UnityEngine.Experimental.Rendering.GraphicsFormat.R32G32B32A32_SFloat, no sense.
From logcat I saw that device doesn't decrease texture precision and R32G32B32A32_SFloat is supported

 

Did you end up finding a way forward with this? We're seeing similar issues on iOS and Android. Reproducible when in the editor on those platforms on macOS, but not Windows. Also reproducible on iOS build.

 

I suggest a bug report if no staff responds