Bug LinearBlendSkinning has a render bug

I wrote a shader manually like this：

Code (CSharp):

1.  
2. uniform ByteAddressBuffer _SkinMatrices;
3.  
4. half3x4 LoadSkinMatrix(int index)
5. {
6.     int offset = index * 48;
7.     half4 p1 = asfloat(_SkinMatrices.Load4(offset + 0 * 16));
8.     half4 p2 = asfloat(_SkinMatrices.Load4(offset + 1 * 16));
9.     half4 p3 = asfloat(_SkinMatrices.Load4(offset + 2 * 16));
10.     return half3x4(p1.x, p1.w, p2.z, p3.y,p1.y, p2.x, p2.w, p3.z,p1.z, p2.y, p3.x, p3.w);
11. }
12.  
13. void Unity_LinearBlendSkinning_float(int4 indices, half4 weights, half3 positionIn, half3 normalIn, out half3 positionOut, out half3 normalOut)
14. {
15.     positionOut = 0;
16.     normalOut = 0;
17.     for (int i = 0; i < 4; ++i)
18.     {
19.       int skinMatrixIndex = indices[i] + UNITY_ACCESS_HYBRID_INSTANCED_PROP(_SkinMatrixIndex, int);
20.       half3x4 skinMatrix = LoadSkinMatrix(skinMatrixIndex);
21.       half3 vtransformed = mul(skinMatrix, half4(positionIn, 1));
22.       half3 ntransformed = mul(skinMatrix, half4(normalIn, 0));
23.  
24.       positionOut += vtransformed * weights[i];
25.       normalOut += ntransformed * weights[i];
26.    }
27. }
28.  

And the fragment shader like this:

Code (CSharp):

1.  
2. half4 frag(Varyings input) : SV_Target
3. {
4.     UNITY_SETUP_INSTANCE_ID(input);
5.  
6.     half3 worldSpaceNormal = input.normalWS.xyz;
7.  
8.     half3 mainTexColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, input.texCoord0.xy).rgb;
9.     mainTexColor = saturate(mainTexColor);
10.  
11.     half3 mainLightDir = half3(0.5h, 0.5h, 0.0h);
12.  
13.     half dotProduct = dot(mainLightDir, worldSpaceNormal);
14.     half3 diffuse = saturate(dotProduct * mainTexColor);
15.  
16.     half3 ambient = mainTexColor * 0.4h;
17.  
18.     half3 color = diffuse + ambient;
19.  
20.     half3 finalColor = lerp(color, _BaseColor, _ColorLerp);
21.  
22.     return half4(finalColor, 1.0h);
23. }
24.  

And the vertex shader like this:

Code (CSharp):

1.  
2. Varyings vert(Attributes input)
3. {
4.     Varyings output = (Varyings)0;
5.  
6.     UNITY_SETUP_INSTANCE_ID(input);
7.     UNITY_TRANSFER_INSTANCE_ID(input, output);
8.  
9.     half3 linearBlendSkinnedPosition = 0;
10.     half3 linearBlendSkinnedNormal = 0;
11.     Unity_LinearBlendSkinning_float(input.indices, input.weights, input.positionOS, input.normalOS,
12.         linearBlendSkinnedPosition, linearBlendSkinnedNormal);
13.  
14.     half3 positionWS = TransformObjectToWorld(linearBlendSkinnedPosition);
15.     half3 normalWS = TransformObjectToWorldNormal(linearBlendSkinnedNormal);
16.  
17.     output.normalWS = normalWS;
18.     output.positionCS = TransformWorldToHClip(positionWS);
19.     output.texCoord0 = input.uv0;
20.     return output;
21. }
22.  

This shader, on the Redmi Note3 and other phones, renders objects completely black. However, I changed the shader code as below and the render color was correct.

Code (CSharp):

1.  
2. Varyings vert(Attributes input)
3. {
4.     Varyings output = (Varyings)0;
5.  
6.     UNITY_SETUP_INSTANCE_ID(input);
7.     UNITY_TRANSFER_INSTANCE_ID(input, output);
8.  
9.     half3 linearBlendSkinnedPosition = input.positionOS;
10.     half3 linearBlendSkinnedNormal = input.normalOS;
11.  
12.     half3 positionWS = TransformObjectToWorld(linearBlendSkinnedPosition);
13.     half3 normalWS = TransformObjectToWorldNormal(linearBlendSkinnedNormal);
14.  
15.     output.normalWS = normalWS;
16.     output.positionCS = TransformWorldToHClip(positionWS);
17.     output.texCoord0 = input.uv0;
18.     return output;
19. }
20.  

My Unity editor version is 2022.2.15, and DOTS version is 1.0.pre65.
LinearBlendSkinning node of ShaderGraph is used to write the same shader as above, with the same problem.

 

Are the positions in the correct locations? And it is just the normals that are wrong? Is ambience being added correctly?

 

Positions are in the correct locations.

mainTexColor * 0.4h

looks like 0. The ambience looks like black. Strangely,

mainTexColor * 0.9h

also looks like 0, but

mainTexColor * 1.0h

looks like correct.
It's fine not to use

LinearBlendSkinning

, but whenever you use it, you get an error.

 

I have three phones. Two of them are wrong.